popen.c: some cleanup, use other wait_child() from now on

[s-mailx.git] / lex.c

/*@ S-nail - a mail user agent derived from Berkeley Mail.
 *@ (Lexical processing of) Commands, and the event mainloop.
 *
 * Copyright (c) 2000-2004 Gunnar Ritter, Freiburg i. Br., Germany.
 * Copyright (c) 2012 - 2013 Steffen "Daode" Nurpmeso <sdaoden@users.sf.net>.
 */
/*
 * Copyright (c) 1980, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef HAVE_AMALGAMATION
# include "nail.h"
#endif

#include <fcntl.h>

struct cmd {
   char const     *name;         /* Name of command */
   int            (*func)(void*); /* Implementor of command */
   enum argtype   argtype;       /* Arglist type (see below) */
   short          msgflag;       /* Required flags of msgs*/
   short          msgmask;       /* Relevant flags of msgs */
#ifdef HAVE_DOCSTRINGS
   int            docid;         /* Translation id of .doc */
   char const     *doc;          /* One line doc for command */
#endif
};
/* Yechh, can't initialize unions */
#define minargs   msgflag        /* Minimum argcount for RAWLIST */
#define maxargs   msgmask        /* Max argcount for RAWLIST */

struct cmd_ghost {
   struct cmd_ghost  *next;
   struct str        cmd;        /* Data follows after .name */
   char              name[VFIELD_SIZE(sizeof(size_t))];
};

static int              *_msgvec;
static int              _reset_on_stop;   /* do a reset() if stopped */
static sighandler_type  _oldpipe;
static struct cmd_ghost *_cmd_ghosts;
/* _cmd_tab[] after fun protos */

/* Update mailname (if name != NULL) and displayname, return wether displayname
 * was large enough to swallow mailname */
static bool_t  _update_mailname(char const *name);
#ifdef HAVE_MBLEN /* TODO unite __narrow_{pre,suf}fix() into one function! */
SINLINE size_t __narrow_prefix(char const *cp, size_t maxl);
SINLINE size_t __narrow_suffix(char const *cp, size_t cpl, size_t maxl);
#endif

/* Isolate the command from the arguments */
static char *  _lex_isolate(char const *comm);

/* Get first-fit, or NULL */
static struct cmd const * _lex(char const *comm);

/* Command ghost handling */
static int     _ghost(void *v);
static int     _unghost(void *v);

/* Print a list of all commands */
static int     _pcmdlist(void *v);
static int     __pcmd_cmp(void const *s1, void const *s2);

static void stop(int s);
static void hangup(int s);

/* List of all commands */
static struct cmd const _cmd_tab[] = {
#include "cmd_tab.h"
};

#ifdef HAVE_MBLEN
SINLINE size_t
__narrow_prefix(char const *cp, size_t maxl)
{
        int err;
        size_t i, ok;

        for (err = ok = i = 0; i < maxl;) {
                int ml = mblen(cp, maxl - i);
                if (ml < 0) { /* XXX _narrow_prefix(): mblen() error; action? */
                        (void)mblen(NULL, 0);
                        err = 1;
                        ml = 1;
                } else {
                        if (! err)
                                ok = i;
                        err = 0;
                        if (ml == 0)
                                break;
                }
                cp += ml;
                i += ml;
        }
        return ok;
}

SINLINE size_t
__narrow_suffix(char const *cp, size_t cpl, size_t maxl)
{
        int err;
        size_t i, ok;

        for (err = ok = i = 0; cpl > maxl || err;) {
                int ml = mblen(cp, cpl);
                if (ml < 0) { /* XXX _narrow_suffix(): mblen() error; action? */
                        (void)mblen(NULL, 0);
                        err = 1;
                        ml = 1;
                } else {
                        if (! err)
                                ok = i;
                        err = 0;
                        if (ml == 0)
                                break;
                }
                cp += ml;
                i += ml;
                cpl -= ml;
        }
        return ok;
}
#endif /* HAVE_MBLEN */

static bool_t
_update_mailname(char const *name)
{
   char tbuf[MAXPATHLEN], *mailp, *dispp;
   size_t i, j;
   bool_t rv;

   /* Don't realpath(3) if it's only an update request */
   if (name != NULL) {
#ifdef HAVE_REALPATH
      enum protocol p = which_protocol(name);
      if (p == PROTO_FILE || p == PROTO_MAILDIR) {
         if (realpath(name, mailname) == NULL) {
            fprintf(stderr, tr(151, "Can't canonicalize `%s'\n"), name);
            rv = FAL0;
            goto jleave;
         }
      } else
#endif
         n_strlcpy(mailname, name, sizeof(mailname));
   }

   mailp = mailname;
   dispp = displayname;

