Merge branch 'feat/tagfunc'

[vim_extended.git] / src / misc2.c

/* vi:set ts=8 sts=4 sw=4:
 *
 * VIM - Vi IMproved    by Bram Moolenaar
 *
 * Do ":help uganda"  in Vim to read copying and usage conditions.
 * Do ":help credits" in Vim to see a list of people who contributed.
 * See README.txt for an overview of the Vim source code.
 */

/*
 * misc2.c: Various functions.
 */
#include "vim.h"

static char_u   *username = NULL; /* cached result of mch_get_user_name() */

static char_u   *ff_expand_buffer = NULL; /* used for expanding filenames */

#if defined(FEAT_VIRTUALEDIT) || defined(PROTO)
static int coladvance2 __ARGS((pos_T *pos, int addspaces, int finetune, colnr_T wcol));

/*
 * Return TRUE if in the current mode we need to use virtual.
 */
    int
virtual_active()
{
    /* While an operator is being executed we return "virtual_op", because
     * VIsual_active has already been reset, thus we can't check for "block"
     * being used. */
    if (virtual_op != MAYBE)
        return virtual_op;
    return (ve_flags == VE_ALL
# ifdef FEAT_VISUAL
            || ((ve_flags & VE_BLOCK) && VIsual_active && VIsual_mode == Ctrl_V)
# endif
            || ((ve_flags & VE_INSERT) && (State & INSERT)));
}

/*
 * Get the screen position of the cursor.
 */
    int
getviscol()
{
    colnr_T     x;

    getvvcol(curwin, &curwin->w_cursor, &x, NULL, NULL);
    return (int)x;
}

/*
 * Get the screen position of character col with a coladd in the cursor line.
 */
    int
getviscol2(col, coladd)
    colnr_T     col;
    colnr_T     coladd;
{
    colnr_T     x;
    pos_T       pos;

    pos.lnum = curwin->w_cursor.lnum;
    pos.col = col;
    pos.coladd = coladd;
    getvvcol(curwin, &pos, &x, NULL, NULL);
    return (int)x;
}

/*
 * Go to column "wcol", and add/insert white space as necessary to get the
 * cursor in that column.
 * The caller must have saved the cursor line for undo!
 */
    int
coladvance_force(wcol)
    colnr_T wcol;
{
    int rc = coladvance2(&curwin->w_cursor, TRUE, FALSE, wcol);

    if (wcol == MAXCOL)
        curwin->w_valid &= ~VALID_VIRTCOL;
    else
    {
        /* Virtcol is valid */
        curwin->w_valid |= VALID_VIRTCOL;
        curwin->w_virtcol = wcol;
    }
    return rc;
}
#endif

/*
 * Try to advance the Cursor to the specified screen column.
 * If virtual editing: fine tune the cursor position.
 * Note that all virtual positions off the end of a line should share
 * a curwin->w_cursor.col value (n.b. this is equal to STRLEN(line)),
 * beginning at coladd 0.
 *
 * return OK if desired column is reached, FAIL if not
 */
    int
coladvance(wcol)
    colnr_T     wcol;
{
    int rc = getvpos(&curwin->w_cursor, wcol);

    if (wcol == MAXCOL || rc == FAIL)
        curwin->w_valid &= ~VALID_VIRTCOL;
    else if (*ml_get_cursor() != TAB)
    {
        /* Virtcol is valid when not on a TAB */
        curwin->w_valid |= VALID_VIRTCOL;
        curwin->w_virtcol = wcol;
    }
    return rc;
}

/*
 * Return in "pos" the position of the cursor advanced to screen column "wcol".
 * return OK if desired column is reached, FAIL if not
 */
    int
getvpos(pos, wcol)
    pos_T   *pos;
    colnr_T wcol;
{
#ifdef FEAT_VIRTUALEDIT
    return coladvance2(pos, FALSE, virtual_active(), wcol);
}

    static int
coladvance2(pos, addspaces, finetune, wcol)
    pos_T       *pos;
    int         addspaces;      /* change the text to achieve our goal? */
    int         finetune;       /* change char offset for the exact column */
    colnr_T     wcol;           /* column to move to */
{
#endif
    int         idx;
    char_u      *ptr;
    char_u      *line;
    colnr_T     col = 0;
    int         csize = 0;
    int         one_more;
#ifdef FEAT_LINEBREAK
    int         head = 0;
#endif

    one_more = (State & INSERT)
                    || restart_edit != NUL
#ifdef FEAT_VISUAL
                    || (VIsual_active && *p_sel != 'o')
#endif
#ifdef FEAT_VIRTUALEDIT
                    || ((ve_flags & VE_ONEMORE) && wcol < MAXCOL)
#endif
                    ;
    line = ml_get_buf(curbuf, pos->lnum, FALSE);

    if (wcol >= MAXCOL)
    {
            idx = (int)STRLEN(line) - 1 + one_more;
            col = wcol;

#ifdef FEAT_VIRTUALEDIT
            if ((addspaces || finetune) && !VIsual_active)
            {
                curwin->w_curswant = linetabsize(line, pos->lnum) + one_more;
                if (curwin->w_curswant > 0)
                    --curwin->w_curswant;
            }
#endif
    }
    else
    {
#ifdef FEAT_VIRTUALEDIT
        int width = W_WIDTH(curwin) - win_col_off(curwin);

        if (finetune
                && curwin->w_p_wrap
# ifdef FEAT_VERTSPLIT
                && curwin->w_width != 0
# endif
                && wcol >= (colnr_T)width)
        {
            csize = linetabsize(line, pos->lnum);
            if (csize > 0)
                csize--;

            if (wcol / width > (colnr_T)csize / width
                    && ((State & INSERT) == 0 || (int)wcol > csize + 1))
            {
                /* In case of line wrapping don't move the cursor beyond the
                 * right screen edge.  In Insert mode allow going just beyond
                 * the last character (like what happens when typing and
                 * reaching the right window edge). */
                wcol = (csize / width + 1) * width - 1;
            }
        }
#endif

        idx = -1;
        ptr = line;
        while (col <= wcol && *ptr != NUL)
        {
            /* Count a tab for what it's worth (if list mode not on) */
#ifdef FEAT_LINEBREAK
            csize = win_lbr_chartabsize(curwin, ptr, col, &head, pos->lnum);
            mb_ptr_adv(ptr);
#else
            csize = lbr_chartabsize_adv(&ptr, col, pos->lnum);
#endif
            col += csize;
        }
        idx = (int)(ptr - line);
        /*
         * Handle all the special cases.  The virtual_active() check
         * is needed to ensure that a virtual position off the end of
         * a line has the correct indexing.  The one_more comparison
         * replaces an explicit add of one_more later on.
         */
        if (col > wcol || (!virtual_active() && one_more == 0))
        {
            idx -= 1;
# ifdef FEAT_LINEBREAK
            /* Don't count the chars from 'showbreak'. */
            csize -= head;
# endif
            col -= csize;
        }

#ifdef FEAT_VIRTUALEDIT
        if (virtual_active()
                && addspaces
                && ((col != wcol && col != wcol + 1) || csize > 1))
        {
            /* 'virtualedit' is set: The difference between wcol and col is
             * filled with spaces. */

            if (line[idx] == NUL)
            {
                /* Append spaces */
                int     correct = wcol - col;
                char_u  *newline = alloc(idx + correct + 1);
                int     t;

                if (newline == NULL)
                    return FAIL;

                for (t = 0; t < idx; ++t)
                    newline[t] = line[t];

                for (t = 0; t < correct; ++t)
                    newline[t + idx] = ' ';

                newline[idx + correct] = NUL;

                ml_replace(pos->lnum, newline, FALSE);
                changed_bytes(pos->lnum, (colnr_T)idx);
                idx += correct;
                col = wcol;
            }
            else
            {
                /* Break a tab */
                int     linelen = (int)STRLEN(line);
                int     correct = wcol - col - csize + 1; /* negative!! */
                char_u  *newline;
                int     t, s = 0;
                int     v;

                if (-correct > csize)
                    return FAIL;

                newline = alloc(linelen + csize);
                if (newline == NULL)
                    return FAIL;

                for (t = 0; t < linelen; t++)
                {
                    if (t != idx)
                        newline[s++] = line[t];
                    else
                        for (v = 0; v < csize; v++)
                            newline[s++] = ' ';
                }

                newline[linelen + csize - 1] = NUL;

                ml_replace(pos->lnum, newline, FALSE);
                changed_bytes(pos->lnum, idx);
                idx += (csize - 1 + correct);
                col += correct;
            }
        }
#endif
    }

    if (idx < 0)
        pos->col = 0;
    else
        pos->col = idx;

#ifdef FEAT_VIRTUALEDIT
    pos->coladd = 0;

    if (finetune)
    {
        if (wcol == MAXCOL)
        {
            /* The width of the last character is used to set coladd. */
            if (!one_more)
            {
                colnr_T     scol, ecol;

                getvcol(curwin, pos, &scol, NULL, &ecol);
                pos->coladd = ecol - scol;
            }
        }
        else
        {
            int b = (int)wcol - (int)col;

            /* The difference between wcol and col is used to set coladd. */
            if (b > 0 && b < (MAXCOL - 2 * W_WIDTH(curwin)))
                pos->coladd = b;

            col += b;
        }
    }
#endif

#ifdef FEAT_MBYTE
    /* prevent from moving onto a trail byte */
    if (has_mbyte)
        mb_adjustpos(pos);
#endif

    if (col < wcol)
        return FAIL;
    return OK;
}

/*
 * Increment the cursor position.  See inc() for return values.
 */
    int
inc_cursor()
{
    return inc(&curwin->w_cursor);
}

/*
 * Increment the line pointer "lp" crossing line boundaries as necessary.
 * Return 1 when going to the next line.
 * Return 2 when moving forward onto a NUL at the end of the line).
 * Return -1 when at the end of file.
 * Return 0 otherwise.
 */
    int
inc(lp)
    pos_T  *lp;
{
    char_u  *p = ml_get_pos(lp);

    if (*p != NUL)      /* still within line, move to next char (may be NUL) */
    {
#ifdef FEAT_MBYTE
        if (has_mbyte)
        {
            int l = (*mb_ptr2len)(p);

            lp->col += l;
            return ((p[l] != NUL) ? 0 : 2);
        }
#endif
        lp->col++;
#ifdef FEAT_VIRTUALEDIT
        lp->coladd = 0;
#endif
        return ((p[1] != NUL) ? 0 : 2);
    }
    if (lp->lnum != curbuf->b_ml.ml_line_count)     /* there is a next line */
    {
        lp->col = 0;
        lp->lnum++;
#ifdef FEAT_VIRTUALEDIT
        lp->coladd = 0;
#endif
        return 1;
    }
    return -1;
}

/*
 * incl(lp): same as inc(), but skip the NUL at the end of non-empty lines
 */
    int
incl(lp)
    pos_T    *lp;
{
    int     r;

    if ((r = inc(lp)) >= 1 && lp->col)
        r = inc(lp);
    return r;
}

/*
 * dec(p)
 *
 * Decrement the line pointer 'p' crossing line boundaries as necessary.
 * Return 1 when crossing a line, -1 when at start of file, 0 otherwise.
 */
    int
dec_cursor()
{
    return dec(&curwin->w_cursor);
}

    int
dec(lp)
    pos_T  *lp;
{
    char_u      *p;

#ifdef FEAT_VIRTUALEDIT
    lp->coladd = 0;
#endif
    if (lp->col > 0)            /* still within line */
    {
        lp->col--;
#ifdef FEAT_MBYTE
        if (has_mbyte)
        {
            p = ml_get(lp->lnum);
            lp->col -= (*mb_head_off)(p, p + lp->col);
        }
#endif
        return 0;
    }
    if (lp->lnum > 1)           /* there is a prior line */
    {
        lp->lnum--;
        p = ml_get(lp->lnum);
        lp->col = (colnr_T)STRLEN(p);
#ifdef FEAT_MBYTE
        if (has_mbyte)
            lp->col -= (*mb_head_off)(p, p + lp->col);
#endif
        return 1;
    }
    return -1;                  /* at start of file */
}

/*
 * decl(lp): same as dec(), but skip the NUL at the end of non-empty lines
 */
    int
decl(lp)
    pos_T    *lp;
{
    int     r;

    if ((r = dec(lp)) == 1 && lp->col)
        r = dec(lp);
    return r;
}

/*
 * Get the line number relative to the current cursor position, i.e. the
 * difference between line number and cursor position. Only look for lines that
 * can be visible, folded lines don't count.
 */
    linenr_T
get_cursor_rel_lnum(wp, lnum)
    win_T       *wp;
    linenr_T    lnum;               /* line number to get the result for */
{
    linenr_T    cursor = wp->w_cursor.lnum;
    linenr_T    retval = 0;

#ifdef FEAT_FOLDING
    if (hasAnyFolding(wp))
    {
        if (lnum > cursor)
        {
            while (lnum > cursor)
            {
                (void)hasFolding(lnum, &lnum, NULL);
                /* if lnum and cursor are in the same fold,
                 * now lnum <= cursor */
                if (lnum > cursor)
                    retval++;
                lnum--;
            }
        }
        else if (lnum < cursor)
        {
            while (lnum < cursor)
            {
                (void)hasFolding(lnum, NULL, &lnum);
                /* if lnum and cursor are in the same fold,
                 * now lnum >= cursor */
                if (lnum < cursor)
                    retval--;
                lnum++;
            }
        }
        /* else if (lnum == cursor)
         *     retval = 0;
         */
    }
    else
#endif
        retval = lnum - cursor;

    return retval;
}

/*
 * Make sure curwin->w_cursor.lnum is valid.
 */
    void
check_cursor_lnum()
{
    if (curwin->w_cursor.lnum > curbuf->b_ml.ml_line_count)
    {
#ifdef FEAT_FOLDING
        /* If there is a closed fold at the end of the file, put the cursor in
         * its first line.  Otherwise in the last line. */
        if (!hasFolding(curbuf->b_ml.ml_line_count,
                                                &curwin->w_cursor.lnum, NULL))
#endif
            curwin->w_cursor.lnum = curbuf->b_ml.ml_line_count;
    }
    if (curwin->w_cursor.lnum <= 0)
        curwin->w_cursor.lnum = 1;
}

/*
 * Make sure curwin->w_cursor.col is valid.
 */
    void
check_cursor_col()
{
    colnr_T len;
#ifdef FEAT_VIRTUALEDIT
    colnr_T oldcol = curwin->w_cursor.col;
    colnr_T oldcoladd = curwin->w_cursor.col + curwin->w_cursor.coladd;
#endif

    len = (colnr_T)STRLEN(ml_get_curline());
    if (len == 0)
        curwin->w_cursor.col = 0;
    else if (curwin->w_cursor.col >= len)
    {
        /* Allow cursor past end-of-line when:
         * - in Insert mode or restarting Insert mode
         * - in Visual mode and 'selection' isn't "old"
         * - 'virtualedit' is set */
        if ((State & INSERT) || restart_edit
#ifdef FEAT_VISUAL
                || (VIsual_active && *p_sel != 'o')
#endif
#ifdef FEAT_VIRTUALEDIT
                || (ve_flags & VE_ONEMORE)
#endif
                || virtual_active())
            curwin->w_cursor.col = len;
        else
        {
            curwin->w_cursor.col = len - 1;
#ifdef FEAT_MBYTE
            /* prevent cursor from moving on the trail byte */
            if (has_mbyte)
                mb_adjust_cursor();
#endif
        }
    }
    else if (curwin->w_cursor.col < 0)
        curwin->w_cursor.col = 0;

#ifdef FEAT_VIRTUALEDIT
    /* If virtual editing is on, we can leave the cursor on the old position,
     * only we must set it to virtual.  But don't do it when at the end of the
     * line. */
    if (oldcol == MAXCOL)
        curwin->w_cursor.coladd = 0;
    else if (ve_flags == VE_ALL)
    {
        if (oldcoladd > curwin->w_cursor.col)
            curwin->w_cursor.coladd = oldcoladd - curwin->w_cursor.col;
        else
            /* avoid weird number when there is a miscalculation or overflow */
            curwin->w_cursor.coladd = 0;
    }
#endif
}

/*
 * make sure curwin->w_cursor in on a valid character
 */
    void
check_cursor()
{
    check_cursor_lnum();
    check_cursor_col();
}

#if defined(FEAT_TEXTOBJ) || defined(PROTO)
/*
 * Make sure curwin->w_cursor is not on the NUL at the end of the line.
 * Allow it when in Visual mode and 'selection' is not "old".
 */
    void
adjust_cursor_col()
{
    if (curwin->w_cursor.col > 0
# ifdef FEAT_VISUAL
            && (!VIsual_active || *p_sel == 'o')
# endif
            && gchar_cursor() == NUL)
        --curwin->w_cursor.col;
}
#endif

/*
 * When curwin->w_leftcol has changed, adjust the cursor position.
 * Return TRUE if the cursor was moved.
 */
    int
leftcol_changed()
{
    long        lastcol;
    colnr_T     s, e;
    int         retval = FALSE;

    changed_cline_bef_curs();
    lastcol = curwin->w_leftcol + W_WIDTH(curwin) - curwin_col_off() - 1;
    validate_virtcol();

    /*
     * If the cursor is right or left of the screen, move it to last or first
     * character.
     */
    if (curwin->w_virtcol > (colnr_T)(lastcol - p_siso))
    {
        retval = TRUE;
        coladvance((colnr_T)(lastcol - p_siso));
    }
    else if (curwin->w_virtcol < curwin->w_leftcol + p_siso)
    {
        retval = TRUE;
        (void)coladvance((colnr_T)(curwin->w_leftcol + p_siso));
    }

    /*
     * If the start of the character under the cursor is not on the screen,
     * advance the cursor one more char.  If this fails (last char of the
     * line) adjust the scrolling.
     */
    getvvcol(curwin, &curwin->w_cursor, &s, NULL, &e);
    if (e > (colnr_T)lastcol)
    {
        retval = TRUE;
        coladvance(s - 1);
    }
    else if (s < curwin->w_leftcol)
    {
        retval = TRUE;
        if (coladvance(e + 1) == FAIL)  /* there isn't another character */
        {
            curwin->w_leftcol = s;      /* adjust w_leftcol instead */
            changed_cline_bef_curs();
        }
    }

    if (retval)
        curwin->w_set_curswant = TRUE;
    redraw_later(NOT_VALID);
    return retval;
}

/**********************************************************************
 * Various routines dealing with allocation and deallocation of memory.
 */

#if defined(MEM_PROFILE) || defined(PROTO)

# define MEM_SIZES  8200
static long_u mem_allocs[MEM_SIZES];
static long_u mem_frees[MEM_SIZES];
static long_u mem_allocated;
static long_u mem_freed;
static long_u mem_peak;
static long_u num_alloc;
static long_u num_freed;

static void mem_pre_alloc_s __ARGS((size_t *sizep));
static void mem_pre_alloc_l __ARGS((long_u *sizep));
static void mem_post_alloc __ARGS((void **pp, size_t size));
static void mem_pre_free __ARGS((void **pp));

    static void
mem_pre_alloc_s(sizep)
    size_t *sizep;
{
    *sizep += sizeof(size_t);
}

    static void
mem_pre_alloc_l(sizep)
    long_u *sizep;
{
    *sizep += sizeof(size_t);
}

    static void
mem_post_alloc(pp, size)
    void **pp;
    size_t size;
{
    if (*pp == NULL)
        return;
    size -= sizeof(size_t);
    *(long_u *)*pp = size;
    if (size <= MEM_SIZES-1)
        mem_allocs[size-1]++;
    else
        mem_allocs[MEM_SIZES-1]++;
    mem_allocated += size;
    if (mem_allocated - mem_freed > mem_peak)
        mem_peak = mem_allocated - mem_freed;
    num_alloc++;
    *pp = (void *)((char *)*pp + sizeof(size_t));
}

    static void
mem_pre_free(pp)
    void **pp;
{
    long_u size;

    *pp = (void *)((char *)*pp - sizeof(size_t));
    size = *(size_t *)*pp;
    if (size <= MEM_SIZES-1)
        mem_frees[size-1]++;
    else
        mem_frees[MEM_SIZES-1]++;
    mem_freed += size;
    num_freed++;
}

/*
 * called on exit via atexit()
 */
    void
vim_mem_profile_dump()
{
    int i, j;

    printf("\r\n");
    j = 0;
    for (i = 0; i < MEM_SIZES - 1; i++)
    {
        if (mem_allocs[i] || mem_frees[i])
        {
            if (mem_frees[i] > mem_allocs[i])
                printf("\r\n%s", _("ERROR: "));
            printf("[%4d / %4lu-%-4lu] ", i + 1, mem_allocs[i], mem_frees[i]);
            j++;
            if (j > 3)
            {
                j = 0;
                printf("\r\n");
            }
        }
    }

    i = MEM_SIZES - 1;
    if (mem_allocs[i])
    {
        printf("\r\n");
        if (mem_frees[i] > mem_allocs[i])
            printf(_("ERROR: "));
        printf("[>%d / %4lu-%-4lu]", i, mem_allocs[i], mem_frees[i]);
    }

    printf(_("\n[bytes] total alloc-freed %lu-%lu, in use %lu, peak use %lu\n"),
            mem_allocated, mem_freed, mem_allocated - mem_freed, mem_peak);
    printf(_("[calls] total re/malloc()'s %lu, total free()'s %lu\n\n"),
            num_alloc, num_freed);
}

#endif /* MEM_PROFILE */

/*
 * Some memory is reserved for error messages and for being able to
 * call mf_release_all(), which needs some memory for mf_trans_add().
 */
#if defined(MSDOS) && !defined(DJGPP)
# define SMALL_MEM
# define KEEP_ROOM 8192L
#else
# define KEEP_ROOM (2 * 8192L)
#endif

/*
 * Note: if unsigned is 16 bits we can only allocate up to 64K with alloc().
 * Use lalloc for larger blocks.
 */
    char_u *
alloc(size)
    unsigned        size;
{
    return (lalloc((long_u)size, TRUE));
}

/*
 * Allocate memory and set all bytes to zero.
 */
    char_u *
alloc_clear(size)
    unsigned        size;
{
    char_u *p;

    p = (lalloc((long_u)size, TRUE));
    if (p != NULL)
        (void)vim_memset(p, 0, (size_t)size);
    return p;
}

/*
 * alloc() with check for maximum line length
 */
    char_u *
alloc_check(size)
    unsigned        size;
{
#if !defined(UNIX) && !defined(__EMX__)
    if (sizeof(int) == 2 && size > 0x7fff)
    {
        /* Don't hide this message */
        emsg_silent = 0;
        EMSG(_("E340: Line is becoming too long"));
        return NULL;
    }
#endif
    return (lalloc((long_u)size, TRUE));
}

/*
 * Allocate memory like lalloc() and set all bytes to zero.
 */
    char_u *
lalloc_clear(size, message)
    long_u      size;
    int         message;
{
    char_u *p;

    p = (lalloc(size, message));
    if (p != NULL)
        (void)vim_memset(p, 0, (size_t)size);
    return p;
}

/*
 * Low level memory allocation function.
 * This is used often, KEEP IT FAST!
 */
    char_u *
lalloc(size, message)
    long_u      size;
    int         message;
{
    char_u      *p;                 /* pointer to new storage space */
    static int  releasing = FALSE;  /* don't do mf_release_all() recursive */
    int         try_again;
#if defined(HAVE_AVAIL_MEM) && !defined(SMALL_MEM)
    static long_u allocated = 0;    /* allocated since last avail check */
#endif

    /* Safety check for allocating zero bytes */
    if (size == 0)
    {
        /* Don't hide this message */
        emsg_silent = 0;
        EMSGN(_("E341: Internal error: lalloc(%ld, )"), size);
        return NULL;
    }

#ifdef MEM_PROFILE
    mem_pre_alloc_l(&size);
#endif

#if defined(MSDOS) && !defined(DJGPP)
    if (size >= 0xfff0)         /* in MSDOS we can't deal with >64K blocks */
        p = NULL;
    else
#endif

    /*
     * Loop when out of memory: Try to release some memfile blocks and
     * if some blocks are released call malloc again.
     */
    for (;;)
    {
        /*
         * Handle three kind of systems:
         * 1. No check for available memory: Just return.
         * 2. Slow check for available memory: call mch_avail_mem() after
         *    allocating KEEP_ROOM amount of memory.
         * 3. Strict check for available memory: call mch_avail_mem()
         */
        if ((p = (char_u *)malloc((size_t)size)) != NULL)
        {
#ifndef HAVE_AVAIL_MEM
            /* 1. No check for available memory: Just return. */
            goto theend;
#else
# ifndef SMALL_MEM
            /* 2. Slow check for available memory: call mch_avail_mem() after
             *    allocating (KEEP_ROOM / 2) amount of memory. */
            allocated += size;
            if (allocated < KEEP_ROOM / 2)
                goto theend;
            allocated = 0;
# endif
            /* 3. check for available memory: call mch_avail_mem() */
            if (mch_avail_mem(TRUE) < KEEP_ROOM && !releasing)
            {
                free((char *)p);        /* System is low... no go! */
                p = NULL;
            }
            else
                goto theend;
#endif
        }
        /*
         * Remember that mf_release_all() is being called to avoid an endless
         * loop, because mf_release_all() may call alloc() recursively.
         */
        if (releasing)
            break;
        releasing = TRUE;

        clear_sb_text();              /* free any scrollback text */
        try_again = mf_release_all(); /* release as many blocks as possible */
#ifdef FEAT_EVAL
        try_again |= garbage_collect(); /* cleanup recursive lists/dicts */
#endif

        releasing = FALSE;
        if (!try_again)
            break;
    }

    if (message && p == NULL)
        do_outofmem_msg(size);

theend:
#ifdef MEM_PROFILE
    mem_post_alloc((void **)&p, (size_t)size);
#endif
    return p;
}

#if defined(MEM_PROFILE) || defined(PROTO)
/*
 * realloc() with memory profiling.
 */
    void *
mem_realloc(ptr, size)
    void *ptr;
    size_t size;
{
    void *p;

    mem_pre_free(&ptr);
    mem_pre_alloc_s(&size);

    p = realloc(ptr, size);

    mem_post_alloc(&p, size);

    return p;
}
#endif

/*
* Avoid repeating the error message many times (they take 1 second each).
* Did_outofmem_msg is reset when a character is read.
*/
    void
do_outofmem_msg(size)
    long_u      size;
{
    if (!did_outofmem_msg)
    {
        /* Don't hide this message */
        emsg_silent = 0;
        EMSGN(_("E342: Out of memory!  (allocating %lu bytes)"), size);
        did_outofmem_msg = TRUE;
    }
}

#if defined(EXITFREE) || defined(PROTO)

# if defined(FEAT_SEARCHPATH)
static void free_findfile __ARGS((void));
# endif

/*
 * Free everything that we allocated.
 * Can be used to detect memory leaks, e.g., with ccmalloc.
 * NOTE: This is tricky!  Things are freed that functions depend on.  Don't be
 * surprised if Vim crashes...
 * Some things can't be freed, esp. things local to a library function.
 */
    void
free_all_mem()
{
    buf_T       *buf, *nextbuf;
    static int  entered = FALSE;

    /* When we cause a crash here it is caught and Vim tries to exit cleanly.
     * Don't try freeing everything again. */
    if (entered)
        return;
    entered = TRUE;

# ifdef FEAT_AUTOCMD
    block_autocmds();       /* don't want to trigger autocommands here */
# endif

# ifdef FEAT_WINDOWS
    /* close all tabs and windows */
    if (first_tabpage->tp_next != NULL)
        do_cmdline_cmd((char_u *)"tabonly!");
    if (firstwin != lastwin)
        do_cmdline_cmd((char_u *)"only!");
# endif

# if defined(FEAT_SPELL)
    /* Free all spell info. */
    spell_free_all();
# endif

# if defined(FEAT_USR_CMDS)
    /* Clear user commands (before deleting buffers). */
    ex_comclear(NULL);
# endif

# ifdef FEAT_MENU
    /* Clear menus. */
    do_cmdline_cmd((char_u *)"aunmenu *");
#  ifdef FEAT_MULTI_LANG
    do_cmdline_cmd((char_u *)"menutranslate clear");
#  endif
# endif

    /* Clear mappings, abbreviations, breakpoints. */
    do_cmdline_cmd((char_u *)"lmapclear");
    do_cmdline_cmd((char_u *)"xmapclear");
    do_cmdline_cmd((char_u *)"mapclear");
    do_cmdline_cmd((char_u *)"mapclear!");
    do_cmdline_cmd((char_u *)"abclear");
# if defined(FEAT_EVAL)
    do_cmdline_cmd((char_u *)"breakdel *");
# endif
# if defined(FEAT_PROFILE)
    do_cmdline_cmd((char_u *)"profdel *");
# endif
# if defined(FEAT_KEYMAP)
    do_cmdline_cmd((char_u *)"set keymap=");
#endif

# ifdef FEAT_TITLE
    free_titles();
# endif
# if defined(FEAT_SEARCHPATH)
    free_findfile();
# endif

    /* Obviously named calls. */
# if defined(FEAT_AUTOCMD)
    free_all_autocmds();
# endif
    clear_termcodes();
    free_all_options();
    free_all_marks();
    alist_clear(&global_alist);
    free_homedir();
    free_search_patterns();
    free_old_sub();
    free_last_insert();
    free_prev_shellcmd();
    free_regexp_stuff();
    free_tag_stuff();
    free_cd_dir();
# ifdef FEAT_SIGNS
    free_signs();
# endif
# ifdef FEAT_EVAL
    set_expr_line(NULL);
# endif
# ifdef FEAT_DIFF
    diff_clear(curtab);
# endif
    clear_sb_text();          /* free any scrollback text */

    /* Free some global vars. */
    vim_free(username);
# ifdef FEAT_CLIPBOARD
    vim_free(clip_exclude_prog);
# endif
    vim_free(last_cmdline);
# ifdef FEAT_CMDHIST
    vim_free(new_last_cmdline);
# endif
    set_keep_msg(NULL, 0);
    vim_free(ff_expand_buffer);

    /* Clear cmdline history. */
    p_hi = 0;
# ifdef FEAT_CMDHIST
    init_history();
# endif

#ifdef FEAT_QUICKFIX
    {
        win_T       *win;
        tabpage_T   *tab;

        qf_free_all(NULL);
        /* Free all location lists */
        FOR_ALL_TAB_WINDOWS(tab, win)
            qf_free_all(win);
    }
#endif

    /* Close all script inputs. */
    close_all_scripts();

#if defined(FEAT_WINDOWS)
    /* Destroy all windows.  Must come before freeing buffers. */
    win_free_all();
#endif

    /* Free all buffers.  Reset 'autochdir' to avoid accessing things that
     * were freed already. */
#ifdef FEAT_AUTOCHDIR
    p_acd = FALSE;
#endif
    for (buf = firstbuf; buf != NULL; )
    {
        nextbuf = buf->b_next;
        close_buffer(NULL, buf, DOBUF_WIPE);
        if (buf_valid(buf))
            buf = nextbuf;      /* didn't work, try next one */
        else
            buf = firstbuf;
    }

#ifdef FEAT_ARABIC
    free_cmdline_buf();
#endif

    /* Clear registers. */
    clear_registers();
    ResetRedobuff();
    ResetRedobuff();

#if defined(FEAT_CLIENTSERVER) && defined(FEAT_X11)
    vim_free(serverDelayedStartName);
#endif

    /* highlight info */
    free_highlight();

    reset_last_sourcing();

#ifdef FEAT_WINDOWS
    free_tabpage(first_tabpage);
    first_tabpage = NULL;
#endif

# ifdef UNIX
    /* Machine-specific free. */
    mch_free_mem();
# endif

    /* message history */
    for (;;)
        if (delete_first_msg() == FAIL)
            break;

# ifdef FEAT_EVAL
    eval_clear();
# endif

    free_termoptions();

    /* screenlines (can't display anything now!) */
    free_screenlines();

#if defined(USE_XSMP)
    xsmp_close();
#endif
#ifdef FEAT_GUI_GTK
    gui_mch_free_all();
#endif
    clear_hl_tables();

    vim_free(IObuff);
    vim_free(NameBuff);
}
#endif

/*
 * copy a string into newly allocated memory
 */
    char_u *
vim_strsave(string)
    char_u      *string;
{
    char_u      *p;
    unsigned    len;

    len = (unsigned)STRLEN(string) + 1;
    p = alloc(len);
    if (p != NULL)
        mch_memmove(p, string, (size_t)len);
    return p;
}

    char_u *
vim_strnsave(string, len)
    char_u      *string;
    int         len;
{
    char_u      *p;

    p = alloc((unsigned)(len + 1));
    if (p != NULL)
    {
        STRNCPY(p, string, len);
        p[len] = NUL;
    }
    return p;
}

/*
 * Same as vim_strsave(), but any characters found in esc_chars are preceded
 * by a backslash.
 */
    char_u *
vim_strsave_escaped(string, esc_chars)
    char_u      *string;
    char_u      *esc_chars;
{
    return vim_strsave_escaped_ext(string, esc_chars, '\\', FALSE);
}

/*
 * Same as vim_strsave_escaped(), but when "bsl" is TRUE also escape
 * characters where rem_backslash() would remove the backslash.
 * Escape the characters with "cc".
 */
    char_u *
vim_strsave_escaped_ext(string, esc_chars, cc, bsl)
    char_u      *string;
    char_u      *esc_chars;
    int         cc;
    int         bsl;
{
    char_u      *p;
    char_u      *p2;
    char_u      *escaped_string;
    unsigned    length;
#ifdef FEAT_MBYTE
    int         l;
#endif

    /*
     * First count the number of backslashes required.
     * Then allocate the memory and insert them.
     */
    length = 1;                         /* count the trailing NUL */
    for (p = string; *p; p++)
    {
#ifdef FEAT_MBYTE
        if (has_mbyte && (l = (*mb_ptr2len)(p)) > 1)
        {
            length += l;                /* count a multibyte char */
            p += l - 1;
            continue;
        }
#endif
        if (vim_strchr(esc_chars, *p) != NULL || (bsl && rem_backslash(p)))
            ++length;                   /* count a backslash */
        ++length;                       /* count an ordinary char */
    }
    escaped_string = alloc(length);
    if (escaped_string != NULL)
    {
        p2 = escaped_string;
        for (p = string; *p; p++)
        {
#ifdef FEAT_MBYTE
            if (has_mbyte && (l = (*mb_ptr2len)(p)) > 1)
            {
                mch_memmove(p2, p, (size_t)l);
                p2 += l;
                p += l - 1;             /* skip multibyte char  */
                continue;
            }
#endif
            if (vim_strchr(esc_chars, *p) != NULL || (bsl && rem_backslash(p)))
                *p2++ = cc;
            *p2++ = *p;
        }
        *p2 = NUL;
    }
    return escaped_string;
}

/*
 * Return TRUE when 'shell' has "csh" in the tail.
 */
    int
csh_like_shell()
{
    return (strstr((char *)gettail(p_sh), "csh") != NULL);
}

/*
 * Escape "string" for use as a shell argument with system().
 * This uses single quotes, except when we know we need to use double quotes
 * (MS-DOS and MS-Windows without 'shellslash' set).
 * Escape a newline, depending on the 'shell' option.
 * When "do_special" is TRUE also replace "!", "%", "#" and things starting
 * with "<" like "<cfile>".
 * Returns the result in allocated memory, NULL if we have run out.
 */
    char_u *
vim_strsave_shellescape(string, do_special)
    char_u      *string;
    int         do_special;
{
    unsigned    length;
    char_u      *p;
    char_u      *d;
    char_u      *escaped_string;
    int         l;
    int         csh_like;

    /* Only csh and similar shells expand '!' within single quotes.  For sh and
     * the like we must not put a backslash before it, it will be taken
     * literally.  If do_special is set the '!' will be escaped twice.
     * Csh also needs to have "\n" escaped twice when do_special is set. */
    csh_like = csh_like_shell();

    /* First count the number of extra bytes required. */
    length = (unsigned)STRLEN(string) + 3;  /* two quotes and a trailing NUL */
    for (p = string; *p != NUL; mb_ptr_adv(p))
    {
# if defined(WIN32) || defined(WIN16) || defined(DOS)
        if (!p_ssl)
        {
            if (*p == '"')
                ++length;               /* " -> "" */
        }
        else
# endif
        if (*p == '\'')
            length += 3;                /* ' => '\'' */
        if (*p == '\n' || (*p == '!' && (csh_like || do_special)))
        {
            ++length;                   /* insert backslash */
            if (csh_like && do_special)
                ++length;               /* insert backslash */
        }
        if (do_special && find_cmdline_var(p, &l) >= 0)
        {
            ++length;                   /* insert backslash */
            p += l - 1;
        }
    }

    /* Allocate memory for the result and fill it. */
    escaped_string = alloc(length);
    if (escaped_string != NULL)
    {
        d = escaped_string;

        /* add opening quote */
# if defined(WIN32) || defined(WIN16) || defined(DOS)
        if (!p_ssl)
            *d++ = '"';
        else
# endif
            *d++ = '\'';

        for (p = string; *p != NUL; )
        {
# if defined(WIN32) || defined(WIN16) || defined(DOS)
            if (!p_ssl)
            {
                if (*p == '"')
                {
                    *d++ = '"';
                    *d++ = '"';
                    ++p;
                    continue;
                }
            }
            else
# endif
            if (*p == '\'')
            {
                *d++ = '\'';
                *d++ = '\\';
                *d++ = '\'';
                *d++ = '\'';
                ++p;
                continue;
            }
            if (*p == '\n' || (*p == '!' && (csh_like || do_special)))
            {
                *d++ = '\\';
                if (csh_like && do_special)
                    *d++ = '\\';
                *d++ = *p++;
                continue;
            }
            if (do_special && find_cmdline_var(p, &l) >= 0)
            {
                *d++ = '\\';            /* insert backslash */
                while (--l >= 0)        /* copy the var */
                    *d++ = *p++;
                continue;
            }

            MB_COPY_CHAR(p, d);
        }

        /* add terminating quote and finish with a NUL */
# if defined(WIN32) || defined(WIN16) || defined(DOS)
        if (!p_ssl)
            *d++ = '"';
        else
# endif
            *d++ = '\'';
        *d = NUL;
    }

    return escaped_string;
}

/*
 * Like vim_strsave(), but make all characters uppercase.
 * This uses ASCII lower-to-upper case translation, language independent.
 */
    char_u *
vim_strsave_up(string)
    char_u      *string;
{
    char_u *p1;

    p1 = vim_strsave(string);
    vim_strup(p1);
    return p1;
}

/*
 * Like vim_strnsave(), but make all characters uppercase.
 * This uses ASCII lower-to-upper case translation, language independent.
 */
    char_u *
vim_strnsave_up(string, len)
    char_u      *string;
    int         len;
{
    char_u *p1;

    p1 = vim_strnsave(string, len);
    vim_strup(p1);
    return p1;
}

/*
 * ASCII lower-to-upper case translation, language independent.
 */
    void
vim_strup(p)
    char_u      *p;
{
    char_u  *p2;
    int     c;

    if (p != NULL)
    {
        p2 = p;
        while ((c = *p2) != NUL)
#ifdef EBCDIC
            *p2++ = isalpha(c) ? toupper(c) : c;
#else
            *p2++ = (c < 'a' || c > 'z') ? c : (c - 0x20);
#endif
    }
}

#if defined(FEAT_EVAL) || defined(FEAT_SPELL) || defined(PROTO)
/*
 * Make string "s" all upper-case and return it in allocated memory.
 * Handles multi-byte characters as well as possible.
 * Returns NULL when out of memory.
 */
    char_u *
strup_save(orig)
    char_u      *orig;
{
    char_u      *p;
    char_u      *res;

    res = p = vim_strsave(orig);

    if (res != NULL)
        while (*p != NUL)
        {
# ifdef FEAT_MBYTE
            int         l;

            if (enc_utf8)
            {
                int     c, uc;
                int     nl;
                char_u  *s;

                c = utf_ptr2char(p);
                uc = utf_toupper(c);

                /* Reallocate string when byte count changes.  This is rare,
                 * thus it's OK to do another malloc()/free(). */
                l = utf_ptr2len(p);
                nl = utf_char2len(uc);
                if (nl != l)
                {
                    s = alloc((unsigned)STRLEN(res) + 1 + nl - l);
                    if (s == NULL)
                        break;
                    mch_memmove(s, res, p - res);
                    STRCPY(s + (p - res) + nl, p + l);
                    p = s + (p - res);
                    vim_free(res);
                    res = s;
                }

                utf_char2bytes(uc, p);
                p += nl;
            }
            else if (has_mbyte && (l = (*mb_ptr2len)(p)) > 1)
                p += l;         /* skip multi-byte character */
            else
# endif
            {
                *p = TOUPPER_LOC(*p); /* note that toupper() can be a macro */
                p++;
            }
        }

    return res;
}
#endif

/*
 * copy a space a number of times
 */
    void
copy_spaces(ptr, count)
    char_u      *ptr;
    size_t      count;
{
    size_t      i = count;
    char_u      *p = ptr;

    while (i--)
        *p++ = ' ';
}

#if defined(FEAT_VISUALEXTRA) || defined(PROTO)
/*
 * Copy a character a number of times.
 * Does not work for multi-byte characters!
 */
    void
copy_chars(ptr, count, c)
    char_u      *ptr;
    size_t      count;
    int         c;
{
    size_t      i = count;
    char_u      *p = ptr;

    while (i--)
        *p++ = c;
}
#endif

/*
 * delete spaces at the end of a string
 */
    void
del_trailing_spaces(ptr)
    char_u      *ptr;
{
    char_u      *q;

    q = ptr + STRLEN(ptr);
    while (--q > ptr && vim_iswhite(q[0]) && q[-1] != '\\' && q[-1] != Ctrl_V)
        *q = NUL;
}

/*
 * Like strncpy(), but always terminate the result with one NUL.
 * "to" must be "len + 1" long!
 */
    void
vim_strncpy(to, from, len)
    char_u      *to;
    char_u      *from;
    size_t      len;
{
    STRNCPY(to, from, len);
    to[len] = NUL;
}

/*
 * Isolate one part of a string option where parts are separated with
 * "sep_chars".
 * The part is copied into "buf[maxlen]".
 * "*option" is advanced to the next part.
 * The length is returned.
 */
    int
copy_option_part(option, buf, maxlen, sep_chars)
    char_u      **option;
    char_u      *buf;
    int         maxlen;
    char        *sep_chars;
{
    int     len = 0;
    char_u  *p = *option;

    /* skip '.' at start of option part, for 'suffixes' */
    if (*p == '.')
        buf[len++] = *p++;
    while (*p != NUL && vim_strchr((char_u *)sep_chars, *p) == NULL)
    {
        /*
         * Skip backslash before a separator character and space.
         */
        if (p[0] == '\\' && vim_strchr((char_u *)sep_chars, p[1]) != NULL)
            ++p;
        if (len < maxlen - 1)
            buf[len++] = *p;
        ++p;
    }
    buf[len] = NUL;

    if (*p != NUL && *p != ',') /* skip non-standard separator */
        ++p;
    p = skip_to_option_part(p); /* p points to next file name */

    *option = p;
    return len;
}

/*
 * Replacement for free() that ignores NULL pointers.
 * Also skip free() when exiting for sure, this helps when we caught a deadly
 * signal that was caused by a crash in free().
 */
    void
vim_free(x)
    void *x;
{
    if (x != NULL && !really_exiting)
    {
#ifdef MEM_PROFILE
        mem_pre_free(&x);
#endif
        free(x);
    }
}

#ifndef HAVE_MEMSET
    void *
vim_memset(ptr, c, size)
    void    *ptr;
    int     c;
    size_t  size;
{
    char *p = ptr;

    while (size-- > 0)
        *p++ = c;
    return ptr;
}
#endif

#ifdef VIM_MEMCMP
/*
 * Return zero when "b1" and "b2" are the same for "len" bytes.
 * Return non-zero otherwise.
 */
    int
vim_memcmp(b1, b2, len)
    void    *b1;
    void    *b2;
    size_t  len;
{
    char_u  *p1 = (char_u *)b1, *p2 = (char_u *)b2;

    for ( ; len > 0; --len)
    {
        if (*p1 != *p2)
            return 1;
        ++p1;
        ++p2;
    }
    return 0;
}
#endif