   /* Don't display an absolute path but "+FOLDER" if under *folder* */
   if (getfold(tbuf, sizeof tbuf)) {
      i = strlen(tbuf);
      if (i < sizeof(tbuf) - 1)
         tbuf[i++] = '/';
      if (strncmp(tbuf, mailp, i) == 0) {
         mailp += i;
         *dispp++ = '+';
      }
   }

   /* We want to see the name of the folder .. on the screen */
   i = strlen(mailp);
   if ((rv = (i < sizeof(displayname) - 1)))
      memcpy(dispp, mailp, i + 1);
   else {
      /* Avoid disrupting multibyte sequences (if possible) */
#ifndef HAVE_MBLEN
      j = sizeof(displayname) / 3 - 1;
      i -= sizeof(displayname) - (1/* + */ + 3) - j;
#else
      j = __narrow_prefix(mailp, sizeof(displayname) / 3);
      i = j + __narrow_suffix(mailp + j, i - j,
         sizeof(displayname) - (1/* + */ + 3 + 1) - j);
#endif
      snprintf(dispp, sizeof(displayname), "%.*s...%s",
         (int)j, mailp, mailp + i);
   }
#ifdef HAVE_REALPATH
jleave:
#endif
   return rv;
}

static char *
_lex_isolate(char const *comm)
{
   while (*comm && strchr(" \t0123456789$^.:/-+*'\",;(`", *comm) == NULL)
      ++comm;
   return UNCONST(comm);
}

static struct cmd const *
_lex(char const *comm)
{
   struct cmd const *cp;

   for (cp = _cmd_tab; cp->name != NULL; ++cp)
      if (is_prefix(comm, cp->name))
         goto jleave;
   cp = NULL;
jleave:
   return cp;
}

static int
_ghost(void *v)
{
   char const **argv = (char const **)v;
   struct cmd_ghost *lcg, *cg;
   size_t nl, cl;

   /* Show the list? */
   if (*argv == NULL) {
      printf(tr(144, "Command ghosts are:\n"));
      for (nl = 0, cg = _cmd_ghosts; cg != NULL; cg = cg->next) {
         cl = strlen(cg->name) + 5 + cg->cmd.l + 3;
         if ((nl += cl) >= (size_t)scrnwidth) {
            nl = cl;
            printf("\n");
         }
         printf((cg->next != NULL ? "%s -> <%s>, " : "%s -> <%s>\n"),
            cg->name, cg->cmd.s);
      }
      v = NULL;
      goto jleave;
   }

   /* Request to add new ghost */
   if (argv[1] == NULL || argv[1][0] == '\0' || argv[2] != NULL) {
      fprintf(stderr, tr(159, "Usage: %s\n"),
         tr(425, "Define a <ghost> of <command>, or list all ghosts"));
      v = NULL;
      goto jleave;
   }

   /* Check that we can deal with this one */
   switch (argv[0][0]) {
   case '|':
   case '~':
   case '?':
   case '#':
      /* FALLTHRU */
   case '\0':
      goto jecanon;
   default:
      if (argv[0] == _lex_isolate(argv[0])) {
jecanon:
         fprintf(stderr, tr(151, "Can't canonicalize `%s'\n"), argv[0]);
         v = NULL;
         goto jleave;
      }
      break;
   }

   /* Always recreate */
   for (lcg = NULL, cg = _cmd_ghosts; cg != NULL; lcg = cg, cg = cg->next)
      if (strcmp(cg->name, argv[0]) == 0) {
         if (lcg != NULL)
            lcg->next = cg->next;
         else
            _cmd_ghosts = cg->next;
         free(cg);
         break;
      }

   /* Need a new one */
   nl = strlen(argv[0]) + 1;
   cl = strlen(argv[1]) + 1;
   cg = smalloc(sizeof(*cg) - VFIELD_SIZEOF(struct cmd_ghost, name) + nl + cl);
   cg->next = _cmd_ghosts;
   memcpy(cg->name, argv[0], nl);
   cg->cmd.s = cg->name + nl;
   cg->cmd.l = cl - 1;
   memcpy(cg->cmd.s, argv[1], cl);

   _cmd_ghosts = cg;
jleave:
   return (v == NULL);
}

static int
_unghost(void *v)
{
   int rv = 0;
   char const **argv = v, *cp;
   struct cmd_ghost *lcg, *cg;

   while ((cp = *argv++) != NULL) {
      for (lcg = NULL, cg = _cmd_ghosts; cg != NULL; lcg = cg, cg = cg->next)
         if (strcmp(cg->name, cp) == 0) {
            if (lcg != NULL)
               lcg->next = cg->next;
            else
               _cmd_ghosts = cg->next;
            free(cg);
            goto jouter;
         }
      fprintf(stderr, tr(91, "Unknown command: `%s'\n"), cp);
      rv = 1;
jouter:
      ;
   }
   return rv;
}

static int
__pcmd_cmp(void const *s1, void const *s2)
{
   struct cmd const * const *c1 = s1, * const *c2 = s2;
   return (strcmp((*c1)->name, (*c2)->name));
}

static int
_pcmdlist(void *v)
{
   struct cmd const **cpa, *cp, **cursor;
   size_t i;
   (void)v;

   for (i = 0; _cmd_tab[i].name != NULL; ++i)
      ;
   ++i;
   cpa = ac_alloc(sizeof(cp) * i);

   for (i = 0; (cp = _cmd_tab + i)->name != NULL; ++i)
      cpa[i] = cp;
   cpa[i] = NULL;

   qsort(cpa, i, sizeof(cp), &__pcmd_cmp);

   printf(tr(14, "Commands are:\n"));
   for (i = 0, cursor = cpa; (cp = *cursor++) != NULL;) {
      size_t j;
      if (cp->func == &ccmdnotsupp)
         continue;
      j = strlen(cp->name) + 2;
      if ((i += j) > 72) {
         i = j;
         printf("\n");
      }
      printf((*cursor != NULL ? "%s, " : "%s\n"), cp->name);
   }

   ac_free(cpa);
   return 0;
}

/*
 * Set up editing on the given file name.
 * If the first character of name is %, we are considered to be
 * editing the file, otherwise we are reading our mail which has
 * signficance for mbox and so forth.
 *
 * nmail: Check for new mail in the current folder only.
 */
FL int
setfile(char const *name, int nmail)
{
        FILE *ibuf;
        int i, compressed = 0;
        struct stat stb;
        bool_t isedit;
        char const *who = name[1] ? name + 1 : myname;
        static int shudclob;
        size_t offset;
        int omsgCount = 0;
        struct shortcut *sh;
        struct flock    flp;

        /* Note we don't 'userid(myname) != getuid()', preliminary steps are usually
         * necessary to make a mailbox accessible by a different user, and if that
         * has happened, let's just let the usual file perms decide */
        isedit = (*name != '%' && ((sh = get_shortcut(name)) == NULL ||
                        *sh->sh_long != '%'));
        if ((name = expand(name)) == NULL)
                return (-1);

        switch (which_protocol(name)) {
        case PROTO_FILE:
                break;
        case PROTO_MAILDIR:
                return (maildir_setfile(name, nmail, isedit));
#ifdef HAVE_POP3
        case PROTO_POP3:
                shudclob = 1;
                return (pop3_setfile(name, nmail, isedit));
#endif
#ifdef HAVE_IMAP
        case PROTO_IMAP:
                shudclob = 1;
                if (nmail) {
                        if (mb.mb_type == MB_CACHE)
                                return 1;
                }
                return imap_setfile(name, nmail, isedit);
#endif
        default:
                fprintf(stderr, tr(217, "Cannot handle protocol: %s\n"), name);
                return (-1);
        }

        if ((ibuf = Zopen(name, "r", &compressed)) == NULL) {
                if ((!isedit && errno == ENOENT) || nmail) {
                        if (nmail)
                                goto jnonmail;
                        goto nomail;
                }
                perror(name);
                return(-1);
        }

        if (fstat(fileno(ibuf), &stb) < 0) {
                Fclose(ibuf);
                if (nmail)
                        goto jnonmail;
                perror("fstat");
                return (-1);
        }

        if (S_ISDIR(stb.st_mode)) {
                Fclose(ibuf);
                if (nmail)
                        goto jnonmail;
                errno = EISDIR;
                perror(name);
                return (-1);
        } else if (S_ISREG(stb.st_mode)) {
                /*EMPTY*/
        } else {
                Fclose(ibuf);
                if (nmail)
                        goto jnonmail;
                errno = EINVAL;
                perror(name);
                return (-1);
        }

        /*
         * Looks like all will be well.  We must now relinquish our
         * hold on the current set of stuff.  Must hold signals
         * while we are reading the new file, else we will ruin
         * the message[] data structure.
         */

        hold_sigs(); /* TODO note on this one in quit.c:quit() */
        if (shudclob && !nmail)
                quit();
#ifdef HAVE_SOCKETS
        if (!nmail && mb.mb_sock.s_fd >= 0)
                sclose(&mb.mb_sock);
#endif