#ifdef VIM_MEMMOVE
/*
 * Version of memmove() that handles overlapping source and destination.
 * For systems that don't have a function that is guaranteed to do that (SYSV).
 */
    void
mch_memmove(dst_arg, src_arg, len)
    void    *src_arg, *dst_arg;
    size_t  len;
{
    /*
     * A void doesn't have a size, we use char pointers.
     */
    char *dst = dst_arg, *src = src_arg;

                                        /* overlap, copy backwards */
    if (dst > src && dst < src + len)
    {
        src += len;
        dst += len;
        while (len-- > 0)
            *--dst = *--src;
    }
    else                                /* copy forwards */
        while (len-- > 0)
            *dst++ = *src++;
}
#endif

#if (!defined(HAVE_STRCASECMP) && !defined(HAVE_STRICMP)) || defined(PROTO)
/*
 * Compare two strings, ignoring case, using current locale.
 * Doesn't work for multi-byte characters.
 * return 0 for match, < 0 for smaller, > 0 for bigger
 */
    int
vim_stricmp(s1, s2)
    char        *s1;
    char        *s2;
{
    int         i;

    for (;;)
    {
        i = (int)TOLOWER_LOC(*s1) - (int)TOLOWER_LOC(*s2);
        if (i != 0)
            return i;                       /* this character different */
        if (*s1 == NUL)
            break;                          /* strings match until NUL */
        ++s1;
        ++s2;
    }
    return 0;                               /* strings match */
}
#endif

#if (!defined(HAVE_STRNCASECMP) && !defined(HAVE_STRNICMP)) || defined(PROTO)
/*
 * Compare two strings, for length "len", ignoring case, using current locale.
 * Doesn't work for multi-byte characters.
 * return 0 for match, < 0 for smaller, > 0 for bigger
 */
    int
vim_strnicmp(s1, s2, len)
    char        *s1;
    char        *s2;
    size_t      len;
{
    int         i;

    while (len > 0)
    {
        i = (int)TOLOWER_LOC(*s1) - (int)TOLOWER_LOC(*s2);
        if (i != 0)
            return i;                       /* this character different */
        if (*s1 == NUL)
            break;                          /* strings match until NUL */
        ++s1;
        ++s2;
        --len;
    }
    return 0;                               /* strings match */
}
#endif

#if 0   /* currently not used */
/*
 * Check if string "s2" appears somewhere in "s1" while ignoring case.
 * Return NULL if not, a pointer to the first occurrence if it does.
 */
    char_u *
vim_stristr(s1, s2)
    char_u      *s1;
    char_u      *s2;
{
    char_u      *p;
    int         len = STRLEN(s2);
    char_u      *end = s1 + STRLEN(s1) - len;

    for (p = s1; p <= end; ++p)
        if (STRNICMP(p, s2, len) == 0)
            return p;
    return NULL;
}
#endif

/*
 * Version of strchr() and strrchr() that handle unsigned char strings
 * with characters from 128 to 255 correctly.  It also doesn't return a
 * pointer to the NUL at the end of the string.
 */
    char_u  *
vim_strchr(string, c)
    char_u      *string;
    int         c;
{
    char_u      *p;
    int         b;

    p = string;
#ifdef FEAT_MBYTE
    if (enc_utf8 && c >= 0x80)
    {
        while (*p != NUL)
        {
            if (utf_ptr2char(p) == c)
                return p;
            p += (*mb_ptr2len)(p);
        }
        return NULL;
    }
    if (enc_dbcs != 0 && c > 255)
    {
        int     n2 = c & 0xff;

        c = ((unsigned)c >> 8) & 0xff;
        while ((b = *p) != NUL)
        {
            if (b == c && p[1] == n2)
                return p;
            p += (*mb_ptr2len)(p);
        }
        return NULL;
    }
    if (has_mbyte)
    {
        while ((b = *p) != NUL)
        {
            if (b == c)
                return p;
            p += (*mb_ptr2len)(p);
        }
        return NULL;
    }
#endif
    while ((b = *p) != NUL)
    {
        if (b == c)
            return p;
        ++p;
    }
    return NULL;
}

/*
 * Version of strchr() that only works for bytes and handles unsigned char
 * strings with characters above 128 correctly. It also doesn't return a
 * pointer to the NUL at the end of the string.
 */
    char_u  *
vim_strbyte(string, c)
    char_u      *string;
    int         c;
{
    char_u      *p = string;

    while (*p != NUL)
    {
        if (*p == c)
            return p;
        ++p;
    }
    return NULL;
}

/*
 * Search for last occurrence of "c" in "string".
 * Return NULL if not found.
 * Does not handle multi-byte char for "c"!
 */
    char_u  *
vim_strrchr(string, c)
    char_u      *string;
    int         c;
{
    char_u      *retval = NULL;
    char_u      *p = string;

    while (*p)
    {
        if (*p == c)
            retval = p;
        mb_ptr_adv(p);
    }
    return retval;
}

/*
 * Vim's version of strpbrk(), in case it's missing.
 * Don't generate a prototype for this, causes problems when it's not used.
 */
#ifndef PROTO
# ifndef HAVE_STRPBRK
#  ifdef vim_strpbrk
#   undef vim_strpbrk
#  endif
    char_u *
vim_strpbrk(s, charset)
    char_u      *s;
    char_u      *charset;
{
    while (*s)
    {
        if (vim_strchr(charset, *s) != NULL)
            return s;
        mb_ptr_adv(s);
    }
    return NULL;
}
# endif
#endif

/*
 * Vim has its own isspace() function, because on some machines isspace()
 * can't handle characters above 128.
 */
    int
vim_isspace(x)
    int     x;
{
    return ((x >= 9 && x <= 13) || x == ' ');
}

/************************************************************************
 * Functions for handling growing arrays.
 */

/*
 * Clear an allocated growing array.
 */
    void
ga_clear(gap)
    garray_T *gap;
{
    vim_free(gap->ga_data);
    ga_init(gap);
}

/*
 * Clear a growing array that contains a list of strings.
 */
    void
ga_clear_strings(gap)
    garray_T *gap;
{
    int         i;

    for (i = 0; i < gap->ga_len; ++i)
        vim_free(((char_u **)(gap->ga_data))[i]);
    ga_clear(gap);
}

/*
 * Initialize a growing array.  Don't forget to set ga_itemsize and
 * ga_growsize!  Or use ga_init2().
 */
    void
ga_init(gap)
    garray_T *gap;
{
    gap->ga_data = NULL;
    gap->ga_maxlen = 0;
    gap->ga_len = 0;
}

    void
ga_init2(gap, itemsize, growsize)
    garray_T    *gap;
    int         itemsize;
    int         growsize;
{
    ga_init(gap);
    gap->ga_itemsize = itemsize;
    gap->ga_growsize = growsize;
}

/*
 * Make room in growing array "gap" for at least "n" items.
 * Return FAIL for failure, OK otherwise.
 */
    int
ga_grow(gap, n)
    garray_T    *gap;
    int         n;
{
    size_t      len;
    char_u      *pp;

    if (gap->ga_maxlen - gap->ga_len < n)
    {
        if (n < gap->ga_growsize)
            n = gap->ga_growsize;
        len = gap->ga_itemsize * (gap->ga_len + n);
        pp = alloc_clear((unsigned)len);
        if (pp == NULL)
            return FAIL;
        gap->ga_maxlen = gap->ga_len + n;
        if (gap->ga_data != NULL)
        {
            mch_memmove(pp, gap->ga_data,
                                      (size_t)(gap->ga_itemsize * gap->ga_len));
            vim_free(gap->ga_data);
        }
        gap->ga_data = pp;
    }
    return OK;
}

/*
 * Concatenate a string to a growarray which contains characters.
 * Note: Does NOT copy the NUL at the end!
 */
    void
ga_concat(gap, s)
    garray_T    *gap;
    char_u      *s;
{
    int    len = (int)STRLEN(s);

    if (ga_grow(gap, len) == OK)
    {
        mch_memmove((char *)gap->ga_data + gap->ga_len, s, (size_t)len);
        gap->ga_len += len;
    }
}

/*
 * Append one byte to a growarray which contains bytes.
 */
    void
ga_append(gap, c)
    garray_T    *gap;
    int         c;
{
    if (ga_grow(gap, 1) == OK)
    {
        *((char *)gap->ga_data + gap->ga_len) = c;
        ++gap->ga_len;
    }
}

/************************************************************************
 * functions that use lookup tables for various things, generally to do with
 * special key codes.
 */

/*
 * Some useful tables.
 */

static struct modmasktable
{
    short       mod_mask;       /* Bit-mask for particular key modifier */
    short       mod_flag;       /* Bit(s) for particular key modifier */
    char_u      name;           /* Single letter name of modifier */
} mod_mask_table[] =
{
    {MOD_MASK_ALT,              MOD_MASK_ALT,           (char_u)'M'},
    {MOD_MASK_META,             MOD_MASK_META,          (char_u)'T'},
    {MOD_MASK_CTRL,             MOD_MASK_CTRL,          (char_u)'C'},
    {MOD_MASK_SHIFT,            MOD_MASK_SHIFT,         (char_u)'S'},
    {MOD_MASK_MULTI_CLICK,      MOD_MASK_2CLICK,        (char_u)'2'},
    {MOD_MASK_MULTI_CLICK,      MOD_MASK_3CLICK,        (char_u)'3'},
    {MOD_MASK_MULTI_CLICK,      MOD_MASK_4CLICK,        (char_u)'4'},
#ifdef MACOS
    {MOD_MASK_CMD,              MOD_MASK_CMD,           (char_u)'D'},
#endif
    /* 'A' must be the last one */
    {MOD_MASK_ALT,              MOD_MASK_ALT,           (char_u)'A'},
    {0, 0, NUL}
};

/*
 * Shifted key terminal codes and their unshifted equivalent.
 * Don't add mouse codes here, they are handled separately!
 */
#define MOD_KEYS_ENTRY_SIZE 5

static char_u modifier_keys_table[] =
{
/*  mod mask        with modifier               without modifier */
    MOD_MASK_SHIFT, '&', '9',                   '@', '1',       /* begin */
    MOD_MASK_SHIFT, '&', '0',                   '@', '2',       /* cancel */
    MOD_MASK_SHIFT, '*', '1',                   '@', '4',       /* command */
    MOD_MASK_SHIFT, '*', '2',                   '@', '5',       /* copy */
    MOD_MASK_SHIFT, '*', '3',                   '@', '6',       /* create */
    MOD_MASK_SHIFT, '*', '4',                   'k', 'D',       /* delete char */
    MOD_MASK_SHIFT, '*', '5',                   'k', 'L',       /* delete line */
    MOD_MASK_SHIFT, '*', '7',                   '@', '7',       /* end */
    MOD_MASK_CTRL,  KS_EXTRA, (int)KE_C_END,    '@', '7',       /* end */
    MOD_MASK_SHIFT, '*', '9',                   '@', '9',       /* exit */
    MOD_MASK_SHIFT, '*', '0',                   '@', '0',       /* find */
    MOD_MASK_SHIFT, '#', '1',                   '%', '1',       /* help */
    MOD_MASK_SHIFT, '#', '2',                   'k', 'h',       /* home */
    MOD_MASK_CTRL,  KS_EXTRA, (int)KE_C_HOME,   'k', 'h',       /* home */
    MOD_MASK_SHIFT, '#', '3',                   'k', 'I',       /* insert */
    MOD_MASK_SHIFT, '#', '4',                   'k', 'l',       /* left arrow */
    MOD_MASK_CTRL,  KS_EXTRA, (int)KE_C_LEFT,   'k', 'l',       /* left arrow */
    MOD_MASK_SHIFT, '%', 'a',                   '%', '3',       /* message */
    MOD_MASK_SHIFT, '%', 'b',                   '%', '4',       /* move */
    MOD_MASK_SHIFT, '%', 'c',                   '%', '5',       /* next */
    MOD_MASK_SHIFT, '%', 'd',                   '%', '7',       /* options */
    MOD_MASK_SHIFT, '%', 'e',                   '%', '8',       /* previous */
    MOD_MASK_SHIFT, '%', 'f',                   '%', '9',       /* print */
    MOD_MASK_SHIFT, '%', 'g',                   '%', '0',       /* redo */
    MOD_MASK_SHIFT, '%', 'h',                   '&', '3',       /* replace */
    MOD_MASK_SHIFT, '%', 'i',                   'k', 'r',       /* right arr. */
    MOD_MASK_CTRL,  KS_EXTRA, (int)KE_C_RIGHT,  'k', 'r',       /* right arr. */
    MOD_MASK_SHIFT, '%', 'j',                   '&', '5',       /* resume */
    MOD_MASK_SHIFT, '!', '1',                   '&', '6',       /* save */
    MOD_MASK_SHIFT, '!', '2',                   '&', '7',       /* suspend */
    MOD_MASK_SHIFT, '!', '3',                   '&', '8',       /* undo */
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_UP,     'k', 'u',       /* up arrow */
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_DOWN,   'k', 'd',       /* down arrow */

                                                                /* vt100 F1 */
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_XF1,    KS_EXTRA, (int)KE_XF1,
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_XF2,    KS_EXTRA, (int)KE_XF2,
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_XF3,    KS_EXTRA, (int)KE_XF3,
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_XF4,    KS_EXTRA, (int)KE_XF4,

    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F1,     'k', '1',       /* F1 */
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F2,     'k', '2',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F3,     'k', '3',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F4,     'k', '4',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F5,     'k', '5',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F6,     'k', '6',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F7,     'k', '7',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F8,     'k', '8',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F9,     'k', '9',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F10,    'k', ';',       /* F10 */

    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F11,    'F', '1',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F12,    'F', '2',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F13,    'F', '3',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F14,    'F', '4',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F15,    'F', '5',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F16,    'F', '6',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F17,    'F', '7',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F18,    'F', '8',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F19,    'F', '9',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F20,    'F', 'A',

    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F21,    'F', 'B',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F22,    'F', 'C',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F23,    'F', 'D',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F24,    'F', 'E',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F25,    'F', 'F',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F26,    'F', 'G',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F27,    'F', 'H',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F28,    'F', 'I',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F29,    'F', 'J',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F30,    'F', 'K',

    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F31,    'F', 'L',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F32,    'F', 'M',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F33,    'F', 'N',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F34,    'F', 'O',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F35,    'F', 'P',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F36,    'F', 'Q',
    MOD_MASK_SHIFT, KS_EXTRA, (int)KE_S_F37,    'F', 'R',

                                                            /* TAB pseudo code*/
    MOD_MASK_SHIFT, 'k', 'B',                   KS_EXTRA, (int)KE_TAB,

    NUL
};

static struct key_name_entry
{
    int     key;        /* Special key code or ascii value */
    char_u  *name;      /* Name of key */
} key_names_table[] =
{
    {' ',               (char_u *)"Space"},
    {TAB,               (char_u *)"Tab"},
    {K_TAB,             (char_u *)"Tab"},
    {NL,                (char_u *)"NL"},
    {NL,                (char_u *)"NewLine"},   /* Alternative name */
    {NL,                (char_u *)"LineFeed"},  /* Alternative name */
    {NL,                (char_u *)"LF"},        /* Alternative name */
    {CAR,               (char_u *)"CR"},
    {CAR,               (char_u *)"Return"},    /* Alternative name */
    {CAR,               (char_u *)"Enter"},     /* Alternative name */
    {K_BS,              (char_u *)"BS"},
    {K_BS,              (char_u *)"BackSpace"}, /* Alternative name */
    {ESC,               (char_u *)"Esc"},
    {CSI,               (char_u *)"CSI"},
    {K_CSI,             (char_u *)"xCSI"},
    {'|',               (char_u *)"Bar"},
    {'\\',              (char_u *)"Bslash"},
    {K_DEL,             (char_u *)"Del"},
    {K_DEL,             (char_u *)"Delete"},    /* Alternative name */
    {K_KDEL,            (char_u *)"kDel"},
    {K_UP,              (char_u *)"Up"},
    {K_DOWN,            (char_u *)"Down"},
    {K_LEFT,            (char_u *)"Left"},
    {K_RIGHT,           (char_u *)"Right"},
    {K_XUP,             (char_u *)"xUp"},
    {K_XDOWN,           (char_u *)"xDown"},
    {K_XLEFT,           (char_u *)"xLeft"},
    {K_XRIGHT,          (char_u *)"xRight"},

    {K_F1,              (char_u *)"F1"},
    {K_F2,              (char_u *)"F2"},
    {K_F3,              (char_u *)"F3"},
    {K_F4,              (char_u *)"F4"},
    {K_F5,              (char_u *)"F5"},
    {K_F6,              (char_u *)"F6"},
    {K_F7,              (char_u *)"F7"},
    {K_F8,              (char_u *)"F8"},
    {K_F9,              (char_u *)"F9"},
    {K_F10,             (char_u *)"F10"},

    {K_F11,             (char_u *)"F11"},
    {K_F12,             (char_u *)"F12"},
    {K_F13,             (char_u *)"F13"},
    {K_F14,             (char_u *)"F14"},
    {K_F15,             (char_u *)"F15"},
    {K_F16,             (char_u *)"F16"},
    {K_F17,             (char_u *)"F17"},
    {K_F18,             (char_u *)"F18"},
    {K_F19,             (char_u *)"F19"},
    {K_F20,             (char_u *)"F20"},

    {K_F21,             (char_u *)"F21"},
    {K_F22,             (char_u *)"F22"},
    {K_F23,             (char_u *)"F23"},
    {K_F24,             (char_u *)"F24"},
    {K_F25,             (char_u *)"F25"},
    {K_F26,             (char_u *)"F26"},
    {K_F27,             (char_u *)"F27"},
    {K_F28,             (char_u *)"F28"},
    {K_F29,             (char_u *)"F29"},
    {K_F30,             (char_u *)"F30"},

    {K_F31,             (char_u *)"F31"},
    {K_F32,             (char_u *)"F32"},
    {K_F33,             (char_u *)"F33"},
    {K_F34,             (char_u *)"F34"},
    {K_F35,             (char_u *)"F35"},
    {K_F36,             (char_u *)"F36"},
    {K_F37,             (char_u *)"F37"},

    {K_XF1,             (char_u *)"xF1"},
    {K_XF2,             (char_u *)"xF2"},
    {K_XF3,             (char_u *)"xF3"},
    {K_XF4,             (char_u *)"xF4"},

    {K_HELP,            (char_u *)"Help"},
    {K_UNDO,            (char_u *)"Undo"},
    {K_INS,             (char_u *)"Insert"},
    {K_INS,             (char_u *)"Ins"},       /* Alternative name */
    {K_KINS,            (char_u *)"kInsert"},
    {K_HOME,            (char_u *)"Home"},
    {K_KHOME,           (char_u *)"kHome"},
    {K_XHOME,           (char_u *)"xHome"},
    {K_ZHOME,           (char_u *)"zHome"},
    {K_END,             (char_u *)"End"},
    {K_KEND,            (char_u *)"kEnd"},
    {K_XEND,            (char_u *)"xEnd"},
    {K_ZEND,            (char_u *)"zEnd"},
    {K_PAGEUP,          (char_u *)"PageUp"},
    {K_PAGEDOWN,        (char_u *)"PageDown"},
    {K_KPAGEUP,         (char_u *)"kPageUp"},
    {K_KPAGEDOWN,       (char_u *)"kPageDown"},

    {K_KPLUS,           (char_u *)"kPlus"},
    {K_KMINUS,          (char_u *)"kMinus"},
    {K_KDIVIDE,         (char_u *)"kDivide"},
    {K_KMULTIPLY,       (char_u *)"kMultiply"},
    {K_KENTER,          (char_u *)"kEnter"},
    {K_KPOINT,          (char_u *)"kPoint"},

    {K_K0,              (char_u *)"k0"},
    {K_K1,              (char_u *)"k1"},
    {K_K2,              (char_u *)"k2"},
    {K_K3,              (char_u *)"k3"},
    {K_K4,              (char_u *)"k4"},
    {K_K5,              (char_u *)"k5"},
    {K_K6,              (char_u *)"k6"},
    {K_K7,              (char_u *)"k7"},
    {K_K8,              (char_u *)"k8"},
    {K_K9,              (char_u *)"k9"},

    {'<',               (char_u *)"lt"},

    {K_MOUSE,           (char_u *)"Mouse"},
    {K_NETTERM_MOUSE,   (char_u *)"NetMouse"},
    {K_DEC_MOUSE,       (char_u *)"DecMouse"},
    {K_JSBTERM_MOUSE,   (char_u *)"JsbMouse"},
    {K_PTERM_MOUSE,     (char_u *)"PtermMouse"},
    {K_LEFTMOUSE,       (char_u *)"LeftMouse"},
    {K_LEFTMOUSE_NM,    (char_u *)"LeftMouseNM"},
    {K_LEFTDRAG,        (char_u *)"LeftDrag"},
    {K_LEFTRELEASE,     (char_u *)"LeftRelease"},
    {K_LEFTRELEASE_NM,  (char_u *)"LeftReleaseNM"},
    {K_MIDDLEMOUSE,     (char_u *)"MiddleMouse"},
    {K_MIDDLEDRAG,      (char_u *)"MiddleDrag"},
    {K_MIDDLERELEASE,   (char_u *)"MiddleRelease"},
    {K_RIGHTMOUSE,      (char_u *)"RightMouse"},
    {K_RIGHTDRAG,       (char_u *)"RightDrag"},
    {K_RIGHTRELEASE,    (char_u *)"RightRelease"},
    {K_MOUSEDOWN,       (char_u *)"MouseDown"},
    {K_MOUSEUP,         (char_u *)"MouseUp"},
    {K_X1MOUSE,         (char_u *)"X1Mouse"},
    {K_X1DRAG,          (char_u *)"X1Drag"},
    {K_X1RELEASE,               (char_u *)"X1Release"},
    {K_X2MOUSE,         (char_u *)"X2Mouse"},
    {K_X2DRAG,          (char_u *)"X2Drag"},
    {K_X2RELEASE,               (char_u *)"X2Release"},
    {K_DROP,            (char_u *)"Drop"},
    {K_ZERO,            (char_u *)"Nul"},
#ifdef FEAT_EVAL
    {K_SNR,             (char_u *)"SNR"},
#endif
    {K_PLUG,            (char_u *)"Plug"},
    {0,                 NULL}
};

#define KEY_NAMES_TABLE_LEN (sizeof(key_names_table) / sizeof(struct key_name_entry))

#ifdef FEAT_MOUSE
static struct mousetable
{
    int     pseudo_code;        /* Code for pseudo mouse event */
    int     button;             /* Which mouse button is it? */
    int     is_click;           /* Is it a mouse button click event? */
    int     is_drag;            /* Is it a mouse drag event? */
} mouse_table[] =
{
    {(int)KE_LEFTMOUSE,         MOUSE_LEFT,     TRUE,   FALSE},
#ifdef FEAT_GUI
    {(int)KE_LEFTMOUSE_NM,      MOUSE_LEFT,     TRUE,   FALSE},
#endif
    {(int)KE_LEFTDRAG,          MOUSE_LEFT,     FALSE,  TRUE},
    {(int)KE_LEFTRELEASE,       MOUSE_LEFT,     FALSE,  FALSE},
#ifdef FEAT_GUI
    {(int)KE_LEFTRELEASE_NM,    MOUSE_LEFT,     FALSE,  FALSE},
#endif
    {(int)KE_MIDDLEMOUSE,       MOUSE_MIDDLE,   TRUE,   FALSE},
    {(int)KE_MIDDLEDRAG,        MOUSE_MIDDLE,   FALSE,  TRUE},
    {(int)KE_MIDDLERELEASE,     MOUSE_MIDDLE,   FALSE,  FALSE},
    {(int)KE_RIGHTMOUSE,        MOUSE_RIGHT,    TRUE,   FALSE},
    {(int)KE_RIGHTDRAG,         MOUSE_RIGHT,    FALSE,  TRUE},
    {(int)KE_RIGHTRELEASE,      MOUSE_RIGHT,    FALSE,  FALSE},
    {(int)KE_X1MOUSE,           MOUSE_X1,       TRUE,   FALSE},
    {(int)KE_X1DRAG,            MOUSE_X1,       FALSE,  TRUE},
    {(int)KE_X1RELEASE,         MOUSE_X1,       FALSE,  FALSE},
    {(int)KE_X2MOUSE,           MOUSE_X2,       TRUE,   FALSE},
    {(int)KE_X2DRAG,            MOUSE_X2,       FALSE,  TRUE},
    {(int)KE_X2RELEASE,         MOUSE_X2,       FALSE,  FALSE},
    /* DRAG without CLICK */
    {(int)KE_IGNORE,            MOUSE_RELEASE,  FALSE,  TRUE},
    /* RELEASE without CLICK */
    {(int)KE_IGNORE,            MOUSE_RELEASE,  FALSE,  FALSE},
    {0,                         0,              0,      0},
};
#endif /* FEAT_MOUSE */

/*
 * Return the modifier mask bit (MOD_MASK_*) which corresponds to the given
 * modifier name ('S' for Shift, 'C' for Ctrl etc).
 */
    int
name_to_mod_mask(c)
    int     c;
{
    int     i;

    c = TOUPPER_ASC(c);
    for (i = 0; mod_mask_table[i].mod_mask != 0; i++)
        if (c == mod_mask_table[i].name)
            return mod_mask_table[i].mod_flag;
    return 0;
}

/*
 * Check if if there is a special key code for "key" that includes the
 * modifiers specified.
 */
    int
simplify_key(key, modifiers)
    int     key;
    int     *modifiers;
{
    int     i;
    int     key0;
    int     key1;

    if (*modifiers & (MOD_MASK_SHIFT | MOD_MASK_CTRL | MOD_MASK_ALT))
    {
        /* TAB is a special case */
        if (key == TAB && (*modifiers & MOD_MASK_SHIFT))
        {
            *modifiers &= ~MOD_MASK_SHIFT;
            return K_S_TAB;
        }
        key0 = KEY2TERMCAP0(key);
        key1 = KEY2TERMCAP1(key);
        for (i = 0; modifier_keys_table[i] != NUL; i += MOD_KEYS_ENTRY_SIZE)
            if (key0 == modifier_keys_table[i + 3]
                    && key1 == modifier_keys_table[i + 4]
                    && (*modifiers & modifier_keys_table[i]))
            {
                *modifiers &= ~modifier_keys_table[i];
                return TERMCAP2KEY(modifier_keys_table[i + 1],
                                                   modifier_keys_table[i + 2]);
            }
    }
    return key;
}

/*
 * Change <xHome> to <Home>, <xUp> to <Up>, etc.
 */
    int
handle_x_keys(key)
    int     key;
{
    switch (key)
    {
        case K_XUP:     return K_UP;
        case K_XDOWN:   return K_DOWN;
        case K_XLEFT:   return K_LEFT;
        case K_XRIGHT:  return K_RIGHT;
        case K_XHOME:   return K_HOME;
        case K_ZHOME:   return K_HOME;
        case K_XEND:    return K_END;
        case K_ZEND:    return K_END;
        case K_XF1:     return K_F1;
        case K_XF2:     return K_F2;
        case K_XF3:     return K_F3;
        case K_XF4:     return K_F4;
        case K_S_XF1:   return K_S_F1;
        case K_S_XF2:   return K_S_F2;
        case K_S_XF3:   return K_S_F3;
        case K_S_XF4:   return K_S_F4;
    }
    return key;
}

/*
 * Return a string which contains the name of the given key when the given
 * modifiers are down.
 */
    char_u *
get_special_key_name(c, modifiers)
    int     c;
    int     modifiers;
{
    static char_u string[MAX_KEY_NAME_LEN + 1];

    int     i, idx;
    int     table_idx;
    char_u  *s;

    string[0] = '<';
    idx = 1;

    /* Key that stands for a normal character. */
    if (IS_SPECIAL(c) && KEY2TERMCAP0(c) == KS_KEY)
        c = KEY2TERMCAP1(c);

    /*
     * Translate shifted special keys into unshifted keys and set modifier.
     * Same for CTRL and ALT modifiers.
     */
    if (IS_SPECIAL(c))
    {
        for (i = 0; modifier_keys_table[i] != 0; i += MOD_KEYS_ENTRY_SIZE)
            if (       KEY2TERMCAP0(c) == (int)modifier_keys_table[i + 1]
                    && (int)KEY2TERMCAP1(c) == (int)modifier_keys_table[i + 2])
            {
                modifiers |= modifier_keys_table[i];
                c = TERMCAP2KEY(modifier_keys_table[i + 3],
                                                   modifier_keys_table[i + 4]);
                break;
            }
    }

    /* try to find the key in the special key table */
    table_idx = find_special_key_in_table(c);

    /*
     * When not a known special key, and not a printable character, try to
     * extract modifiers.
     */
    if (c > 0
#ifdef FEAT_MBYTE
            && (*mb_char2len)(c) == 1
#endif
       )
    {
        if (table_idx < 0
                && (!vim_isprintc(c) || (c & 0x7f) == ' ')
                && (c & 0x80))
        {
            c &= 0x7f;
            modifiers |= MOD_MASK_ALT;
            /* try again, to find the un-alted key in the special key table */
            table_idx = find_special_key_in_table(c);
        }
        if (table_idx < 0 && !vim_isprintc(c) && c < ' ')
        {
#ifdef EBCDIC
            c = CtrlChar(c);
#else
            c += '@';
#endif
            modifiers |= MOD_MASK_CTRL;
        }
    }

    /* translate the modifier into a string */
    for (i = 0; mod_mask_table[i].name != 'A'; i++)
        if ((modifiers & mod_mask_table[i].mod_mask)
                                                == mod_mask_table[i].mod_flag)
        {
            string[idx++] = mod_mask_table[i].name;
            string[idx++] = (char_u)'-';
        }

    if (table_idx < 0)          /* unknown special key, may output t_xx */
    {
        if (IS_SPECIAL(c))
        {
            string[idx++] = 't';
            string[idx++] = '_';
            string[idx++] = KEY2TERMCAP0(c);
            string[idx++] = KEY2TERMCAP1(c);
        }
        /* Not a special key, only modifiers, output directly */
        else
        {
#ifdef FEAT_MBYTE
            if (has_mbyte && (*mb_char2len)(c) > 1)
                idx += (*mb_char2bytes)(c, string + idx);
            else
#endif
            if (vim_isprintc(c))
                string[idx++] = c;
            else
            {
                s = transchar(c);
                while (*s)
                    string[idx++] = *s++;
            }
        }
    }
    else                /* use name of special key */
    {
        STRCPY(string + idx, key_names_table[table_idx].name);
        idx = (int)STRLEN(string);
    }
    string[idx++] = '>';
    string[idx] = NUL;
    return string;
}

/*
 * Try translating a <> name at (*srcp)[] to dst[].
 * Return the number of characters added to dst[], zero for no match.
 * If there is a match, srcp is advanced to after the <> name.
 * dst[] must be big enough to hold the result (up to six characters)!
 */
    int
trans_special(srcp, dst, keycode)
    char_u      **srcp;
    char_u      *dst;
    int         keycode; /* prefer key code, e.g. K_DEL instead of DEL */
{
    int         modifiers = 0;
    int         key;
    int         dlen = 0;

    key = find_special_key(srcp, &modifiers, keycode, FALSE);
    if (key == 0)
        return 0;

    /* Put the appropriate modifier in a string */
    if (modifiers != 0)
    {
        dst[dlen++] = K_SPECIAL;
        dst[dlen++] = KS_MODIFIER;
        dst[dlen++] = modifiers;
    }

    if (IS_SPECIAL(key))
    {
        dst[dlen++] = K_SPECIAL;
        dst[dlen++] = KEY2TERMCAP0(key);
        dst[dlen++] = KEY2TERMCAP1(key);
    }
#ifdef FEAT_MBYTE
    else if (has_mbyte && !keycode)
        dlen += (*mb_char2bytes)(key, dst + dlen);
#endif
    else if (keycode)
        dlen = (int)(add_char2buf(key, dst + dlen) - dst);
    else
        dst[dlen++] = key;

    return dlen;
}

/*
 * Try translating a <> name at (*srcp)[], return the key and modifiers.
 * srcp is advanced to after the <> name.
 * returns 0 if there is no match.
 */
    int
find_special_key(srcp, modp, keycode, keep_x_key)
    char_u      **srcp;
    int         *modp;
    int         keycode;     /* prefer key code, e.g. K_DEL instead of DEL */
    int         keep_x_key;  /* don't translate xHome to Home key */
{
    char_u      *last_dash;
    char_u      *end_of_name;
    char_u      *src;
    char_u      *bp;
    int         modifiers;
    int         bit;
    int         key;
    unsigned long n;

    src = *srcp;
    if (src[0] != '<')
        return 0;

    /* Find end of modifier list */
    last_dash = src;
    for (bp = src + 1; *bp == '-' || vim_isIDc(*bp); bp++)
    {
        if (*bp == '-')
        {
            last_dash = bp;
            if (bp[1] != NUL && bp[2] == '>')
                ++bp;   /* anything accepted, like <C-?> */
        }
        if (bp[0] == 't' && bp[1] == '_' && bp[2] && bp[3])
            bp += 3;    /* skip t_xx, xx may be '-' or '>' */
    }

    if (*bp == '>')     /* found matching '>' */
    {
        end_of_name = bp + 1;

        if (STRNICMP(src + 1, "char-", 5) == 0 && VIM_ISDIGIT(src[6]))
        {
            /* <Char-123> or <Char-033> or <Char-0x33> */
            vim_str2nr(src + 6, NULL, NULL, TRUE, TRUE, NULL, &n);
            *modp = 0;
            *srcp = end_of_name;
            return (int)n;
        }

        /* Which modifiers are given? */
        modifiers = 0x0;
        for (bp = src + 1; bp < last_dash; bp++)
        {
            if (*bp != '-')
            {
                bit = name_to_mod_mask(*bp);
                if (bit == 0x0)
                    break;      /* Illegal modifier name */
                modifiers |= bit;
            }
        }

        /*
         * Legal modifier name.
         */
        if (bp >= last_dash)
        {
            /*
             * Modifier with single letter, or special key name.
             */
            if (modifiers != 0 && last_dash[2] == '>')
                key = last_dash[1];
            else
            {
                key = get_special_key_code(last_dash + 1);
                if (!keep_x_key)
                    key = handle_x_keys(key);
            }

            /*
             * get_special_key_code() may return NUL for invalid
             * special key name.
             */
            if (key != NUL)
            {
                /*
                 * Only use a modifier when there is no special key code that
                 * includes the modifier.
                 */
                key = simplify_key(key, &modifiers);

                if (!keycode)
                {
                    /* don't want keycode, use single byte code */
                    if (key == K_BS)
                        key = BS;
                    else if (key == K_DEL || key == K_KDEL)
                        key = DEL;
                }

                /*
                 * Normal Key with modifier: Try to make a single byte code.
                 */
                if (!IS_SPECIAL(key))
                    key = extract_modifiers(key, &modifiers);

                *modp = modifiers;
                *srcp = end_of_name;
                return key;
            }
        }
    }
    return 0;
}

/*
 * Try to include modifiers in the key.
 * Changes "Shift-a" to 'A', "Alt-A" to 0xc0, etc.
 */
    int
extract_modifiers(key, modp)
    int     key;
    int     *modp;
{
    int modifiers = *modp;

#ifdef MACOS
    /* Command-key really special, No fancynest */
    if (!(modifiers & MOD_MASK_CMD))
#endif
    if ((modifiers & MOD_MASK_SHIFT) && ASCII_ISALPHA(key))
    {
        key = TOUPPER_ASC(key);
        modifiers &= ~MOD_MASK_SHIFT;
    }
    if ((modifiers & MOD_MASK_CTRL)
#ifdef EBCDIC
            /* * TODO: EBCDIC Better use:
             * && (Ctrl_chr(key) || key == '?')
             * ???  */
            && strchr("?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_", key)
                                                       != NULL
#else
            && ((key >= '?' && key <= '_') || ASCII_ISALPHA(key))
#endif
            )
    {
        key = Ctrl_chr(key);
        modifiers &= ~MOD_MASK_CTRL;
        /* <C-@> is <Nul> */
        if (key == 0)
            key = K_ZERO;
    }
#ifdef MACOS
    /* Command-key really special, No fancynest */
    if (!(modifiers & MOD_MASK_CMD))
#endif
    if ((modifiers & MOD_MASK_ALT) && key < 0x80
#ifdef FEAT_MBYTE
            && !enc_dbcs                /* avoid creating a lead byte */
#endif
            )
    {
        key |= 0x80;
        modifiers &= ~MOD_MASK_ALT;     /* remove the META modifier */
    }

    *modp = modifiers;
    return key;
}

/*
 * Try to find key "c" in the special key table.
 * Return the index when found, -1 when not found.
 */
    int
find_special_key_in_table(c)
    int     c;
{
    int     i;

    for (i = 0; key_names_table[i].name != NULL; i++)
        if (c == key_names_table[i].key)
            break;
    if (key_names_table[i].name == NULL)
        i = -1;
    return i;
}

/*
 * Find the special key with the given name (the given string does not have to
 * end with NUL, the name is assumed to end before the first non-idchar).
 * If the name starts with "t_" the next two characters are interpreted as a
 * termcap name.
 * Return the key code, or 0 if not found.
 */
    int
get_special_key_code(name)
    char_u  *name;
{
    char_u  *table_name;
    char_u  string[3];
    int     i, j;

    /*
     * If it's <t_xx> we get the code for xx from the termcap
     */
    if (name[0] == 't' && name[1] == '_' && name[2] != NUL && name[3] != NUL)
    {
        string[0] = name[2];
        string[1] = name[3];
        string[2] = NUL;
        if (add_termcap_entry(string, FALSE) == OK)
            return TERMCAP2KEY(name[2], name[3]);
    }
    else
        for (i = 0; key_names_table[i].name != NULL; i++)
        {
            table_name = key_names_table[i].name;
            for (j = 0; vim_isIDc(name[j]) && table_name[j] != NUL; j++)
                if (TOLOWER_ASC(table_name[j]) != TOLOWER_ASC(name[j]))
                    break;
            if (!vim_isIDc(name[j]) && table_name[j] == NUL)
                return key_names_table[i].key;
        }
    return 0;
}

#if defined(FEAT_CMDL_COMPL) || defined(PROTO)
    char_u *
get_key_name(i)
    int     i;
{
    if (i >= (int)KEY_NAMES_TABLE_LEN)
        return NULL;
    return  key_names_table[i].name;
}
#endif

#if defined(FEAT_MOUSE) || defined(PROTO)
/*
 * Look up the given mouse code to return the relevant information in the other
 * arguments.  Return which button is down or was released.
 */
    int
get_mouse_button(code, is_click, is_drag)
    int     code;
    int     *is_click;
    int     *is_drag;
{
    int     i;

    for (i = 0; mouse_table[i].pseudo_code; i++)
        if (code == mouse_table[i].pseudo_code)
        {
            *is_click = mouse_table[i].is_click;
            *is_drag = mouse_table[i].is_drag;
            return mouse_table[i].button;
        }
    return 0;       /* Shouldn't get here */
}

/*
 * Return the appropriate pseudo mouse event token (KE_LEFTMOUSE etc) based on
 * the given information about which mouse button is down, and whether the
 * mouse was clicked, dragged or released.
 */
    int
get_pseudo_mouse_code(button, is_click, is_drag)
    int     button;     /* eg MOUSE_LEFT */
    int     is_click;
    int     is_drag;
{
    int     i;

    for (i = 0; mouse_table[i].pseudo_code; i++)
        if (button == mouse_table[i].button
            && is_click == mouse_table[i].is_click
            && is_drag == mouse_table[i].is_drag)
        {
#ifdef FEAT_GUI
            /* Trick: a non mappable left click and release has mouse_col -1
             * or added MOUSE_COLOFF.  Used for 'mousefocus' in
             * gui_mouse_moved() */
            if (mouse_col < 0 || mouse_col > MOUSE_COLOFF)
            {
                if (mouse_col < 0)
                    mouse_col = 0;
                else
                    mouse_col -= MOUSE_COLOFF;
                if (mouse_table[i].pseudo_code == (int)KE_LEFTMOUSE)
                    return (int)KE_LEFTMOUSE_NM;
                if (mouse_table[i].pseudo_code == (int)KE_LEFTRELEASE)
                    return (int)KE_LEFTRELEASE_NM;
            }
#endif
            return mouse_table[i].pseudo_code;
        }
    return (int)KE_IGNORE;          /* not recognized, ignore it */
}
#endif /* FEAT_MOUSE */

/*
 * Return the current end-of-line type: EOL_DOS, EOL_UNIX or EOL_MAC.
 */
    int
get_fileformat(buf)
    buf_T       *buf;
{
    int         c = *buf->b_p_ff;

    if (buf->b_p_bin || c == 'u')
        return EOL_UNIX;
    if (c == 'm')
        return EOL_MAC;
    return EOL_DOS;
}

/*
 * Like get_fileformat(), but override 'fileformat' with "p" for "++opt=val"
 * argument.
 */
    int
get_fileformat_force(buf, eap)
    buf_T       *buf;
    exarg_T     *eap;       /* can be NULL! */
{
    int         c;

    if (eap != NULL && eap->force_ff != 0)
        c = eap->cmd[eap->force_ff];
    else
    {
        if ((eap != NULL && eap->force_bin != 0)
                               ? (eap->force_bin == FORCE_BIN) : buf->b_p_bin)
            return EOL_UNIX;
        c = *buf->b_p_ff;
    }
    if (c == 'u')
        return EOL_UNIX;
    if (c == 'm')
        return EOL_MAC;
    return EOL_DOS;
}

/*
 * Set the current end-of-line type to EOL_DOS, EOL_UNIX or EOL_MAC.
 * Sets both 'textmode' and 'fileformat'.
 * Note: Does _not_ set global value of 'textmode'!
 */
    void
set_fileformat(t, opt_flags)
    int         t;
    int         opt_flags;      /* OPT_LOCAL and/or OPT_GLOBAL */
{
    char        *p = NULL;

    switch (t)
    {
    case EOL_DOS:
        p = FF_DOS;
        curbuf->b_p_tx = TRUE;
        break;
    case EOL_UNIX:
        p = FF_UNIX;
        curbuf->b_p_tx = FALSE;
        break;
    case EOL_MAC:
        p = FF_MAC;
        curbuf->b_p_tx = FALSE;
        break;
    }
    if (p != NULL)
        set_string_option_direct((char_u *)"ff", -1, (char_u *)p,
                                                     OPT_FREE | opt_flags, 0);

#ifdef FEAT_WINDOWS
    /* This may cause the buffer to become (un)modified. */
    check_status(curbuf);
    redraw_tabline = TRUE;
#endif
#ifdef FEAT_TITLE
    need_maketitle = TRUE;          /* set window title later */
#endif
}

/*
 * Return the default fileformat from 'fileformats'.
 */
    int
default_fileformat()
{
    switch (*p_ffs)
    {
        case 'm':   return EOL_MAC;
        case 'd':   return EOL_DOS;
    }
    return EOL_UNIX;
}

/*
 * Call shell.  Calls mch_call_shell, with 'shellxquote' added.
 */
    int
call_shell(cmd, opt)
    char_u      *cmd;
    int         opt;
{
    char_u      *ncmd;
    int         retval;
#ifdef FEAT_PROFILE
    proftime_T  wait_time;
#endif

    if (p_verbose > 3)
    {
        verbose_enter();
        smsg((char_u *)_("Calling shell to execute: \"%s\""),
                                                    cmd == NULL ? p_sh : cmd);
        out_char('\n');
        cursor_on();
        verbose_leave();
    }

#ifdef FEAT_PROFILE
    if (do_profiling == PROF_YES)
        prof_child_enter(&wait_time);
#endif

    if (*p_sh == NUL)
    {
        EMSG(_(e_shellempty));
        retval = -1;
    }
    else
    {
#ifdef FEAT_GUI_MSWIN
        /* Don't hide the pointer while executing a shell command. */
        gui_mch_mousehide(FALSE);
#endif
#ifdef FEAT_GUI
        ++hold_gui_events;
#endif
        /* The external command may update a tags file, clear cached tags. */
        tag_freematch();

        if (cmd == NULL || *p_sxq == NUL)
            retval = mch_call_shell(cmd, opt);
        else
        {
            ncmd = alloc((unsigned)(STRLEN(cmd) + STRLEN(p_sxq) * 2 + 1));
            if (ncmd != NULL)
            {
                STRCPY(ncmd, p_sxq);
                STRCAT(ncmd, cmd);
                STRCAT(ncmd, p_sxq);
                retval = mch_call_shell(ncmd, opt);
                vim_free(ncmd);
            }
            else
                retval = -1;
        }
#ifdef FEAT_GUI
        --hold_gui_events;
#endif
        /*
         * Check the window size, in case it changed while executing the
         * external command.
         */
        shell_resized_check();
    }