        /*
         * Copy the messages into /tmp
         * and set pointers.
         */

        flp.l_type = F_RDLCK;
        flp.l_start = 0;
        flp.l_whence = SEEK_SET;
        if (!nmail) {
                mb.mb_type = MB_FILE;
                mb.mb_perm = (options & OPT_R_FLAG) ? 0 : MB_DELE|MB_EDIT;
                mb.mb_compressed = compressed;
                if (compressed) {
                        if (compressed & 0200)
                                mb.mb_perm = 0;
                } else {
                        if ((i = open(name, O_WRONLY)) < 0)
                                mb.mb_perm = 0;
                        else
                                close(i);
                }
                if (shudclob) {
                        if (mb.mb_itf) {
                                fclose(mb.mb_itf);
                                mb.mb_itf = NULL;
                        }
                        if (mb.mb_otf) {
                                fclose(mb.mb_otf);
                                mb.mb_otf = NULL;
                        }
                }
                shudclob = 1;
                edit = isedit;
                initbox(name);
                offset = 0;
                flp.l_len = 0;
                if (!edit && fcntl(fileno(ibuf), F_SETLKW, &flp) < 0) {
                        perror("Unable to lock mailbox");
                        Fclose(ibuf);
                        return -1;
                }
        } else /* nmail */{
                fseek(mb.mb_otf, 0L, SEEK_END);
                fseek(ibuf, mailsize, SEEK_SET);
                offset = mailsize;
                omsgCount = msgCount;
                flp.l_len = offset;
                if (!edit && fcntl(fileno(ibuf), F_SETLKW, &flp) < 0)
                        goto jnonmail;
        }
        mailsize = fsize(ibuf);
        if (nmail && (size_t)mailsize <= offset) {
                rele_sigs();
                goto jnonmail;
        }
        setptr(ibuf, offset);
        setmsize(msgCount);
        if (nmail && mb.mb_sorted) {
                mb.mb_threaded = 0;
                sort((void *)-1);
        }
        Fclose(ibuf);
        rele_sigs();
        if (!nmail)
                sawcom = FAL0;
        if ((!edit || nmail) && msgCount == 0) {
jnonmail:
                if (!nmail) {
                        if (value("emptystart") == NULL)
nomail:                         fprintf(stderr, tr(88, "No mail for %s\n"),
                                        who);
                }
                return 1;
        }
        if (nmail) {
                newmailinfo(omsgCount);
        }
        return(0);
}

FL int
newmailinfo(int omsgCount)
{
        int     mdot;
        int     i;

        for (i = 0; i < omsgCount; i++)
                message[i].m_flag &= ~MNEWEST;
        if (msgCount > omsgCount) {
                for (i = omsgCount; i < msgCount; i++)
                        message[i].m_flag |= MNEWEST;
                printf(tr(158, "New mail has arrived.\n"));
                if (msgCount - omsgCount == 1)
                        printf(tr(214, "Loaded 1 new message.\n"));
                else
                        printf(tr(215, "Loaded %d new messages.\n"),
                                msgCount - omsgCount);
        } else
                printf(tr(224, "Loaded %d messages.\n"), msgCount);
        callhook(mailname, 1);
        mdot = getmdot(1);
        if (value("header")) {
#ifdef HAVE_IMAP
                if (mb.mb_type == MB_IMAP)
                        imap_getheaders(omsgCount+1, msgCount);
#endif
                time_current_update(&time_current, FAL0);
                while (++omsgCount <= msgCount)
                        if (visible(&message[omsgCount-1]))
                                printhead(omsgCount, stdout, 0);
        }
        return mdot;
}

/*
 * Interpret user commands one by one.  If standard input is not a tty,
 * print no prompt.
 */
FL void
commands(void)
{
        int eofloop = 0, n;
        char *linebuf = NULL, *av, *nv;
        size_t linesize = 0;
#ifdef HAVE_IMAP
        int x;
#endif

        if (!sourcing) {
                if (safe_signal(SIGINT, SIG_IGN) != SIG_IGN)
                        safe_signal(SIGINT, onintr);
                if (safe_signal(SIGHUP, SIG_IGN) != SIG_IGN)
                        safe_signal(SIGHUP, hangup);
                /* TODO We do a lot of redundant signal handling, especially
                 * TODO with the command line editor(s); try to merge this */
                safe_signal(SIGTSTP, stop);
                safe_signal(SIGTTOU, stop);
                safe_signal(SIGTTIN, stop);
        }
        _oldpipe = safe_signal(SIGPIPE, SIG_IGN);
        safe_signal(SIGPIPE, _oldpipe);
        setexit();

        for (;;) {
                interrupts = 0;
                handlerstacktop = NULL;
                /*
                 * Print the prompt, if needed.  Clear out
                 * string space, and flush the output.
                 */
                if (! sourcing && (options & OPT_INTERACTIVE)) {
                        av = (av = value("autoinc")) ? savestr(av) : NULL;
                        nv = (nv = value("newmail")) ? savestr(nv) : NULL;
                        if ((options & OPT_TTYIN) &&
                                        (av != NULL || nv != NULL ||
                                        mb.mb_type == MB_IMAP)) {
                                struct stat st;

                                n = (av && strcmp(av, "noimap") &&
                                                strcmp(av, "nopoll")) |
                                        (nv && strcmp(nv, "noimap") &&
                                                strcmp(nv, "nopoll"));
#ifdef HAVE_IMAP
                                x = !(av || nv);
#endif
                                if ((mb.mb_type == MB_FILE &&
                                                stat(mailname, &st) == 0 &&
                                                st.st_size > mailsize) ||
#ifdef HAVE_IMAP
                                                (mb.mb_type == MB_IMAP &&
                                                imap_newmail(n) > x) ||
#endif
                                                (mb.mb_type == MB_MAILDIR &&
                                                n != 0)) {
                                        int odot = dot - &message[0];
                                        bool_t odid = did_print_dot;

                                        setfile(mailname, 1);
                                        if (mb.mb_type != MB_IMAP) {
                                                dot = &message[odot];
                                                did_print_dot = odid;
                                        }
                                }
                        }
                        _reset_on_stop = 1;
                        exit_status = 0;
                }

                sreset(sourcing);
                if (!sourcing) {
                        /* TODO Note: this buffer may contain a password
                         * TODO We should redefine the code flow which has
                         * TODO to do that */
                        if ((nv = termios_state.ts_linebuf) != NULL) {
                                termios_state.ts_linebuf = NULL;
                                termios_state.ts_linesize = 0;
                                free(nv); /* TODO pool give-back */
                        }
                        /* TODO Due to expand-on-tab of our line editor the
                         * TODO buffer may grow */
                        if (linesize > LINESIZE * 3) {
                                free(linebuf); /* TODO pool! but what? */
                                linebuf = NULL;
                                linesize = 0;
                        }
                }

                /*
                 * Read a line of commands from the current input
                 * and handle end of file specially.
                 */
                n = readline_input(LNED_LF_ESC | LNED_HIST_ADD, NULL,
                        &linebuf, &linesize);
                _reset_on_stop = 0;
                if (n < 0) {
                                /* eof */
                        if (loading)
                                break;
                        if (sourcing) {
                                unstack();
                                continue;
                        }
                        if ((options & OPT_INTERACTIVE) &&
                                        value("ignoreeof") && ++eofloop < 25) {
                                printf(tr(89, "Use `quit' to quit.\n"));
                                continue;
                        }
                        break;
                }

                eofloop = 0;
                inhook = 0;
                if (execute(linebuf, 0, n))
                        break;
                if (exit_status != EXIT_OK && (options & OPT_BATCH_FLAG) &&
                                boption("batch-exit-on-error"))
                        break;
        }

        if (linebuf != NULL)
                free(linebuf);
        if (sourcing)
                sreset(FAL0);
}

/*
 * Execute a single command.
 * Command functions return 0 for success, 1 for error, and -1
 * for abort.  A 1 or -1 aborts a load or source.  A -1 aborts
 * the interactive command loop.
 * Contxt is non-zero if called while composing mail.
 */
FL int
execute(char *linebuf, int contxt, size_t linesize)
{
        char _wordbuf[2], *arglist[MAXARGC], *cp, *word;
        struct cmd_ghost *cg = NULL;
        struct cmd const *com = NULL;
        int muvec[2], c, e = 1;

        /* Command ghosts that refer to shell commands or macro expansion restart */
jrestart:

        /* Strip the white space away from the beginning of the command */
        for (cp = linebuf; whitechar(*cp); ++cp)
                ;
        linesize -= (size_t)(cp - linebuf);

        /* Ignore comments */
        if (*cp == '#')
                goto jleave0;

        /* Handle ! differently to get the correct lexical conventions */
        if (*cp == '!') {
                if (sourcing) {
                        fprintf(stderr, tr(90, "Can't `!' while sourcing\n"));
                        goto jleave;
                }
                shell(++cp);
                goto jleave0;
        }

        /* Isolate the actual command; since it may not necessarily be
         * separated from the arguments (as in `p1') we need to duplicate it to
         * be able to create a NUL terminated version.
         * We must be aware of special one letter commands here */
        arglist[0] = cp;
        switch (*cp) {
        case '|':
        case '~':
        case '?':
                ++cp;
                /* FALLTHRU */
        case '\0':
                break;
        default:
                cp = _lex_isolate(cp);
                break;
        }
        c = (int)(cp - arglist[0]);
        linesize -= c;
        word = (c < (int)sizeof _wordbuf) ? _wordbuf : salloc(c + 1);
        memcpy(word, arglist[0], c);
        word[c] = '\0';