#ifdef FEAT_EVAL
    set_vim_var_nr(VV_SHELL_ERROR, (long)retval);
# ifdef FEAT_PROFILE
    if (do_profiling == PROF_YES)
        prof_child_exit(&wait_time);
# endif
#endif

    return retval;
}

/*
 * VISUAL, SELECTMODE and OP_PENDING State are never set, they are equal to
 * NORMAL State with a condition.  This function returns the real State.
 */
    int
get_real_state()
{
    if (State & NORMAL)
    {
#ifdef FEAT_VISUAL
        if (VIsual_active)
        {
            if (VIsual_select)
                return SELECTMODE;
            return VISUAL;
        }
        else
#endif
            if (finish_op)
                return OP_PENDING;
    }
    return State;
}

#if defined(FEAT_MBYTE) || defined(PROTO)
/*
 * Return TRUE if "p" points to just after a path separator.
 * Take care of multi-byte characters.
 * "b" must point to the start of the file name
 */
    int
after_pathsep(b, p)
    char_u      *b;
    char_u      *p;
{
    return vim_ispathsep(p[-1])
                             && (!has_mbyte || (*mb_head_off)(b, p - 1) == 0);
}
#endif

/*
 * Return TRUE if file names "f1" and "f2" are in the same directory.
 * "f1" may be a short name, "f2" must be a full path.
 */
    int
same_directory(f1, f2)
    char_u      *f1;
    char_u      *f2;
{
    char_u      ffname[MAXPATHL];
    char_u      *t1;
    char_u      *t2;

    /* safety check */
    if (f1 == NULL || f2 == NULL)
        return FALSE;

    (void)vim_FullName(f1, ffname, MAXPATHL, FALSE);
    t1 = gettail_sep(ffname);
    t2 = gettail_sep(f2);
    return (t1 - ffname == t2 - f2
             && pathcmp((char *)ffname, (char *)f2, (int)(t1 - ffname)) == 0);
}

#if defined(FEAT_SESSION) || defined(MSWIN) || defined(FEAT_GUI_MAC) \
        || ((defined(FEAT_GUI_GTK)) \
                        && ( defined(FEAT_WINDOWS) || defined(FEAT_DND)) ) \
        || defined(FEAT_SUN_WORKSHOP) || defined(FEAT_NETBEANS_INTG) \
        || defined(PROTO)
/*
 * Change to a file's directory.
 * Caller must call shorten_fnames()!
 * Return OK or FAIL.
 */
    int
vim_chdirfile(fname)
    char_u      *fname;
{
    char_u      dir[MAXPATHL];

    vim_strncpy(dir, fname, MAXPATHL - 1);
    *gettail_sep(dir) = NUL;
    return mch_chdir((char *)dir) == 0 ? OK : FAIL;
}
#endif

#if defined(STAT_IGNORES_SLASH) || defined(PROTO)
/*
 * Check if "name" ends in a slash and is not a directory.
 * Used for systems where stat() ignores a trailing slash on a file name.
 * The Vim code assumes a trailing slash is only ignored for a directory.
 */
    int
illegal_slash(name)
    char *name;
{
    if (name[0] == NUL)
        return FALSE;       /* no file name is not illegal */
    if (name[strlen(name) - 1] != '/')
        return FALSE;       /* no trailing slash */
    if (mch_isdir((char_u *)name))
        return FALSE;       /* trailing slash for a directory */
    return TRUE;
}
#endif

#if defined(CURSOR_SHAPE) || defined(PROTO)

/*
 * Handling of cursor and mouse pointer shapes in various modes.
 */

cursorentry_T shape_table[SHAPE_IDX_COUNT] =
{
    /* The values will be filled in from the 'guicursor' and 'mouseshape'
     * defaults when Vim starts.
     * Adjust the SHAPE_IDX_ defines when making changes! */
    {0, 0, 0, 700L, 400L, 250L, 0, 0, "n", SHAPE_CURSOR+SHAPE_MOUSE},
    {0, 0, 0, 700L, 400L, 250L, 0, 0, "v", SHAPE_CURSOR+SHAPE_MOUSE},
    {0, 0, 0, 700L, 400L, 250L, 0, 0, "i", SHAPE_CURSOR+SHAPE_MOUSE},
    {0, 0, 0, 700L, 400L, 250L, 0, 0, "r", SHAPE_CURSOR+SHAPE_MOUSE},
    {0, 0, 0, 700L, 400L, 250L, 0, 0, "c", SHAPE_CURSOR+SHAPE_MOUSE},
    {0, 0, 0, 700L, 400L, 250L, 0, 0, "ci", SHAPE_CURSOR+SHAPE_MOUSE},
    {0, 0, 0, 700L, 400L, 250L, 0, 0, "cr", SHAPE_CURSOR+SHAPE_MOUSE},
    {0, 0, 0, 700L, 400L, 250L, 0, 0, "o", SHAPE_CURSOR+SHAPE_MOUSE},
    {0, 0, 0, 700L, 400L, 250L, 0, 0, "ve", SHAPE_CURSOR+SHAPE_MOUSE},
    {0, 0, 0,   0L,   0L,   0L, 0, 0, "e", SHAPE_MOUSE},
    {0, 0, 0,   0L,   0L,   0L, 0, 0, "s", SHAPE_MOUSE},
    {0, 0, 0,   0L,   0L,   0L, 0, 0, "sd", SHAPE_MOUSE},
    {0, 0, 0,   0L,   0L,   0L, 0, 0, "vs", SHAPE_MOUSE},
    {0, 0, 0,   0L,   0L,   0L, 0, 0, "vd", SHAPE_MOUSE},
    {0, 0, 0,   0L,   0L,   0L, 0, 0, "m", SHAPE_MOUSE},
    {0, 0, 0,   0L,   0L,   0L, 0, 0, "ml", SHAPE_MOUSE},
    {0, 0, 0, 100L, 100L, 100L, 0, 0, "sm", SHAPE_CURSOR},
};

#ifdef FEAT_MOUSESHAPE
/*
 * Table with names for mouse shapes.  Keep in sync with all the tables for
 * mch_set_mouse_shape()!.
 */
static char * mshape_names[] =
{
    "arrow",    /* default, must be the first one */
    "blank",    /* hidden */
    "beam",
    "updown",
    "udsizing",
    "leftright",
    "lrsizing",
    "busy",
    "no",
    "crosshair",
    "hand1",
    "hand2",
    "pencil",
    "question",
    "rightup-arrow",
    "up-arrow",
    NULL
};
#endif

/*
 * Parse the 'guicursor' option ("what" is SHAPE_CURSOR) or 'mouseshape'
 * ("what" is SHAPE_MOUSE).
 * Returns error message for an illegal option, NULL otherwise.
 */
    char_u *
parse_shape_opt(what)
    int         what;
{
    char_u      *modep;
    char_u      *colonp;
    char_u      *commap;
    char_u      *slashp;
    char_u      *p, *endp;
    int         idx = 0;                /* init for GCC */
    int         all_idx;
    int         len;
    int         i;
    long        n;
    int         found_ve = FALSE;       /* found "ve" flag */
    int         round;

    /*
     * First round: check for errors; second round: do it for real.
     */
    for (round = 1; round <= 2; ++round)
    {
        /*
         * Repeat for all comma separated parts.
         */
#ifdef FEAT_MOUSESHAPE
        if (what == SHAPE_MOUSE)
            modep = p_mouseshape;
        else
#endif
            modep = p_guicursor;
        while (*modep != NUL)
        {
            colonp = vim_strchr(modep, ':');
            if (colonp == NULL)
                return (char_u *)N_("E545: Missing colon");
            if (colonp == modep)
                return (char_u *)N_("E546: Illegal mode");
            commap = vim_strchr(modep, ',');

            /*
             * Repeat for all mode's before the colon.
             * For the 'a' mode, we loop to handle all the modes.
             */
            all_idx = -1;
            while (modep < colonp || all_idx >= 0)
            {
                if (all_idx < 0)
                {
                    /* Find the mode. */
                    if (modep[1] == '-' || modep[1] == ':')
                        len = 1;
                    else
                        len = 2;
                    if (len == 1 && TOLOWER_ASC(modep[0]) == 'a')
                        all_idx = SHAPE_IDX_COUNT - 1;
                    else
                    {
                        for (idx = 0; idx < SHAPE_IDX_COUNT; ++idx)
                            if (STRNICMP(modep, shape_table[idx].name, len)
                                                                         == 0)
                                break;
                        if (idx == SHAPE_IDX_COUNT
                                   || (shape_table[idx].used_for & what) == 0)
                            return (char_u *)N_("E546: Illegal mode");
                        if (len == 2 && modep[0] == 'v' && modep[1] == 'e')
                            found_ve = TRUE;
                    }
                    modep += len + 1;
                }

                if (all_idx >= 0)
                    idx = all_idx--;
                else if (round == 2)
                {
#ifdef FEAT_MOUSESHAPE
                    if (what == SHAPE_MOUSE)
                    {
                        /* Set the default, for the missing parts */
                        shape_table[idx].mshape = 0;
                    }
                    else
#endif
                    {
                        /* Set the defaults, for the missing parts */
                        shape_table[idx].shape = SHAPE_BLOCK;
                        shape_table[idx].blinkwait = 700L;
                        shape_table[idx].blinkon = 400L;
                        shape_table[idx].blinkoff = 250L;
                    }
                }

                /* Parse the part after the colon */
                for (p = colonp + 1; *p && *p != ','; )
                {
#ifdef FEAT_MOUSESHAPE
                    if (what == SHAPE_MOUSE)
                    {
                        for (i = 0; ; ++i)
                        {
                            if (mshape_names[i] == NULL)
                            {
                                if (!VIM_ISDIGIT(*p))
                                    return (char_u *)N_("E547: Illegal mouseshape");
                                if (round == 2)
                                    shape_table[idx].mshape =
                                              getdigits(&p) + MSHAPE_NUMBERED;
                                else
                                    (void)getdigits(&p);
                                break;
                            }
                            len = (int)STRLEN(mshape_names[i]);
                            if (STRNICMP(p, mshape_names[i], len) == 0)
                            {
                                if (round == 2)
                                    shape_table[idx].mshape = i;
                                p += len;
                                break;
                            }
                        }
                    }
                    else /* if (what == SHAPE_MOUSE) */
#endif
                    {
                        /*
                         * First handle the ones with a number argument.
                         */
                        i = *p;
                        len = 0;
                        if (STRNICMP(p, "ver", 3) == 0)
                            len = 3;
                        else if (STRNICMP(p, "hor", 3) == 0)
                            len = 3;
                        else if (STRNICMP(p, "blinkwait", 9) == 0)
                            len = 9;
                        else if (STRNICMP(p, "blinkon", 7) == 0)
                            len = 7;
                        else if (STRNICMP(p, "blinkoff", 8) == 0)
                            len = 8;
                        if (len != 0)
                        {
                            p += len;
                            if (!VIM_ISDIGIT(*p))
                                return (char_u *)N_("E548: digit expected");
                            n = getdigits(&p);
                            if (len == 3)   /* "ver" or "hor" */
                            {
                                if (n == 0)
                                    return (char_u *)N_("E549: Illegal percentage");
                                if (round == 2)
                                {
                                    if (TOLOWER_ASC(i) == 'v')
                                        shape_table[idx].shape = SHAPE_VER;
                                    else
                                        shape_table[idx].shape = SHAPE_HOR;
                                    shape_table[idx].percentage = n;
                                }
                            }
                            else if (round == 2)
                            {
                                if (len == 9)
                                    shape_table[idx].blinkwait = n;
                                else if (len == 7)
                                    shape_table[idx].blinkon = n;
                                else
                                    shape_table[idx].blinkoff = n;
                            }
                        }
                        else if (STRNICMP(p, "block", 5) == 0)
                        {
                            if (round == 2)
                                shape_table[idx].shape = SHAPE_BLOCK;
                            p += 5;
                        }
                        else    /* must be a highlight group name then */
                        {
                            endp = vim_strchr(p, '-');
                            if (commap == NULL)             /* last part */
                            {
                                if (endp == NULL)
                                    endp = p + STRLEN(p);   /* find end of part */
                            }
                            else if (endp > commap || endp == NULL)
                                endp = commap;
                            slashp = vim_strchr(p, '/');
                            if (slashp != NULL && slashp < endp)
                            {
                                /* "group/langmap_group" */
                                i = syn_check_group(p, (int)(slashp - p));
                                p = slashp + 1;
                            }
                            if (round == 2)
                            {
                                shape_table[idx].id = syn_check_group(p,
                                                             (int)(endp - p));
                                shape_table[idx].id_lm = shape_table[idx].id;
                                if (slashp != NULL && slashp < endp)
                                    shape_table[idx].id = i;
                            }
                            p = endp;
                        }
                    } /* if (what != SHAPE_MOUSE) */

                    if (*p == '-')
                        ++p;
                }
            }
            modep = p;
            if (*modep == ',')
                ++modep;
        }
    }

    /* If the 's' flag is not given, use the 'v' cursor for 's' */
    if (!found_ve)
    {
#ifdef FEAT_MOUSESHAPE
        if (what == SHAPE_MOUSE)
        {
            shape_table[SHAPE_IDX_VE].mshape = shape_table[SHAPE_IDX_V].mshape;
        }
        else
#endif
        {
            shape_table[SHAPE_IDX_VE].shape = shape_table[SHAPE_IDX_V].shape;
            shape_table[SHAPE_IDX_VE].percentage =
                                         shape_table[SHAPE_IDX_V].percentage;
            shape_table[SHAPE_IDX_VE].blinkwait =
                                          shape_table[SHAPE_IDX_V].blinkwait;
            shape_table[SHAPE_IDX_VE].blinkon =
                                            shape_table[SHAPE_IDX_V].blinkon;
            shape_table[SHAPE_IDX_VE].blinkoff =
                                           shape_table[SHAPE_IDX_V].blinkoff;
            shape_table[SHAPE_IDX_VE].id = shape_table[SHAPE_IDX_V].id;
            shape_table[SHAPE_IDX_VE].id_lm = shape_table[SHAPE_IDX_V].id_lm;
        }
    }

    return NULL;
}

# if defined(MCH_CURSOR_SHAPE) || defined(FEAT_GUI) \
        || defined(FEAT_MOUSESHAPE) || defined(PROTO)
/*
 * Return the index into shape_table[] for the current mode.
 * When "mouse" is TRUE, consider indexes valid for the mouse pointer.
 */
    int
get_shape_idx(mouse)
    int mouse;
{
#ifdef FEAT_MOUSESHAPE
    if (mouse && (State == HITRETURN || State == ASKMORE))
    {
# ifdef FEAT_GUI
        int x, y;
        gui_mch_getmouse(&x, &y);
        if (Y_2_ROW(y) == Rows - 1)
            return SHAPE_IDX_MOREL;
# endif
        return SHAPE_IDX_MORE;
    }
    if (mouse && drag_status_line)
        return SHAPE_IDX_SDRAG;
# ifdef FEAT_VERTSPLIT
    if (mouse && drag_sep_line)
        return SHAPE_IDX_VDRAG;
# endif
#endif
    if (!mouse && State == SHOWMATCH)
        return SHAPE_IDX_SM;
#ifdef FEAT_VREPLACE
    if (State & VREPLACE_FLAG)
        return SHAPE_IDX_R;
#endif
    if (State & REPLACE_FLAG)
        return SHAPE_IDX_R;
    if (State & INSERT)
        return SHAPE_IDX_I;
    if (State & CMDLINE)
    {
        if (cmdline_at_end())
            return SHAPE_IDX_C;
        if (cmdline_overstrike())
            return SHAPE_IDX_CR;
        return SHAPE_IDX_CI;
    }
    if (finish_op)
        return SHAPE_IDX_O;
#ifdef FEAT_VISUAL
    if (VIsual_active)
    {
        if (*p_sel == 'e')
            return SHAPE_IDX_VE;
        else
            return SHAPE_IDX_V;
    }
#endif
    return SHAPE_IDX_N;
}
#endif

# if defined(FEAT_MOUSESHAPE) || defined(PROTO)
static int old_mouse_shape = 0;

/*
 * Set the mouse shape:
 * If "shape" is -1, use shape depending on the current mode,
 * depending on the current state.
 * If "shape" is -2, only update the shape when it's CLINE or STATUS (used
 * when the mouse moves off the status or command line).
 */
    void
update_mouseshape(shape_idx)
    int shape_idx;
{
    int new_mouse_shape;

    /* Only works in GUI mode. */
    if (!gui.in_use || gui.starting)
        return;

    /* Postpone the updating when more is to come.  Speeds up executing of
     * mappings. */
    if (shape_idx == -1 && char_avail())
    {
        postponed_mouseshape = TRUE;
        return;
    }

    /* When ignoring the mouse don't change shape on the statusline. */
    if (*p_mouse == NUL
            && (shape_idx == SHAPE_IDX_CLINE
                || shape_idx == SHAPE_IDX_STATUS
                || shape_idx == SHAPE_IDX_VSEP))
        shape_idx = -2;

    if (shape_idx == -2
            && old_mouse_shape != shape_table[SHAPE_IDX_CLINE].mshape
            && old_mouse_shape != shape_table[SHAPE_IDX_STATUS].mshape
            && old_mouse_shape != shape_table[SHAPE_IDX_VSEP].mshape)
        return;
    if (shape_idx < 0)
        new_mouse_shape = shape_table[get_shape_idx(TRUE)].mshape;
    else
        new_mouse_shape = shape_table[shape_idx].mshape;
    if (new_mouse_shape != old_mouse_shape)
    {
        mch_set_mouse_shape(new_mouse_shape);
        old_mouse_shape = new_mouse_shape;
    }
    postponed_mouseshape = FALSE;
}
# endif

#endif /* CURSOR_SHAPE */


#ifdef FEAT_CRYPT
/*
 * Optional encryption support.
 * Mohsin Ahmed, mosh@sasi.com, 98-09-24
 * Based on zip/crypt sources.
 *
 * NOTE FOR USA: Since 2000 exporting this code from the USA is allowed to
 * most countries.  There are a few exceptions, but that still should not be a
 * problem since this code was originally created in Europe and India.
 */

/* from zip.h */

typedef unsigned short ush;     /* unsigned 16-bit value */
typedef unsigned long  ulg;     /* unsigned 32-bit value */

static void make_crc_tab __ARGS((void));

static ulg crc_32_tab[256];

/*
 * Fill the CRC table.
 */
    static void
make_crc_tab()
{
    ulg         s,t,v;
    static int  done = FALSE;

    if (done)
        return;
    for (t = 0; t < 256; t++)
    {
        v = t;
        for (s = 0; s < 8; s++)
            v = (v >> 1) ^ ((v & 1) * (ulg)0xedb88320L);
        crc_32_tab[t] = v;
    }
    done = TRUE;
}

#define CRC32(c, b) (crc_32_tab[((int)(c) ^ (b)) & 0xff] ^ ((c) >> 8))


static ulg keys[3]; /* keys defining the pseudo-random sequence */

/*
 * Return the next byte in the pseudo-random sequence
 */
    int
decrypt_byte()
{
    ush temp;

    temp = (ush)keys[2] | 2;
    return (int)(((unsigned)(temp * (temp ^ 1)) >> 8) & 0xff);
}

/*
 * Update the encryption keys with the next byte of plain text
 */
    int
update_keys(c)
    int c;                      /* byte of plain text */
{
    keys[0] = CRC32(keys[0], c);
    keys[1] += keys[0] & 0xff;
    keys[1] = keys[1] * 134775813L + 1;
    keys[2] = CRC32(keys[2], (int)(keys[1] >> 24));
    return c;
}

/*
 * Initialize the encryption keys and the random header according to
 * the given password.
 * If "passwd" is NULL or empty, don't do anything.
 */
    void
crypt_init_keys(passwd)
    char_u *passwd;             /* password string with which to modify keys */
{
    if (passwd != NULL && *passwd != NUL)
    {
        make_crc_tab();
        keys[0] = 305419896L;
        keys[1] = 591751049L;
        keys[2] = 878082192L;
        while (*passwd != '\0')
            update_keys((int)*passwd++);
    }
}

/*
 * Ask the user for a crypt key.
 * When "store" is TRUE, the new key in stored in the 'key' option, and the
 * 'key' option value is returned: Don't free it.
 * When "store" is FALSE, the typed key is returned in allocated memory.
 * Returns NULL on failure.
 */
    char_u *
get_crypt_key(store, twice)
    int         store;
    int         twice;      /* Ask for the key twice. */
{
    char_u      *p1, *p2 = NULL;
    int         round;

    for (round = 0; ; ++round)
    {
        cmdline_star = TRUE;
        cmdline_row = msg_row;
        p1 = getcmdline_prompt(NUL, round == 0
                ? (char_u *)_("Enter encryption key: ")
                : (char_u *)_("Enter same key again: "), 0, EXPAND_NOTHING,
                NULL);
        cmdline_star = FALSE;

        if (p1 == NULL)
            break;

        if (round == twice)
        {
            if (p2 != NULL && STRCMP(p1, p2) != 0)
            {
                MSG(_("Keys don't match!"));
                vim_free(p1);
                vim_free(p2);
                p2 = NULL;
                round = -1;             /* do it again */
                continue;
            }
            if (store)
            {
                set_option_value((char_u *)"key", 0L, p1, OPT_LOCAL);
                vim_free(p1);
                p1 = curbuf->b_p_key;
            }
            break;
        }
        p2 = p1;
    }

    /* since the user typed this, no need to wait for return */
    need_wait_return = FALSE;
    msg_didout = FALSE;

    vim_free(p2);
    return p1;
}

#endif /* FEAT_CRYPT */

/* TODO: make some #ifdef for this */
/*--------[ file searching ]-------------------------------------------------*/
/*
 * File searching functions for 'path', 'tags' and 'cdpath' options.
 * External visible functions:
 * vim_findfile_init()          creates/initialises the search context
 * vim_findfile_free_visited()  free list of visited files/dirs of search
 *                              context
 * vim_findfile()               find a file in the search context
 * vim_findfile_cleanup()       cleanup/free search context created by
 *                              vim_findfile_init()
 *
 * All static functions and variables start with 'ff_'
 *
 * In general it works like this:
 * First you create yourself a search context by calling vim_findfile_init().
 * It is possible to give a search context from a previous call to
 * vim_findfile_init(), so it can be reused. After this you call vim_findfile()
 * until you are satisfied with the result or it returns NULL. On every call it
 * returns the next file which matches the conditions given to
 * vim_findfile_init(). If it doesn't find a next file it returns NULL.
 *
 * It is possible to call vim_findfile_init() again to reinitialise your search
 * with some new parameters. Don't forget to pass your old search context to
 * it, so it can reuse it and especially reuse the list of already visited
 * directories. If you want to delete the list of already visited directories
 * simply call vim_findfile_free_visited().
 *
 * When you are done call vim_findfile_cleanup() to free the search context.
 *
 * The function vim_findfile_init() has a long comment, which describes the
 * needed parameters.
 *
 *
 *
 * ATTENTION:
 * ==========
 *      Also we use an allocated search context here, this functions are NOT
 *      thread-safe!!!!!
 *
 *      To minimize parameter passing (or because I'm to lazy), only the
 *      external visible functions get a search context as a parameter. This is
 *      then assigned to a static global, which is used throughout the local
 *      functions.
 */

/*
 * type for the directory search stack
 */
typedef struct ff_stack
{
    struct ff_stack     *ffs_prev;

    /* the fix part (no wildcards) and the part containing the wildcards
     * of the search path
     */
    char_u              *ffs_fix_path;
#ifdef FEAT_PATH_EXTRA
    char_u              *ffs_wc_path;
#endif

    /* files/dirs found in the above directory, matched by the first wildcard
     * of wc_part
     */
    char_u              **ffs_filearray;
    int                 ffs_filearray_size;
    char_u              ffs_filearray_cur;   /* needed for partly handled dirs */

    /* to store status of partly handled directories
     * 0: we work on this directory for the first time
     * 1: this directory was partly searched in an earlier step
     */
    int                 ffs_stage;

    /* How deep are we in the directory tree?
     * Counts backward from value of level parameter to vim_findfile_init
     */
    int                 ffs_level;

    /* Did we already expand '**' to an empty string? */
    int                 ffs_star_star_empty;
} ff_stack_T;

/*
 * type for already visited directories or files.
 */
typedef struct ff_visited
{
    struct ff_visited   *ffv_next;

#ifdef FEAT_PATH_EXTRA
    /* Visited directories are different if the wildcard string are
     * different. So we have to save it.
     */
    char_u              *ffv_wc_path;
#endif
    /* for unix use inode etc for comparison (needed because of links), else
     * use filename.
     */
#ifdef UNIX
    int                 ffv_dev_valid;  /* ffv_dev and ffv_ino were set */
    dev_t               ffv_dev;        /* device number */
    ino_t               ffv_ino;        /* inode number */
#endif
    /* The memory for this struct is allocated according to the length of
     * ffv_fname.
     */
    char_u              ffv_fname[1];   /* actually longer */
} ff_visited_T;

/*
 * We might have to manage several visited lists during a search.
 * This is especially needed for the tags option. If tags is set to:
 *      "./++/tags,./++/TAGS,++/tags"  (replace + with *)
 * So we have to do 3 searches:
 *   1) search from the current files directory downward for the file "tags"
 *   2) search from the current files directory downward for the file "TAGS"
 *   3) search from Vims current directory downwards for the file "tags"
 * As you can see, the first and the third search are for the same file, so for
 * the third search we can use the visited list of the first search. For the
 * second search we must start from a empty visited list.
 * The struct ff_visited_list_hdr is used to manage a linked list of already
 * visited lists.
 */
typedef struct ff_visited_list_hdr
{
    struct ff_visited_list_hdr  *ffvl_next;

    /* the filename the attached visited list is for */
    char_u                      *ffvl_filename;

    ff_visited_T                *ffvl_visited_list;

} ff_visited_list_hdr_T;


/*
 * '**' can be expanded to several directory levels.
 * Set the default maximum depth.
 */
#define FF_MAX_STAR_STAR_EXPAND ((char_u)30)

/*
 * The search context:
 *   ffsc_stack_ptr:    the stack for the dirs to search
 *   ffsc_visited_list: the currently active visited list
 *   ffsc_dir_visited_list: the currently active visited list for search dirs
 *   ffsc_visited_lists_list: the list of all visited lists
 *   ffsc_dir_visited_lists_list: the list of all visited lists for search dirs
 *   ffsc_file_to_search:     the file to search for
 *   ffsc_start_dir:    the starting directory, if search path was relative
 *   ffsc_fix_path:     the fix part of the given path (without wildcards)
 *                      Needed for upward search.
 *   ffsc_wc_path:      the part of the given path containing wildcards
 *   ffsc_level:        how many levels of dirs to search downwards
 *   ffsc_stopdirs_v:   array of stop directories for upward search
 *   ffsc_find_what:    FINDFILE_BOTH, FINDFILE_DIR or FINDFILE_FILE
 */
typedef struct ff_search_ctx_T
{
     ff_stack_T                 *ffsc_stack_ptr;
     ff_visited_list_hdr_T      *ffsc_visited_list;
     ff_visited_list_hdr_T      *ffsc_dir_visited_list;
     ff_visited_list_hdr_T      *ffsc_visited_lists_list;
     ff_visited_list_hdr_T      *ffsc_dir_visited_lists_list;
     char_u                     *ffsc_file_to_search;
     char_u                     *ffsc_start_dir;
     char_u                     *ffsc_fix_path;
#ifdef FEAT_PATH_EXTRA
     char_u                     *ffsc_wc_path;
     int                        ffsc_level;
     char_u                     **ffsc_stopdirs_v;
#endif
     int                        ffsc_find_what;
} ff_search_ctx_T;

/* locally needed functions */
#ifdef FEAT_PATH_EXTRA
static int ff_check_visited __ARGS((ff_visited_T **, char_u *, char_u *));
#else
static int ff_check_visited __ARGS((ff_visited_T **, char_u *));
#endif
static void vim_findfile_free_visited_list __ARGS((ff_visited_list_hdr_T **list_headp));
static void ff_free_visited_list __ARGS((ff_visited_T *vl));
static ff_visited_list_hdr_T* ff_get_visited_list __ARGS((char_u *, ff_visited_list_hdr_T **list_headp));
#ifdef FEAT_PATH_EXTRA
static int ff_wc_equal __ARGS((char_u *s1, char_u *s2));
#endif

static void ff_push __ARGS((ff_search_ctx_T *search_ctx, ff_stack_T *stack_ptr));
static ff_stack_T *ff_pop __ARGS((ff_search_ctx_T *search_ctx));
static void ff_clear __ARGS((ff_search_ctx_T *search_ctx));
static void ff_free_stack_element __ARGS((ff_stack_T *stack_ptr));
#ifdef FEAT_PATH_EXTRA
static ff_stack_T *ff_create_stack_element __ARGS((char_u *, char_u *, int, int));
#else
static ff_stack_T *ff_create_stack_element __ARGS((char_u *, int, int));
#endif
#ifdef FEAT_PATH_EXTRA
static int ff_path_in_stoplist __ARGS((char_u *, int, char_u **));
#endif

#if 0
/*
 * if someone likes findfirst/findnext, here are the functions
 * NOT TESTED!!
 */

static void *ff_fn_search_context = NULL;

    char_u *
vim_findfirst(path, filename, level)
    char_u      *path;
    char_u      *filename;
    int         level;
{
    ff_fn_search_context =
        vim_findfile_init(path, filename, NULL, level, TRUE, FALSE,
                ff_fn_search_context, rel_fname);
    if (NULL == ff_fn_search_context)
        return NULL;
    else
        return vim_findnext()
}

    char_u *
vim_findnext()
{
    char_u *ret = vim_findfile(ff_fn_search_context);

    if (NULL == ret)
    {
        vim_findfile_cleanup(ff_fn_search_context);
        ff_fn_search_context = NULL;
    }
    return ret;
}
#endif

/*
 * Initialization routine for vim_findfile.
 *
 * Returns the newly allocated search context or NULL if an error occured.
 *
 * Don't forget to clean up by calling vim_findfile_cleanup() if you are done
 * with the search context.
 *
 * Find the file 'filename' in the directory 'path'.
 * The parameter 'path' may contain wildcards. If so only search 'level'
 * directories deep. The parameter 'level' is the absolute maximum and is
 * not related to restricts given to the '**' wildcard. If 'level' is 100
 * and you use '**200' vim_findfile() will stop after 100 levels.
 *
 * 'filename' cannot contain wildcards!  It is used as-is, no backslashes to
 * escape special characters.
 *
 * If 'stopdirs' is not NULL and nothing is found downward, the search is
 * restarted on the next higher directory level. This is repeated until the
 * start-directory of a search is contained in 'stopdirs'. 'stopdirs' has the
 * format ";*<dirname>*\(;<dirname>\)*;\=$".
 *
 * If the 'path' is relative, the starting dir for the search is either VIM's
 * current dir or if the path starts with "./" the current files dir.
 * If the 'path' is absolut, the starting dir is that part of the path before
 * the first wildcard.
 *
 * Upward search is only done on the starting dir.
 *
 * If 'free_visited' is TRUE the list of already visited files/directories is
 * cleared. Set this to FALSE if you just want to search from another
 * directory, but want to be sure that no directory from a previous search is
 * searched again. This is useful if you search for a file at different places.
 * The list of visited files/dirs can also be cleared with the function
 * vim_findfile_free_visited().
 *
 * Set the parameter 'find_what' to FINDFILE_DIR if you want to search for
 * directories only, FINDFILE_FILE for files only, FINDFILE_BOTH for both.
 *
 * A search context returned by a previous call to vim_findfile_init() can be
 * passed in the parameter "search_ctx_arg".  This context is reused and
 * reinitialized with the new parameters.  The list of already visited
 * directories from this context is only deleted if the parameter
 * "free_visited" is true.  Be aware that the passed "search_ctx_arg" is freed
 * if the reinitialization fails.
 *
 * If you don't have a search context from a previous call "search_ctx_arg"
 * must be NULL.
 *
 * This function silently ignores a few errors, vim_findfile() will have
 * limited functionality then.
 */
    void *
vim_findfile_init(path, filename, stopdirs, level, free_visited, find_what,
                                           search_ctx_arg, tagfile, rel_fname)
    char_u      *path;
    char_u      *filename;
    char_u      *stopdirs UNUSED;
    int         level;
    int         free_visited;
    int         find_what;
    void        *search_ctx_arg;
    int         tagfile;
    char_u      *rel_fname;     /* file name to use for "." */
{
#ifdef FEAT_PATH_EXTRA
    char_u              *wc_part;
#endif
    ff_stack_T          *sptr;
    ff_search_ctx_T     *search_ctx;

    /* If a search context is given by the caller, reuse it, else allocate a
     * new one.
     */
    if (search_ctx_arg != NULL)
        search_ctx = search_ctx_arg;
    else
    {
        search_ctx = (ff_search_ctx_T*)alloc((unsigned)sizeof(ff_search_ctx_T));
        if (search_ctx == NULL)
            goto error_return;
        memset(search_ctx, 0, sizeof(ff_search_ctx_T));
    }
    search_ctx->ffsc_find_what = find_what;

    /* clear the search context, but NOT the visited lists */
    ff_clear(search_ctx);

    /* clear visited list if wanted */
    if (free_visited == TRUE)
        vim_findfile_free_visited(search_ctx);
    else
    {
        /* Reuse old visited lists. Get the visited list for the given
         * filename. If no list for the current filename exists, creates a new
         * one. */
        search_ctx->ffsc_visited_list = ff_get_visited_list(filename,
                                        &search_ctx->ffsc_visited_lists_list);
        if (search_ctx->ffsc_visited_list == NULL)
            goto error_return;
        search_ctx->ffsc_dir_visited_list = ff_get_visited_list(filename,
                                    &search_ctx->ffsc_dir_visited_lists_list);
        if (search_ctx->ffsc_dir_visited_list == NULL)
            goto error_return;
    }

    if (ff_expand_buffer == NULL)
    {
        ff_expand_buffer = (char_u*)alloc(MAXPATHL);
        if (ff_expand_buffer == NULL)
            goto error_return;
    }

    /* Store information on starting dir now if path is relative.
     * If path is absolute, we do that later.  */
    if (path[0] == '.'
            && (vim_ispathsep(path[1]) || path[1] == NUL)
            && (!tagfile || vim_strchr(p_cpo, CPO_DOTTAG) == NULL)
            && rel_fname != NULL)
    {
        int     len = (int)(gettail(rel_fname) - rel_fname);

        if (!vim_isAbsName(rel_fname) && len + 1 < MAXPATHL)
        {
            /* Make the start dir an absolute path name. */
            vim_strncpy(ff_expand_buffer, rel_fname, len);
            search_ctx->ffsc_start_dir = FullName_save(ff_expand_buffer, FALSE);
        }
        else
            search_ctx->ffsc_start_dir = vim_strnsave(rel_fname, len);
        if (search_ctx->ffsc_start_dir == NULL)
            goto error_return;
        if (*++path != NUL)
            ++path;
    }
    else if (*path == NUL || !vim_isAbsName(path))
    {
#ifdef BACKSLASH_IN_FILENAME
        /* "c:dir" needs "c:" to be expanded, otherwise use current dir */
        if (*path != NUL && path[1] == ':')
        {
            char_u  drive[3];

            drive[0] = path[0];
            drive[1] = ':';
            drive[2] = NUL;
            if (vim_FullName(drive, ff_expand_buffer, MAXPATHL, TRUE) == FAIL)
                goto error_return;
            path += 2;
        }
        else
#endif
        if (mch_dirname(ff_expand_buffer, MAXPATHL) == FAIL)
            goto error_return;

        search_ctx->ffsc_start_dir = vim_strsave(ff_expand_buffer);
        if (search_ctx->ffsc_start_dir == NULL)
            goto error_return;

#ifdef BACKSLASH_IN_FILENAME
        /* A path that starts with "/dir" is relative to the drive, not to the
         * directory (but not for "//machine/dir").  Only use the drive name. */
        if ((*path == '/' || *path == '\\')
                && path[1] != path[0]
                && search_ctx->ffsc_start_dir[1] == ':')
            search_ctx->ffsc_start_dir[2] = NUL;
#endif
    }

#ifdef FEAT_PATH_EXTRA
    /*
     * If stopdirs are given, split them into an array of pointers.
     * If this fails (mem allocation), there is no upward search at all or a
     * stop directory is not recognized -> continue silently.
     * If stopdirs just contains a ";" or is empty,
     * search_ctx->ffsc_stopdirs_v will only contain a  NULL pointer. This
     * is handled as unlimited upward search.  See function
     * ff_path_in_stoplist() for details.
     */
    if (stopdirs != NULL)
    {
        char_u  *walker = stopdirs;
        int     dircount;

        while (*walker == ';')
            walker++;

        dircount = 1;
        search_ctx->ffsc_stopdirs_v =
                                 (char_u **)alloc((unsigned)sizeof(char_u *));

        if (search_ctx->ffsc_stopdirs_v != NULL)
        {
            do
            {
                char_u  *helper;
                void    *ptr;

                helper = walker;
                ptr = vim_realloc(search_ctx->ffsc_stopdirs_v,
                                           (dircount + 1) * sizeof(char_u *));
                if (ptr)
                    search_ctx->ffsc_stopdirs_v = ptr;
                else
                    /* ignore, keep what we have and continue */
                    break;
                walker = vim_strchr(walker, ';');
                if (walker)
                {
                    search_ctx->ffsc_stopdirs_v[dircount-1] =
                                 vim_strnsave(helper, (int)(walker - helper));
                    walker++;
                }
                else
                    /* this might be "", which means ascent till top
                     * of directory tree.
                     */
                    search_ctx->ffsc_stopdirs_v[dircount-1] =
                                                          vim_strsave(helper);

                dircount++;

            } while (walker != NULL);
            search_ctx->ffsc_stopdirs_v[dircount-1] = NULL;
        }
    }
#endif

#ifdef FEAT_PATH_EXTRA
    search_ctx->ffsc_level = level;

    /* split into:
     *  -fix path
     *  -wildcard_stuff (might be NULL)
     */
    wc_part = vim_strchr(path, '*');
    if (wc_part != NULL)
    {
        int     llevel;
        int     len;
        char    *errpt;

        /* save the fix part of the path */
        search_ctx->ffsc_fix_path = vim_strnsave(path, (int)(wc_part - path));

        /*
         * copy wc_path and add restricts to the '**' wildcard.
         * The octet after a '**' is used as a (binary) counter.
         * So '**3' is transposed to '**^C' ('^C' is ASCII value 3)
         * or '**76' is transposed to '**N'( 'N' is ASCII value 76).
         * For EBCDIC you get different character values.
         * If no restrict is given after '**' the default is used.
         * Due to this technique the path looks awful if you print it as a
         * string.
         */
        len = 0;
        while (*wc_part != NUL)
        {
            if (STRNCMP(wc_part, "**", 2) == 0)
            {
                ff_expand_buffer[len++] = *wc_part++;
                ff_expand_buffer[len++] = *wc_part++;

                llevel = strtol((char *)wc_part, &errpt, 10);
                if ((char_u *)errpt != wc_part && llevel > 0 && llevel < 255)
                    ff_expand_buffer[len++] = llevel;
                else if ((char_u *)errpt != wc_part && llevel == 0)
                    /* restrict is 0 -> remove already added '**' */
                    len -= 2;
                else
                    ff_expand_buffer[len++] = FF_MAX_STAR_STAR_EXPAND;
                wc_part = (char_u *)errpt;
                if (*wc_part != NUL && !vim_ispathsep(*wc_part))
                {
                    EMSG2(_("E343: Invalid path: '**[number]' must be at the end of the path or be followed by '%s'."), PATHSEPSTR);
                    goto error_return;
                }
            }
            else
                ff_expand_buffer[len++] = *wc_part++;
        }
        ff_expand_buffer[len] = NUL;
        search_ctx->ffsc_wc_path = vim_strsave(ff_expand_buffer);

        if (search_ctx->ffsc_wc_path == NULL)
            goto error_return;
    }
    else
#endif
        search_ctx->ffsc_fix_path = vim_strsave(path);

    if (search_ctx->ffsc_start_dir == NULL)
    {
        /* store the fix part as startdir.
         * This is needed if the parameter path is fully qualified.
         */
        search_ctx->ffsc_start_dir = vim_strsave(search_ctx->ffsc_fix_path);
        if (search_ctx->ffsc_start_dir)
            search_ctx->ffsc_fix_path[0] = NUL;
    }

    /* create an absolute path */
    STRCPY(ff_expand_buffer, search_ctx->ffsc_start_dir);
    add_pathsep(ff_expand_buffer);
    STRCAT(ff_expand_buffer, search_ctx->ffsc_fix_path);
    add_pathsep(ff_expand_buffer);

    sptr = ff_create_stack_element(ff_expand_buffer,
#ifdef FEAT_PATH_EXTRA
            search_ctx->ffsc_wc_path,
#endif
            level, 0);

    if (sptr == NULL)
        goto error_return;

    ff_push(search_ctx, sptr);

    search_ctx->ffsc_file_to_search = vim_strsave(filename);
    if (search_ctx->ffsc_file_to_search == NULL)
        goto error_return;

    return search_ctx;

error_return:
    /*
     * We clear the search context now!
     * Even when the caller gave us a (perhaps valid) context we free it here,
     * as we might have already destroyed it.
     */
    vim_findfile_cleanup(search_ctx);
    return NULL;
}

#if defined(FEAT_PATH_EXTRA) || defined(PROTO)
/*
 * Get the stopdir string.  Check that ';' is not escaped.
 */
    char_u *
vim_findfile_stopdir(buf)
    char_u      *buf;
{
    char_u      *r_ptr = buf;

    while (*r_ptr != NUL && *r_ptr != ';')
    {
        if (r_ptr[0] == '\\' && r_ptr[1] == ';')
        {
            /* overwrite the escape char,
             * use STRLEN(r_ptr) to move the trailing '\0'
             */
            STRMOVE(r_ptr, r_ptr + 1);
            r_ptr++;
        }
        r_ptr++;
    }
    if (*r_ptr == ';')
    {
        *r_ptr = 0;
        r_ptr++;
    }
    else if (*r_ptr == NUL)
        r_ptr = NULL;
    return r_ptr;
}
#endif

/*
 * Clean up the given search context. Can handle a NULL pointer.
 */
    void
vim_findfile_cleanup(ctx)
    void        *ctx;
{
    if (ctx == NULL)
        return;

    vim_findfile_free_visited(ctx);
    ff_clear(ctx);
    vim_free(ctx);
}

/*
 * Find a file in a search context.
 * The search context was created with vim_findfile_init() above.
 * Return a pointer to an allocated file name or NULL if nothing found.
 * To get all matching files call this function until you get NULL.
 *
 * If the passed search_context is NULL, NULL is returned.
 *
 * The search algorithm is depth first. To change this replace the
 * stack with a list (don't forget to leave partly searched directories on the
 * top of the list).
 */
    char_u *
vim_findfile(search_ctx_arg)
    void        *search_ctx_arg;
{
    char_u      *file_path;
#ifdef FEAT_PATH_EXTRA
    char_u      *rest_of_wildcards;
    char_u      *path_end = NULL;
#endif
    ff_stack_T  *stackp;
#if defined(FEAT_SEARCHPATH) || defined(FEAT_PATH_EXTRA)
    int         len;
#endif
    int         i;
    char_u      *p;
#ifdef FEAT_SEARCHPATH
    char_u      *suf;
#endif
    ff_search_ctx_T *search_ctx;

    if (search_ctx_arg == NULL)
        return NULL;

    search_ctx = (ff_search_ctx_T *)search_ctx_arg;

    /*
     * filepath is used as buffer for various actions and as the storage to
     * return a found filename.
     */
    if ((file_path = alloc((int)MAXPATHL)) == NULL)
        return NULL;

#ifdef FEAT_PATH_EXTRA
    /* store the end of the start dir -- needed for upward search */
    if (search_ctx->ffsc_start_dir != NULL)
        path_end = &search_ctx->ffsc_start_dir[
                                          STRLEN(search_ctx->ffsc_start_dir)];
#endif

#ifdef FEAT_PATH_EXTRA
    /* upward search loop */
    for (;;)
    {
#endif
        /* downward search loop */
        for (;;)
        {
            /* check if user user wants to stop the search*/
            ui_breakcheck();
            if (got_int)
                break;