        /* Look up the command; if not found, bitch.
         * Normally, a blank command would map to the first command in the
         * table; while sourcing, however, we ignore blank lines to eliminate
         * confusion; act just the same for ghosts */
        if ((sourcing || cg != NULL) && *word == '\0')
                goto jleave0;

        /* If this is the first evaluation, check command ghosts */
        if (cg == NULL) {
      /* TODO relink list head, so it's sort over time on usage? */
                for (cg = _cmd_ghosts; cg != NULL; cg = cg->next)
                        if (strcmp(word, cg->name) == 0) {
                                if (linesize > 0) {
                                        size_t i = cg->cmd.l;
                                        linebuf = salloc(i + 1 + linesize);
                                        memcpy(linebuf, cg->cmd.s, i);
                                        linebuf[i++] = ' ';
                                        memcpy(linebuf + i, cp, linesize);
                                        linebuf[i += linesize] = '\0';
                                        linesize = i;
                                } else {
                                        linebuf = cg->cmd.s;
                                        linesize = cg->cmd.l;
                                }
                                goto jrestart;
                        }
        }

        if (com == NULL)
                com = _lex(word);
        if (com == NULL || com->func == &ccmdnotsupp) {
                fprintf(stderr, tr(91, "Unknown command: `%s'\n"), word);
                if (com != NULL) {
                        ccmdnotsupp(NULL);
                        com = NULL;
                }
                goto jleave;
        }

        /*
         * See if we should execute the command -- if a conditional
         * we always execute it, otherwise, check the state of cond.
         */
        if ((com->argtype & F) == 0) {
                if ((cond == CRCV && (options & OPT_SENDMODE)) ||
                                (cond == CSEND && ! (options & OPT_SENDMODE)) ||
                                (cond == CTERM && ! (options & OPT_TTYIN)) ||
                                (cond == CNONTERM && (options & OPT_TTYIN)))
                        goto jleave0;
        }

        /*
         * Process the arguments to the command, depending
         * on the type he expects.  Default to an error.
         * If we are sourcing an interactive command, it's
         * an error.
         */
        if ((options & OPT_SENDMODE) && (com->argtype & M) == 0) {
                fprintf(stderr, tr(92,
                        "May not execute `%s' while sending\n"),
                        com->name);
                goto jleave;
        }
        if (sourcing && com->argtype & I) {
                fprintf(stderr, tr(93,
                        "May not execute `%s' while sourcing\n"),
                        com->name);
                goto jleave;
        }
        if ((mb.mb_perm & MB_DELE) == 0 && com->argtype & W) {
                fprintf(stderr, tr(94, "May not execute `%s' -- "
                        "message file is read only\n"),
                        com->name);
                goto jleave;
        }
        if (contxt && com->argtype & R) {
                fprintf(stderr, tr(95,
                        "Cannot recursively invoke `%s'\n"), com->name);
                goto jleave;
        }
        if (mb.mb_type == MB_VOID && com->argtype & A) {
                fprintf(stderr, tr(257,
                        "Cannot execute `%s' without active mailbox\n"),
                        com->name);
                goto jleave;
        }

        switch (com->argtype & ~(F|P|I|M|T|W|R|A)) {
        case MSGLIST:
                /* Message list defaulting to nearest forward legal message */
                if (_msgvec == 0)
                        goto je96;
                if ((c = getmsglist(cp, _msgvec, com->msgflag)) < 0)
                        break;
                if (c == 0) {
                        *_msgvec = first(com->msgflag, com->msgmask);
                        if (*_msgvec != 0)
                                _msgvec[1] = 0;
                }
                if (*_msgvec == 0) {
                        if (! inhook)
                                printf(tr(97, "No applicable messages\n"));
                        break;
                }
                e = (*com->func)(_msgvec);
                break;

        case NDMLIST:
                /* Message list with no defaults, but no error if none exist */
                if (_msgvec == 0) {
je96:
                        fprintf(stderr, tr(96,
                                "Illegal use of `message list'\n"));
                        break;
                }
                if ((c = getmsglist(cp, _msgvec, com->msgflag)) < 0)
                        break;
                e = (*com->func)(_msgvec);
                break;

        case STRLIST:
                /* Just the straight string, with leading blanks removed */
                while (whitechar(*cp))
                        cp++;
                e = (*com->func)(cp);
                break;

        case RAWLIST:
        case ECHOLIST:
                /* A vector of strings, in shell style */
                if ((c = getrawlist(cp, linesize, arglist,
                                sizeof arglist / sizeof *arglist,
                                (com->argtype&~(F|P|I|M|T|W|R|A)) == ECHOLIST)
                                ) < 0)
                        break;
                if (c < com->minargs) {
                        fprintf(stderr, tr(99,
                                "`%s' requires at least %d arg(s)\n"),
                                com->name, com->minargs);
                        break;
                }
                if (c > com->maxargs) {
                        fprintf(stderr, tr(100,
                                "`%s' takes no more than %d arg(s)\n"),
                                com->name, com->maxargs);
                        break;
                }
                e = (*com->func)(arglist);
                break;