            /* get directory to work on from stack */
            stackp = ff_pop(search_ctx);
            if (stackp == NULL)
                break;

            /*
             * TODO: decide if we leave this test in
             *
             * GOOD: don't search a directory(-tree) twice.
             * BAD:  - check linked list for every new directory entered.
             *       - check for double files also done below
             *
             * Here we check if we already searched this directory.
             * We already searched a directory if:
             * 1) The directory is the same.
             * 2) We would use the same wildcard string.
             *
             * Good if you have links on same directory via several ways
             *  or you have selfreferences in directories (e.g. SuSE Linux 6.3:
             *  /etc/rc.d/init.d is linked to /etc/rc.d -> endless loop)
             *
             * This check is only needed for directories we work on for the
             * first time (hence stackp->ff_filearray == NULL)
             */
            if (stackp->ffs_filearray == NULL
                    && ff_check_visited(&search_ctx->ffsc_dir_visited_list
                                                          ->ffvl_visited_list,
                        stackp->ffs_fix_path
#ifdef FEAT_PATH_EXTRA
                        , stackp->ffs_wc_path
#endif
                        ) == FAIL)
            {
#ifdef FF_VERBOSE
                if (p_verbose >= 5)
                {
                    verbose_enter_scroll();
                    smsg((char_u *)"Already Searched: %s (%s)",
                                   stackp->ffs_fix_path, stackp->ffs_wc_path);
                    /* don't overwrite this either */
                    msg_puts((char_u *)"\n");
                    verbose_leave_scroll();
                }
#endif
                ff_free_stack_element(stackp);
                continue;
            }
#ifdef FF_VERBOSE
            else if (p_verbose >= 5)
            {
                verbose_enter_scroll();
                smsg((char_u *)"Searching: %s (%s)",
                                   stackp->ffs_fix_path, stackp->ffs_wc_path);
                /* don't overwrite this either */
                msg_puts((char_u *)"\n");
                verbose_leave_scroll();
            }
#endif

            /* check depth */
            if (stackp->ffs_level <= 0)
            {
                ff_free_stack_element(stackp);
                continue;
            }

            file_path[0] = NUL;

            /*
             * If no filearray till now expand wildcards
             * The function expand_wildcards() can handle an array of paths
             * and all possible expands are returned in one array. We use this
             * to handle the expansion of '**' into an empty string.
             */
            if (stackp->ffs_filearray == NULL)
            {
                char_u *dirptrs[2];

                /* we use filepath to build the path expand_wildcards() should
                 * expand.
                 */
                dirptrs[0] = file_path;
                dirptrs[1] = NULL;

                /* if we have a start dir copy it in */
                if (!vim_isAbsName(stackp->ffs_fix_path)
                                                && search_ctx->ffsc_start_dir)
                {
                    STRCPY(file_path, search_ctx->ffsc_start_dir);
                    add_pathsep(file_path);
                }

                /* append the fix part of the search path */
                STRCAT(file_path, stackp->ffs_fix_path);
                add_pathsep(file_path);

#ifdef FEAT_PATH_EXTRA
                rest_of_wildcards = stackp->ffs_wc_path;
                if (*rest_of_wildcards != NUL)
                {
                    len = (int)STRLEN(file_path);
                    if (STRNCMP(rest_of_wildcards, "**", 2) == 0)
                    {
                        /* pointer to the restrict byte
                         * The restrict byte is not a character!
                         */
                        p = rest_of_wildcards + 2;

                        if (*p > 0)
                        {
                            (*p)--;
                            file_path[len++] = '*';
                        }

                        if (*p == 0)
                        {
                            /* remove '**<numb> from wildcards */
                            STRMOVE(rest_of_wildcards, rest_of_wildcards + 3);
                        }
                        else
                            rest_of_wildcards += 3;

                        if (stackp->ffs_star_star_empty == 0)
                        {
                            /* if not done before, expand '**' to empty */
                            stackp->ffs_star_star_empty = 1;
                            dirptrs[1] = stackp->ffs_fix_path;
                        }
                    }

                    /*
                     * Here we copy until the next path separator or the end of
                     * the path. If we stop at a path separator, there is
                     * still something else left. This is handled below by
                     * pushing every directory returned from expand_wildcards()
                     * on the stack again for further search.
                     */
                    while (*rest_of_wildcards
                            && !vim_ispathsep(*rest_of_wildcards))
                        file_path[len++] = *rest_of_wildcards++;

                    file_path[len] = NUL;
                    if (vim_ispathsep(*rest_of_wildcards))
                        rest_of_wildcards++;
                }
#endif

                /*
                 * Expand wildcards like "*" and "$VAR".
                 * If the path is a URL don't try this.
                 */
                if (path_with_url(dirptrs[0]))
                {
                    stackp->ffs_filearray = (char_u **)
                                              alloc((unsigned)sizeof(char *));
                    if (stackp->ffs_filearray != NULL
                            && (stackp->ffs_filearray[0]
                                = vim_strsave(dirptrs[0])) != NULL)
                        stackp->ffs_filearray_size = 1;
                    else
                        stackp->ffs_filearray_size = 0;
                }
                else
                    expand_wildcards((dirptrs[1] == NULL) ? 1 : 2, dirptrs,
                            &stackp->ffs_filearray_size,
                            &stackp->ffs_filearray,
                            EW_DIR|EW_ADDSLASH|EW_SILENT);

                stackp->ffs_filearray_cur = 0;
                stackp->ffs_stage = 0;
            }
#ifdef FEAT_PATH_EXTRA
            else
                rest_of_wildcards = &stackp->ffs_wc_path[
                                                 STRLEN(stackp->ffs_wc_path)];
#endif

            if (stackp->ffs_stage == 0)
            {
                /* this is the first time we work on this directory */
#ifdef FEAT_PATH_EXTRA
                if (*rest_of_wildcards == NUL)
#endif
                {
                    /*
                     * we don't have further wildcards to expand, so we have to
                     * check for the final file now
                     */
                    for (i = stackp->ffs_filearray_cur;
                                          i < stackp->ffs_filearray_size; ++i)
                    {
                        if (!path_with_url(stackp->ffs_filearray[i])
                                      && !mch_isdir(stackp->ffs_filearray[i]))
                            continue;   /* not a directory */

                        /* prepare the filename to be checked for existence
                         * below */
                        STRCPY(file_path, stackp->ffs_filearray[i]);
                        add_pathsep(file_path);
                        STRCAT(file_path, search_ctx->ffsc_file_to_search);

                        /*
                         * Try without extra suffix and then with suffixes
                         * from 'suffixesadd'.
                         */
#ifdef FEAT_SEARCHPATH
                        len = (int)STRLEN(file_path);
                        suf = curbuf->b_p_sua;
                        for (;;)
#endif
                        {
                            /* if file exists and we didn't already find it */
                            if ((path_with_url(file_path)
                                  || (mch_getperm(file_path) >= 0
                                      && (search_ctx->ffsc_find_what
                                                              == FINDFILE_BOTH
                                          || ((search_ctx->ffsc_find_what
                                                              == FINDFILE_DIR)
                                                   == mch_isdir(file_path)))))
#ifndef FF_VERBOSE
                                    && (ff_check_visited(
                                            &search_ctx->ffsc_visited_list->ffvl_visited_list,
                                            file_path
#ifdef FEAT_PATH_EXTRA
                                            , (char_u *)""
#endif
                                            ) == OK)
#endif
                               )
                            {
#ifdef FF_VERBOSE
                                if (ff_check_visited(
                                            &search_ctx->ffsc_visited_list->ffvl_visited_list,
                                            file_path
#ifdef FEAT_PATH_EXTRA
                                            , (char_u *)""
#endif
                                                    ) == FAIL)
                                {
                                    if (p_verbose >= 5)
                                    {
                                        verbose_enter_scroll();
                                        smsg((char_u *)"Already: %s",
                                                                   file_path);
                                        /* don't overwrite this either */
                                        msg_puts((char_u *)"\n");
                                        verbose_leave_scroll();
                                    }
                                    continue;
                                }
#endif

                                /* push dir to examine rest of subdirs later */
                                stackp->ffs_filearray_cur = i + 1;
                                ff_push(search_ctx, stackp);

                                if (!path_with_url(file_path))
                                    simplify_filename(file_path);
                                if (mch_dirname(ff_expand_buffer, MAXPATHL)
                                                                        == OK)
                                {
                                    p = shorten_fname(file_path,
                                                            ff_expand_buffer);
                                    if (p != NULL)
                                        STRMOVE(file_path, p);
                                }
#ifdef FF_VERBOSE
                                if (p_verbose >= 5)
                                {
                                    verbose_enter_scroll();
                                    smsg((char_u *)"HIT: %s", file_path);
                                    /* don't overwrite this either */
                                    msg_puts((char_u *)"\n");
                                    verbose_leave_scroll();
                                }
#endif
                                return file_path;
                            }

#ifdef FEAT_SEARCHPATH
                            /* Not found or found already, try next suffix. */
                            if (*suf == NUL)
                                break;
                            copy_option_part(&suf, file_path + len,
                                                         MAXPATHL - len, ",");
#endif
                        }
                    }
                }
#ifdef FEAT_PATH_EXTRA
                else
                {
                    /*
                     * still wildcards left, push the directories for further
                     * search
                     */
                    for (i = stackp->ffs_filearray_cur;
                                          i < stackp->ffs_filearray_size; ++i)
                    {
                        if (!mch_isdir(stackp->ffs_filearray[i]))
                            continue;   /* not a directory */

                        ff_push(search_ctx,
                                ff_create_stack_element(
                                                     stackp->ffs_filearray[i],
                                                     rest_of_wildcards,
                                                     stackp->ffs_level - 1, 0));
                    }
                }
#endif
                stackp->ffs_filearray_cur = 0;
                stackp->ffs_stage = 1;
            }

#ifdef FEAT_PATH_EXTRA
            /*
             * if wildcards contains '**' we have to descent till we reach the
             * leaves of the directory tree.
             */
            if (STRNCMP(stackp->ffs_wc_path, "**", 2) == 0)
            {
                for (i = stackp->ffs_filearray_cur;
                                          i < stackp->ffs_filearray_size; ++i)
                {
                    if (fnamecmp(stackp->ffs_filearray[i],
                                                   stackp->ffs_fix_path) == 0)
                        continue; /* don't repush same directory */
                    if (!mch_isdir(stackp->ffs_filearray[i]))
                        continue;   /* not a directory */
                    ff_push(search_ctx,
                            ff_create_stack_element(stackp->ffs_filearray[i],
                                stackp->ffs_wc_path, stackp->ffs_level - 1, 1));
                }
            }
#endif

            /* we are done with the current directory */
            ff_free_stack_element(stackp);

        }

#ifdef FEAT_PATH_EXTRA
        /* If we reached this, we didn't find anything downwards.
         * Let's check if we should do an upward search.
         */
        if (search_ctx->ffsc_start_dir
                && search_ctx->ffsc_stopdirs_v != NULL && !got_int)
        {
            ff_stack_T  *sptr;

            /* is the last starting directory in the stop list? */
            if (ff_path_in_stoplist(search_ctx->ffsc_start_dir,
                       (int)(path_end - search_ctx->ffsc_start_dir),
                       search_ctx->ffsc_stopdirs_v) == TRUE)
                break;

            /* cut of last dir */
            while (path_end > search_ctx->ffsc_start_dir
                                                  && vim_ispathsep(*path_end))
                path_end--;
            while (path_end > search_ctx->ffsc_start_dir
                                              && !vim_ispathsep(path_end[-1]))
                path_end--;
            *path_end = 0;
            path_end--;

            if (*search_ctx->ffsc_start_dir == 0)
                break;

            STRCPY(file_path, search_ctx->ffsc_start_dir);
            add_pathsep(file_path);
            STRCAT(file_path, search_ctx->ffsc_fix_path);

            /* create a new stack entry */
            sptr = ff_create_stack_element(file_path,
                    search_ctx->ffsc_wc_path, search_ctx->ffsc_level, 0);
            if (sptr == NULL)
                break;
            ff_push(search_ctx, sptr);
        }
        else
            break;
    }
#endif

    vim_free(file_path);
    return NULL;
}

/*
 * Free the list of lists of visited files and directories
 * Can handle it if the passed search_context is NULL;
 */
    void
vim_findfile_free_visited(search_ctx_arg)
    void        *search_ctx_arg;
{
    ff_search_ctx_T *search_ctx;

    if (search_ctx_arg == NULL)
        return;

    search_ctx = (ff_search_ctx_T *)search_ctx_arg;
    vim_findfile_free_visited_list(&search_ctx->ffsc_visited_lists_list);
    vim_findfile_free_visited_list(&search_ctx->ffsc_dir_visited_lists_list);
}

    static void
vim_findfile_free_visited_list(list_headp)
    ff_visited_list_hdr_T       **list_headp;
{
    ff_visited_list_hdr_T *vp;

    while (*list_headp != NULL)
    {
        vp = (*list_headp)->ffvl_next;
        ff_free_visited_list((*list_headp)->ffvl_visited_list);

        vim_free((*list_headp)->ffvl_filename);
        vim_free(*list_headp);
        *list_headp = vp;
    }
    *list_headp = NULL;
}

    static void
ff_free_visited_list(vl)
    ff_visited_T *vl;
{
    ff_visited_T *vp;

    while (vl != NULL)
    {
        vp = vl->ffv_next;
#ifdef FEAT_PATH_EXTRA
        vim_free(vl->ffv_wc_path);
#endif
        vim_free(vl);
        vl = vp;
    }
    vl = NULL;
}

/*
 * Returns the already visited list for the given filename. If none is found it
 * allocates a new one.
 */
    static ff_visited_list_hdr_T*
ff_get_visited_list(filename, list_headp)
    char_u                      *filename;
    ff_visited_list_hdr_T       **list_headp;
{
    ff_visited_list_hdr_T  *retptr = NULL;

    /* check if a visited list for the given filename exists */
    if (*list_headp != NULL)
    {
        retptr = *list_headp;
        while (retptr != NULL)
        {
            if (fnamecmp(filename, retptr->ffvl_filename) == 0)
            {
#ifdef FF_VERBOSE
                if (p_verbose >= 5)
                {
                    verbose_enter_scroll();
                    smsg((char_u *)"ff_get_visited_list: FOUND list for %s",
                                                                    filename);
                    /* don't overwrite this either */
                    msg_puts((char_u *)"\n");
                    verbose_leave_scroll();
                }
#endif
                return retptr;
            }
            retptr = retptr->ffvl_next;
        }
    }

#ifdef FF_VERBOSE
    if (p_verbose >= 5)
    {
        verbose_enter_scroll();
        smsg((char_u *)"ff_get_visited_list: new list for %s", filename);
        /* don't overwrite this either */
        msg_puts((char_u *)"\n");
        verbose_leave_scroll();
    }
#endif

    /*
     * if we reach this we didn't find a list and we have to allocate new list
     */
    retptr = (ff_visited_list_hdr_T*)alloc((unsigned)sizeof(*retptr));
    if (retptr == NULL)
        return NULL;

    retptr->ffvl_visited_list = NULL;
    retptr->ffvl_filename = vim_strsave(filename);
    if (retptr->ffvl_filename == NULL)
    {
        vim_free(retptr);
        return NULL;
    }
    retptr->ffvl_next = *list_headp;
    *list_headp = retptr;

    return retptr;
}

#ifdef FEAT_PATH_EXTRA
/*
 * check if two wildcard paths are equal. Returns TRUE or FALSE.
 * They are equal if:
 *  - both paths are NULL
 *  - they have the same length
 *  - char by char comparison is OK
 *  - the only differences are in the counters behind a '**', so
 *    '**\20' is equal to '**\24'
 */
    static int
ff_wc_equal(s1, s2)
    char_u      *s1;
    char_u      *s2;
{
    int         i;

    if (s1 == s2)
        return TRUE;

    if (s1 == NULL || s2 == NULL)
        return FALSE;

    if (STRLEN(s1) != STRLEN(s2))
        return FAIL;

    for (i = 0; s1[i] != NUL && s2[i] != NUL; i++)
    {
        if (s1[i] != s2[i]
#ifdef CASE_INSENSITIVE_FILENAME
                && TOUPPER_LOC(s1[i]) != TOUPPER_LOC(s2[i])
#endif
                )
        {
            if (i >= 2)
                if (s1[i-1] == '*' && s1[i-2] == '*')
                    continue;
                else
                    return FAIL;
            else
                return FAIL;
        }
    }
    return TRUE;
}
#endif

/*
 * maintains the list of already visited files and dirs
 * returns FAIL if the given file/dir is already in the list
 * returns OK if it is newly added
 *
 * TODO: What to do on memory allocation problems?
 *       -> return TRUE - Better the file is found several times instead of
 *          never.
 */
    static int
ff_check_visited(visited_list, fname
#ifdef FEAT_PATH_EXTRA
        , wc_path
#endif
        )
    ff_visited_T        **visited_list;
    char_u              *fname;
#ifdef FEAT_PATH_EXTRA
    char_u              *wc_path;
#endif
{
    ff_visited_T        *vp;
#ifdef UNIX
    struct stat         st;
    int                 url = FALSE;
#endif

    /* For an URL we only compare the name, otherwise we compare the
     * device/inode (unix) or the full path name (not Unix). */
    if (path_with_url(fname))
    {
        vim_strncpy(ff_expand_buffer, fname, MAXPATHL - 1);
#ifdef UNIX
        url = TRUE;
#endif
    }
    else
    {
        ff_expand_buffer[0] = NUL;
#ifdef UNIX
        if (mch_stat((char *)fname, &st) < 0)
#else
        if (vim_FullName(fname, ff_expand_buffer, MAXPATHL, TRUE) == FAIL)
#endif
            return FAIL;
    }

    /* check against list of already visited files */
    for (vp = *visited_list; vp != NULL; vp = vp->ffv_next)
    {
        if (
#ifdef UNIX
                !url ? (vp->ffv_dev_valid && vp->ffv_dev == st.st_dev
                                                  && vp->ffv_ino == st.st_ino)
                     :
#endif
                fnamecmp(vp->ffv_fname, ff_expand_buffer) == 0
           )
        {
#ifdef FEAT_PATH_EXTRA
            /* are the wildcard parts equal */
            if (ff_wc_equal(vp->ffv_wc_path, wc_path) == TRUE)
#endif
                /* already visited */
                return FAIL;
        }
    }

    /*
     * New file/dir.  Add it to the list of visited files/dirs.
     */
    vp = (ff_visited_T *)alloc((unsigned)(sizeof(ff_visited_T)
                                                 + STRLEN(ff_expand_buffer)));

    if (vp != NULL)
    {
#ifdef UNIX
        if (!url)
        {
            vp->ffv_dev_valid = TRUE;
            vp->ffv_ino = st.st_ino;
            vp->ffv_dev = st.st_dev;
            vp->ffv_fname[0] = NUL;
        }
        else
        {
            vp->ffv_dev_valid = FALSE;
#endif
            STRCPY(vp->ffv_fname, ff_expand_buffer);
#ifdef UNIX
        }
#endif
#ifdef FEAT_PATH_EXTRA
        if (wc_path != NULL)
            vp->ffv_wc_path = vim_strsave(wc_path);
        else
            vp->ffv_wc_path = NULL;
#endif

        vp->ffv_next = *visited_list;
        *visited_list = vp;
    }

    return OK;
}

/*
 * create stack element from given path pieces
 */
    static ff_stack_T *
ff_create_stack_element(fix_part,
#ifdef FEAT_PATH_EXTRA
        wc_part,
#endif
        level, star_star_empty)
    char_u      *fix_part;
#ifdef FEAT_PATH_EXTRA
    char_u      *wc_part;
#endif
    int         level;
    int         star_star_empty;
{
    ff_stack_T  *new;

    new = (ff_stack_T *)alloc((unsigned)sizeof(ff_stack_T));
    if (new == NULL)
        return NULL;

    new->ffs_prev          = NULL;
    new->ffs_filearray     = NULL;
    new->ffs_filearray_size = 0;
    new->ffs_filearray_cur  = 0;
    new->ffs_stage         = 0;
    new->ffs_level         = level;
    new->ffs_star_star_empty = star_star_empty;;

    /* the following saves NULL pointer checks in vim_findfile */
    if (fix_part == NULL)
        fix_part = (char_u *)"";
    new->ffs_fix_path = vim_strsave(fix_part);

#ifdef FEAT_PATH_EXTRA
    if (wc_part == NULL)
        wc_part  = (char_u *)"";
    new->ffs_wc_path = vim_strsave(wc_part);
#endif

    if (new->ffs_fix_path == NULL
#ifdef FEAT_PATH_EXTRA
            || new->ffs_wc_path == NULL
#endif
            )
    {
        ff_free_stack_element(new);
        new = NULL;
    }

    return new;
}

/*
 * Push a dir on the directory stack.
 */
    static void
ff_push(search_ctx, stack_ptr)
    ff_search_ctx_T *search_ctx;
    ff_stack_T      *stack_ptr;
{
    /* check for NULL pointer, not to return an error to the user, but
     * to prevent a crash */
    if (stack_ptr != NULL)
    {
        stack_ptr->ffs_prev = search_ctx->ffsc_stack_ptr;
        search_ctx->ffsc_stack_ptr = stack_ptr;
    }
}

/*
 * Pop a dir from the directory stack.
 * Returns NULL if stack is empty.
 */
    static ff_stack_T *
ff_pop(search_ctx)
    ff_search_ctx_T *search_ctx;
{
    ff_stack_T  *sptr;

    sptr = search_ctx->ffsc_stack_ptr;
    if (search_ctx->ffsc_stack_ptr != NULL)
        search_ctx->ffsc_stack_ptr = search_ctx->ffsc_stack_ptr->ffs_prev;

    return sptr;
}

/*
 * free the given stack element
 */
    static void
ff_free_stack_element(stack_ptr)
    ff_stack_T  *stack_ptr;
{
    /* vim_free handles possible NULL pointers */
    vim_free(stack_ptr->ffs_fix_path);
#ifdef FEAT_PATH_EXTRA
    vim_free(stack_ptr->ffs_wc_path);
#endif

    if (stack_ptr->ffs_filearray != NULL)
        FreeWild(stack_ptr->ffs_filearray_size, stack_ptr->ffs_filearray);

    vim_free(stack_ptr);
}

/*
 * Clear the search context, but NOT the visited list.
 */
    static void
ff_clear(search_ctx)
    ff_search_ctx_T *search_ctx;
{
    ff_stack_T   *sptr;