        case NOLIST:
                /* Just the constant zero, for exiting, eg. */
                e = (*com->func)(0);
                break;

        default:
                panic(tr(101, "Unknown argument type"));
        }

jleave:
        /* Exit the current source file on error */
        if ((exec_last_comm_error = (e != 0))) {
                if (e < 0)
                        return 1;
                if (loading)
                        return 1;
                if (sourcing)
                        unstack();
                return 0;
        }
        if (com == (struct cmd*)NULL )
                return 0;
        if (boption("autoprint") && com->argtype & P)
                if (visible(dot)) {
                        muvec[0] = dot - &message[0] + 1;
                        muvec[1] = 0;
                        type(muvec);
                }
        if (! sourcing && ! inhook && (com->argtype & T) == 0)
                sawcom = TRU1;
jleave0:
        return 0;
}

/*
 * Set the size of the message vector used to construct argument
 * lists to message list functions.
 */
FL void
setmsize(int sz)
{

        if (_msgvec != 0)
                free(_msgvec);
        _msgvec = (int*)scalloc(sz + 1, sizeof *_msgvec);
}

/*
 * The following gets called on receipt of an interrupt.  This is
 * to abort printout of a command, mainly.
 * Dispatching here when command() is inactive crashes rcv.
 * Close all open files except 0, 1, 2, and the temporary.
 * Also, unstack all source files.
 */

static int      inithdr;                /* am printing startup headers */

/*ARGSUSED*/
FL void
onintr(int s)
{
        if (handlerstacktop != NULL) {
                handlerstacktop(s);
                return;
        }
        safe_signal(SIGINT, onintr);
        noreset = 0;
        if (!inithdr)
                sawcom = TRU1;
        inithdr = 0;
        while (sourcing)
                unstack();

        termios_state_reset();
        close_all_files();

        if (image >= 0) {
                close(image);
                image = -1;
        }
        if (interrupts != 1)
                fprintf(stderr, tr(102, "Interrupt\n"));
        safe_signal(SIGPIPE, _oldpipe);
        reset(0);
}

/*
 * When we wake up after ^Z, reprint the prompt.
 */
static void
stop(int s)
{
        sighandler_type old_action = safe_signal(s, SIG_DFL);
        sigset_t nset;

        sigemptyset(&nset);
        sigaddset(&nset, s);
        sigprocmask(SIG_UNBLOCK, &nset, (sigset_t *)NULL);
        kill(0, s);
        sigprocmask(SIG_BLOCK, &nset, (sigset_t *)NULL);
        safe_signal(s, old_action);
        if (_reset_on_stop) {
                _reset_on_stop = 0;
                reset(0);
        }
}

/*
 * Branch here on hangup signal and simulate "exit".
 */
/*ARGSUSED*/
static void
hangup(int s)
{
        (void)s;
        /* nothing to do? */
        exit(1);
}

/*
 * Announce the presence of the current Mail version,
 * give the message count, and print a header listing.
 */
FL void
announce(int printheaders)
{
        int vec[2], mdot;

        mdot = newfileinfo();
        vec[0] = mdot;
        vec[1] = 0;
        dot = &message[mdot - 1];
        if (printheaders && msgCount > 0 && value("header") != NULL) {
                inithdr++;
                headers(vec);
                inithdr = 0;
        }
}

/*
 * Announce information about the file we are editing.
 * Return a likely place to set dot.
 */
FL int
newfileinfo(void)
{
        struct message *mp;
        int u, n, mdot, d, s, hidden, moved;

        if (mb.mb_type == MB_VOID)
                return 1;
        mdot = getmdot(0);
        s = d = hidden = moved =0;
        for (mp = &message[0], n = 0, u = 0; mp < &message[msgCount]; mp++) {
                if (mp->m_flag & MNEW)
                        n++;
                if ((mp->m_flag & MREAD) == 0)
                        u++;
                if ((mp->m_flag & (MDELETED|MSAVED)) == (MDELETED|MSAVED))
                        moved++;
                if ((mp->m_flag & (MDELETED|MSAVED)) == MDELETED)
                        d++;
                if ((mp->m_flag & (MDELETED|MSAVED)) == MSAVED)
                        s++;
                if (mp->m_flag & MHIDDEN)
                        hidden++;
        }