    /* clear up stack */
    while ((sptr = ff_pop(search_ctx)) != NULL)
        ff_free_stack_element(sptr);

    vim_free(search_ctx->ffsc_file_to_search);
    vim_free(search_ctx->ffsc_start_dir);
    vim_free(search_ctx->ffsc_fix_path);
#ifdef FEAT_PATH_EXTRA
    vim_free(search_ctx->ffsc_wc_path);
#endif

#ifdef FEAT_PATH_EXTRA
    if (search_ctx->ffsc_stopdirs_v != NULL)
    {
        int  i = 0;

        while (search_ctx->ffsc_stopdirs_v[i] != NULL)
        {
            vim_free(search_ctx->ffsc_stopdirs_v[i]);
            i++;
        }
        vim_free(search_ctx->ffsc_stopdirs_v);
    }
    search_ctx->ffsc_stopdirs_v = NULL;
#endif

    /* reset everything */
    search_ctx->ffsc_file_to_search = NULL;
    search_ctx->ffsc_start_dir = NULL;
    search_ctx->ffsc_fix_path = NULL;
#ifdef FEAT_PATH_EXTRA
    search_ctx->ffsc_wc_path = NULL;
    search_ctx->ffsc_level = 0;
#endif
}

#ifdef FEAT_PATH_EXTRA
/*
 * check if the given path is in the stopdirs
 * returns TRUE if yes else FALSE
 */
    static int
ff_path_in_stoplist(path, path_len, stopdirs_v)
    char_u      *path;
    int         path_len;
    char_u      **stopdirs_v;
{
    int         i = 0;

    /* eat up trailing path separators, except the first */
    while (path_len > 1 && vim_ispathsep(path[path_len - 1]))
        path_len--;

    /* if no path consider it as match */
    if (path_len == 0)
        return TRUE;

    for (i = 0; stopdirs_v[i] != NULL; i++)
    {
        if ((int)STRLEN(stopdirs_v[i]) > path_len)
        {
            /* match for parent directory. So '/home' also matches
             * '/home/rks'. Check for PATHSEP in stopdirs_v[i], else
             * '/home/r' would also match '/home/rks'
             */
            if (fnamencmp(stopdirs_v[i], path, path_len) == 0
                    && vim_ispathsep(stopdirs_v[i][path_len]))
                return TRUE;
        }
        else
        {
            if (fnamecmp(stopdirs_v[i], path) == 0)
                return TRUE;
        }
    }
    return FALSE;
}
#endif

#if defined(FEAT_SEARCHPATH) || defined(PROTO)
/*
 * Find the file name "ptr[len]" in the path.  Also finds directory names.
 *
 * On the first call set the parameter 'first' to TRUE to initialize
 * the search.  For repeating calls to FALSE.
 *
 * Repeating calls will return other files called 'ptr[len]' from the path.
 *
 * Only on the first call 'ptr' and 'len' are used.  For repeating calls they
 * don't need valid values.
 *
 * If nothing found on the first call the option FNAME_MESS will issue the
 * message:
 *          'Can't find file "<file>" in path'
 * On repeating calls:
 *          'No more file "<file>" found in path'
 *
 * options:
 * FNAME_MESS       give error message when not found
 *
 * Uses NameBuff[]!
 *
 * Returns an allocated string for the file name.  NULL for error.
 *
 */
    char_u *
find_file_in_path(ptr, len, options, first, rel_fname)
    char_u      *ptr;           /* file name */
    int         len;            /* length of file name */
    int         options;
    int         first;          /* use count'th matching file name */
    char_u      *rel_fname;     /* file name searching relative to */
{
    return find_file_in_path_option(ptr, len, options, first,
            *curbuf->b_p_path == NUL ? p_path : curbuf->b_p_path,
            FINDFILE_BOTH, rel_fname, curbuf->b_p_sua);
}

static char_u   *ff_file_to_find = NULL;
static void     *fdip_search_ctx = NULL;

#if defined(EXITFREE)
    static void
free_findfile()
{
    vim_free(ff_file_to_find);
    vim_findfile_cleanup(fdip_search_ctx);
}
#endif

/*
 * Find the directory name "ptr[len]" in the path.
 *
 * options:
 * FNAME_MESS       give error message when not found
 *
 * Uses NameBuff[]!
 *
 * Returns an allocated string for the file name.  NULL for error.
 */
    char_u *
find_directory_in_path(ptr, len, options, rel_fname)
    char_u      *ptr;           /* file name */
    int         len;            /* length of file name */
    int         options;
    char_u      *rel_fname;     /* file name searching relative to */
{
    return find_file_in_path_option(ptr, len, options, TRUE, p_cdpath,
                                       FINDFILE_DIR, rel_fname, (char_u *)"");
}

    char_u *
find_file_in_path_option(ptr, len, options, first, path_option, find_what, rel_fname, suffixes)
    char_u      *ptr;           /* file name */
    int         len;            /* length of file name */
    int         options;
    int         first;          /* use count'th matching file name */
    char_u      *path_option;   /* p_path or p_cdpath */
    int         find_what;      /* FINDFILE_FILE, _DIR or _BOTH */
    char_u      *rel_fname;     /* file name we are looking relative to. */
    char_u      *suffixes;      /* list of suffixes, 'suffixesadd' option */
{
    static char_u       *dir;
    static int          did_findfile_init = FALSE;
    char_u              save_char;
    char_u              *file_name = NULL;
    char_u              *buf = NULL;
    int                 rel_to_curdir;
#ifdef AMIGA
    struct Process      *proc = (struct Process *)FindTask(0L);
    APTR                save_winptr = proc->pr_WindowPtr;

    /* Avoid a requester here for a volume that doesn't exist. */
    proc->pr_WindowPtr = (APTR)-1L;
#endif

    if (first == TRUE)
    {
        /* copy file name into NameBuff, expanding environment variables */
        save_char = ptr[len];
        ptr[len] = NUL;
        expand_env(ptr, NameBuff, MAXPATHL);
        ptr[len] = save_char;

        vim_free(ff_file_to_find);
        ff_file_to_find = vim_strsave(NameBuff);
        if (ff_file_to_find == NULL)    /* out of memory */
        {
            file_name = NULL;
            goto theend;
        }
    }

    rel_to_curdir = (ff_file_to_find[0] == '.'
                    && (ff_file_to_find[1] == NUL
                        || vim_ispathsep(ff_file_to_find[1])
                        || (ff_file_to_find[1] == '.'
                            && (ff_file_to_find[2] == NUL
                                || vim_ispathsep(ff_file_to_find[2])))));
    if (vim_isAbsName(ff_file_to_find)
            /* "..", "../path", "." and "./path": don't use the path_option */
            || rel_to_curdir
#if defined(MSWIN) || defined(MSDOS) || defined(OS2)
            /* handle "\tmp" as absolute path */
            || vim_ispathsep(ff_file_to_find[0])
            /* handle "c:name" as absolute path */
            || (ff_file_to_find[0] != NUL && ff_file_to_find[1] == ':')
#endif
#ifdef AMIGA
            /* handle ":tmp" as absolute path */
            || ff_file_to_find[0] == ':'
#endif
       )
    {
        /*
         * Absolute path, no need to use "path_option".
         * If this is not a first call, return NULL.  We already returned a
         * filename on the first call.
         */
        if (first == TRUE)
        {
            int         l;
            int         run;

            if (path_with_url(ff_file_to_find))
            {
                file_name = vim_strsave(ff_file_to_find);
                goto theend;
            }

            /* When FNAME_REL flag given first use the directory of the file.
             * Otherwise or when this fails use the current directory. */
            for (run = 1; run <= 2; ++run)
            {
                l = (int)STRLEN(ff_file_to_find);
                if (run == 1
                        && rel_to_curdir
                        && (options & FNAME_REL)
                        && rel_fname != NULL
                        && STRLEN(rel_fname) + l < MAXPATHL)
                {
                    STRCPY(NameBuff, rel_fname);
                    STRCPY(gettail(NameBuff), ff_file_to_find);
                    l = (int)STRLEN(NameBuff);
                }
                else
                {
                    STRCPY(NameBuff, ff_file_to_find);
                    run = 2;
                }

                /* When the file doesn't exist, try adding parts of
                 * 'suffixesadd'. */
                buf = suffixes;
                for (;;)
                {
                    if (
#ifdef DJGPP
                            /* "C:" by itself will fail for mch_getperm(),
                             * assume it's always valid. */
                            (find_what != FINDFILE_FILE && NameBuff[0] != NUL
                                  && NameBuff[1] == ':'
                                  && NameBuff[2] == NUL) ||
#endif
                            (mch_getperm(NameBuff) >= 0
                             && (find_what == FINDFILE_BOTH
                                 || ((find_what == FINDFILE_DIR)
                                                    == mch_isdir(NameBuff)))))
                    {
                        file_name = vim_strsave(NameBuff);
                        goto theend;
                    }
                    if (*buf == NUL)
                        break;
                    copy_option_part(&buf, NameBuff + l, MAXPATHL - l, ",");
                }
            }
        }
    }
    else
    {
        /*
         * Loop over all paths in the 'path' or 'cdpath' option.
         * When "first" is set, first setup to the start of the option.
         * Otherwise continue to find the next match.
         */
        if (first == TRUE)
        {
            /* vim_findfile_free_visited can handle a possible NULL pointer */
            vim_findfile_free_visited(fdip_search_ctx);
            dir = path_option;
            did_findfile_init = FALSE;
        }

        for (;;)
        {
            if (did_findfile_init)
            {
                file_name = vim_findfile(fdip_search_ctx);
                if (file_name != NULL)
                    break;

                did_findfile_init = FALSE;
            }
            else
            {
                char_u  *r_ptr;

                if (dir == NULL || *dir == NUL)
                {
                    /* We searched all paths of the option, now we can
                     * free the search context. */
                    vim_findfile_cleanup(fdip_search_ctx);
                    fdip_search_ctx = NULL;
                    break;
                }

                if ((buf = alloc((int)(MAXPATHL))) == NULL)
                    break;

                /* copy next path */
                buf[0] = 0;
                copy_option_part(&dir, buf, MAXPATHL, " ,");

#ifdef FEAT_PATH_EXTRA
                /* get the stopdir string */
                r_ptr = vim_findfile_stopdir(buf);
#else
                r_ptr = NULL;
#endif
                fdip_search_ctx = vim_findfile_init(buf, ff_file_to_find,
                                            r_ptr, 100, FALSE, find_what,
                                           fdip_search_ctx, FALSE, rel_fname);
                if (fdip_search_ctx != NULL)
                    did_findfile_init = TRUE;
                vim_free(buf);
            }
        }
    }
    if (file_name == NULL && (options & FNAME_MESS))
    {
        if (first == TRUE)
        {
            if (find_what == FINDFILE_DIR)
                EMSG2(_("E344: Can't find directory \"%s\" in cdpath"),
                        ff_file_to_find);
            else
                EMSG2(_("E345: Can't find file \"%s\" in path"),
                        ff_file_to_find);
        }
        else
        {
            if (find_what == FINDFILE_DIR)
                EMSG2(_("E346: No more directory \"%s\" found in cdpath"),
                        ff_file_to_find);
            else
                EMSG2(_("E347: No more file \"%s\" found in path"),
                        ff_file_to_find);
        }
    }

theend:
#ifdef AMIGA
    proc->pr_WindowPtr = save_winptr;
#endif
    return file_name;
}

#endif /* FEAT_SEARCHPATH */

/*
 * Change directory to "new_dir".  If FEAT_SEARCHPATH is defined, search
 * 'cdpath' for relative directory names, otherwise just mch_chdir().
 */
    int
vim_chdir(new_dir)
    char_u      *new_dir;
{
#ifndef FEAT_SEARCHPATH
    return mch_chdir((char *)new_dir);
#else
    char_u      *dir_name;
    int         r;

    dir_name = find_directory_in_path(new_dir, (int)STRLEN(new_dir),
                                                FNAME_MESS, curbuf->b_ffname);
    if (dir_name == NULL)
        return -1;
    r = mch_chdir((char *)dir_name);
    vim_free(dir_name);
    return r;
#endif
}

/*
 * Get user name from machine-specific function.
 * Returns the user name in "buf[len]".
 * Some systems are quite slow in obtaining the user name (Windows NT), thus
 * cache the result.
 * Returns OK or FAIL.
 */
    int
get_user_name(buf, len)
    char_u      *buf;
    int         len;
{
    if (username == NULL)
    {
        if (mch_get_user_name(buf, len) == FAIL)
            return FAIL;
        username = vim_strsave(buf);
    }
    else
        vim_strncpy(buf, username, len - 1);
    return OK;
}

#ifndef HAVE_QSORT
/*
 * Our own qsort(), for systems that don't have it.
 * It's simple and slow.  From the K&R C book.
 */
    void
qsort(base, elm_count, elm_size, cmp)
    void        *base;
    size_t      elm_count;
    size_t      elm_size;
    int (*cmp) __ARGS((const void *, const void *));
{
    char_u      *buf;
    char_u      *p1;
    char_u      *p2;
    int         i, j;
    int         gap;

    buf = alloc((unsigned)elm_size);
    if (buf == NULL)
        return;

    for (gap = elm_count / 2; gap > 0; gap /= 2)
        for (i = gap; i < elm_count; ++i)
            for (j = i - gap; j >= 0; j -= gap)
            {
                /* Compare the elements. */
                p1 = (char_u *)base + j * elm_size;
                p2 = (char_u *)base + (j + gap) * elm_size;
                if ((*cmp)((void *)p1, (void *)p2) <= 0)
                    break;
                /* Exchange the elements. */
                mch_memmove(buf, p1, elm_size);
                mch_memmove(p1, p2, elm_size);
                mch_memmove(p2, buf, elm_size);
            }

    vim_free(buf);
}
#endif

/*
 * Sort an array of strings.
 */
static int
#ifdef __BORLANDC__
_RTLENTRYF
#endif
sort_compare __ARGS((const void *s1, const void *s2));

    static int
#ifdef __BORLANDC__
_RTLENTRYF
#endif
sort_compare(s1, s2)
    const void  *s1;
    const void  *s2;
{
    return STRCMP(*(char **)s1, *(char **)s2);
}

    void
sort_strings(files, count)
    char_u      **files;
    int         count;
{
    qsort((void *)files, (size_t)count, sizeof(char_u *), sort_compare);
}

#if !defined(NO_EXPANDPATH) || defined(PROTO)
/*
 * Compare path "p[]" to "q[]".
 * If "maxlen" >= 0 compare "p[maxlen]" to "q[maxlen]"
 * Return value like strcmp(p, q), but consider path separators.
 */
    int
pathcmp(p, q, maxlen)
    const char *p, *q;
    int maxlen;
{
    int         i;
    const char  *s = NULL;

    for (i = 0; maxlen < 0 || i < maxlen; ++i)
    {
        /* End of "p": check if "q" also ends or just has a slash. */
        if (p[i] == NUL)
        {
            if (q[i] == NUL)  /* full match */
                return 0;
            s = q;
            break;
        }

        /* End of "q": check if "p" just has a slash. */
        if (q[i] == NUL)
        {
            s = p;
            break;
        }

        if (
#ifdef CASE_INSENSITIVE_FILENAME
                TOUPPER_LOC(p[i]) != TOUPPER_LOC(q[i])
#else
                p[i] != q[i]
#endif
#ifdef BACKSLASH_IN_FILENAME
                /* consider '/' and '\\' to be equal */
                && !((p[i] == '/' && q[i] == '\\')
                    || (p[i] == '\\' && q[i] == '/'))
#endif
                )
        {
            if (vim_ispathsep(p[i]))
                return -1;
            if (vim_ispathsep(q[i]))
                return 1;
            return ((char_u *)p)[i] - ((char_u *)q)[i];     /* no match */
        }
    }
    if (s == NULL)      /* "i" ran into "maxlen" */
        return 0;

    /* ignore a trailing slash, but not "//" or ":/" */
    if (s[i + 1] == NUL
            && i > 0
            && !after_pathsep((char_u *)s, (char_u *)s + i)
#ifdef BACKSLASH_IN_FILENAME
            && (s[i] == '/' || s[i] == '\\')
#else
            && s[i] == '/'
#endif
       )
        return 0;   /* match with trailing slash */
    if (s == q)
        return -1;          /* no match */
    return 1;
}
#endif

/*
 * The putenv() implementation below comes from the "screen" program.
 * Included with permission from Juergen Weigert.
 * See pty.c for the copyright notice.
 */

/*
 *  putenv  --  put value into environment
 *
 *  Usage:  i = putenv (string)
 *    int i;
 *    char  *string;
 *
 *  where string is of the form <name>=<value>.
 *  Putenv returns 0 normally, -1 on error (not enough core for malloc).
 *
 *  Putenv may need to add a new name into the environment, or to
 *  associate a value longer than the current value with a particular
 *  name.  So, to make life simpler, putenv() copies your entire
 *  environment into the heap (i.e. malloc()) from the stack
 *  (i.e. where it resides when your process is initiated) the first
 *  time you call it.
 *
 *  (history removed, not very interesting.  See the "screen" sources.)
 */

#if !defined(HAVE_SETENV) && !defined(HAVE_PUTENV)

#define EXTRASIZE 5             /* increment to add to env. size */

static int  envsize = -1;       /* current size of environment */
#ifndef MACOS_CLASSIC
extern
#endif
       char **environ;          /* the global which is your env. */

static int  findenv __ARGS((char *name)); /* look for a name in the env. */
static int  newenv __ARGS((void));      /* copy env. from stack to heap */
static int  moreenv __ARGS((void));     /* incr. size of env. */

    int
putenv(string)
    const char *string;
{
    int     i;
    char    *p;

    if (envsize < 0)
    {                           /* first time putenv called */
        if (newenv() < 0)       /* copy env. to heap */
            return -1;
    }

    i = findenv((char *)string); /* look for name in environment */

    if (i < 0)
    {                           /* name must be added */
        for (i = 0; environ[i]; i++);
        if (i >= (envsize - 1))
        {                       /* need new slot */
            if (moreenv() < 0)
                return -1;
        }
        p = (char *)alloc((unsigned)(strlen(string) + 1));
        if (p == NULL)          /* not enough core */
            return -1;
        environ[i + 1] = 0;     /* new end of env. */
    }
    else
    {                           /* name already in env. */
        p = vim_realloc(environ[i], strlen(string) + 1);
        if (p == NULL)
            return -1;
    }
    sprintf(p, "%s", string);   /* copy into env. */
    environ[i] = p;

    return 0;
}

    static int
findenv(name)
    char *name;
{
    char    *namechar, *envchar;
    int     i, found;

    found = 0;
    for (i = 0; environ[i] && !found; i++)
    {
        envchar = environ[i];
        namechar = name;
        while (*namechar && *namechar != '=' && (*namechar == *envchar))
        {
            namechar++;
            envchar++;
        }
        found = ((*namechar == '\0' || *namechar == '=') && *envchar == '=');
    }
    return found ? i - 1 : -1;
}

    static int
newenv()
{
    char    **env, *elem;
    int     i, esize;

#ifdef MACOS
    /* for Mac a new, empty environment is created */
    i = 0;
#else
    for (i = 0; environ[i]; i++)
        ;
#endif
    esize = i + EXTRASIZE + 1;
    env = (char **)alloc((unsigned)(esize * sizeof (elem)));
    if (env == NULL)
        return -1;

#ifndef MACOS
    for (i = 0; environ[i]; i++)
    {
        elem = (char *)alloc((unsigned)(strlen(environ[i]) + 1));
        if (elem == NULL)
            return -1;
        env[i] = elem;
        strcpy(elem, environ[i]);
    }
#endif

    env[i] = 0;
    environ = env;
    envsize = esize;
    return 0;
}

    static int
moreenv()
{
    int     esize;
    char    **env;

    esize = envsize + EXTRASIZE;
    env = (char **)vim_realloc((char *)environ, esize * sizeof (*env));
    if (env == 0)
        return -1;
    environ = env;
    envsize = esize;
    return 0;
}

# ifdef USE_VIMPTY_GETENV
    char_u *
vimpty_getenv(string)
    const char_u *string;
{
    int i;
    char_u *p;

    if (envsize < 0)
        return NULL;

    i = findenv((char *)string);

    if (i < 0)
        return NULL;

    p = vim_strchr((char_u *)environ[i], '=');
    return (p + 1);
}
# endif

#endif /* !defined(HAVE_SETENV) && !defined(HAVE_PUTENV) */

#if defined(FEAT_EVAL) || defined(FEAT_SPELL) || defined(PROTO)
/*
 * Return 0 for not writable, 1 for writable file, 2 for a dir which we have
 * rights to write into.
 */
    int
filewritable(fname)
    char_u      *fname;
{
    int         retval = 0;
#if defined(UNIX) || defined(VMS)
    int         perm = 0;
#endif

#if defined(UNIX) || defined(VMS)
    perm = mch_getperm(fname);
#endif
#ifndef MACOS_CLASSIC /* TODO: get either mch_writable or mch_access */
    if (
# ifdef WIN3264
            mch_writable(fname) &&
# else
# if defined(UNIX) || defined(VMS)
            (perm & 0222) &&
#  endif
# endif
            mch_access((char *)fname, W_OK) == 0
       )
#endif
    {
        ++retval;
        if (mch_isdir(fname))
            ++retval;
    }
    return retval;
}
#endif

/*
 * Print an error message with one or two "%s" and one or two string arguments.
 * This is not in message.c to avoid a warning for prototypes.
 */
    int
emsg3(s, a1, a2)
    char_u *s, *a1, *a2;
{
    if (emsg_not_now())
        return TRUE;            /* no error messages at the moment */
#ifdef HAVE_STDARG_H
    vim_snprintf((char *)IObuff, IOSIZE, (char *)s, a1, a2);
#else
    vim_snprintf((char *)IObuff, IOSIZE, (char *)s, (long_u)a1, (long_u)a2);
#endif
    return emsg(IObuff);
}

/*
 * Print an error message with one "%ld" and one long int argument.
 * This is not in message.c to avoid a warning for prototypes.
 */
    int
emsgn(s, n)
    char_u      *s;
    long        n;
{
    if (emsg_not_now())
        return TRUE;            /* no error messages at the moment */
    vim_snprintf((char *)IObuff, IOSIZE, (char *)s, n);
    return emsg(IObuff);
}