        /* If displayname gets truncated the user effectively has no option to see
         * the full pathname of the mailbox, so print it at least for '? fi' */
        printf(tr(103, "\"%s\": "),
                (_update_mailname(NULL) ? displayname : mailname));
        if (msgCount == 1)
                printf(tr(104, "1 message"));
        else
                printf(tr(105, "%d messages"), msgCount);
        if (n > 0)
                printf(tr(106, " %d new"), n);
        if (u-n > 0)
                printf(tr(107, " %d unread"), u);
        if (d > 0)
                printf(tr(108, " %d deleted"), d);
        if (s > 0)
                printf(tr(109, " %d saved"), s);
        if (moved > 0)
                printf(tr(136, " %d moved"), moved);
        if (hidden > 0)
                printf(tr(139, " %d hidden"), hidden);
        if (mb.mb_type == MB_CACHE)
                printf(" [Disconnected]");
        else if (mb.mb_perm == 0)
                printf(tr(110, " [Read only]"));
        printf("\n");
        return(mdot);
}

FL int
getmdot(int nmail)
{
        struct message  *mp;
        char    *cp;
        int     mdot;
        enum mflag      avoid = MHIDDEN|MDELETED;

        if (!nmail) {
                if (value("autothread"))
                        thread(NULL);
                else if ((cp = value("autosort")) != NULL) {
                        free(mb.mb_sorted);
                        mb.mb_sorted = sstrdup(cp);
                        sort(NULL);
                }
        }
        if (mb.mb_type == MB_VOID)
                return 1;
        if (nmail)
                for (mp = &message[0]; mp < &message[msgCount]; mp++)
                        if ((mp->m_flag & (MNEWEST|avoid)) == MNEWEST)
                                break;
        if (!nmail || mp >= &message[msgCount]) {
                for (mp = mb.mb_threaded ? threadroot : &message[0];
                                mb.mb_threaded ?
                                        mp != NULL : mp < &message[msgCount];
                                mb.mb_threaded ?
                                        mp = next_in_thread(mp) : mp++)
                        if ((mp->m_flag & (MNEW|avoid)) == MNEW)
                                break;
        }
        if (mb.mb_threaded ? mp == NULL : mp >= &message[msgCount])
                for (mp = mb.mb_threaded ? threadroot : &message[0];
                                mb.mb_threaded ? mp != NULL:
                                        mp < &message[msgCount];
                                mb.mb_threaded ? mp = next_in_thread(mp) : mp++)
                        if (mp->m_flag & MFLAGGED)
                                break;
        if (mb.mb_threaded ? mp == NULL : mp >= &message[msgCount])
                for (mp = mb.mb_threaded ? threadroot : &message[0];
                                mb.mb_threaded ? mp != NULL:
                                        mp < &message[msgCount];
                                mb.mb_threaded ? mp = next_in_thread(mp) : mp++)
                        if ((mp->m_flag & (MREAD|avoid)) == 0)
                                break;
        if (mb.mb_threaded ? mp != NULL : mp < &message[msgCount])
                mdot = mp - &message[0] + 1;
        else if (value("showlast")) {
                if (mb.mb_threaded) {
                        for (mp = this_in_thread(threadroot, -1); mp;
                                        mp = prev_in_thread(mp))
                                if ((mp->m_flag & avoid) == 0)
                                        break;
                        mdot = mp ? mp - &message[0] + 1 : msgCount;
                } else {
                        for (mp = &message[msgCount-1]; mp >= &message[0]; mp--)
                                if ((mp->m_flag & avoid) == 0)
                                        break;
                        mdot = mp >= &message[0] ? mp-&message[0]+1 : msgCount;
                }
        } else if (mb.mb_threaded) {
                for (mp = threadroot; mp; mp = next_in_thread(mp))
                        if ((mp->m_flag & avoid) == 0)
                                break;
                mdot = mp ? mp - &message[0] + 1 : 1;
        } else {
                for (mp = &message[0]; mp < &message[msgCount]; mp++)
                        if ((mp->m_flag & avoid) == 0)
                                break;
                mdot = mp < &message[msgCount] ? mp-&message[0]+1 : 1;
        }
        return mdot;
}

/*
 * Print the current version number.
 */

/*ARGSUSED*/
FL int
pversion(void *v)
{
   (void)v;
   printf(tr(111, "Version %s\n"), version);
   return 0;
}

FL void
initbox(const char *name)
{
        char *tempMesg;
        int dummy;

        if (mb.mb_type != MB_VOID)
                (void)n_strlcpy(prevfile, mailname, MAXPATHLEN);
        _update_mailname(name != mailname ? name : NULL);
        if ((mb.mb_otf = Ftemp(&tempMesg, "tmpbox", "w", 0600, 0)) == NULL) {
                perror(tr(87, "temporary mail message file"));
                exit(1);
        }
        (void)fcntl(fileno(mb.mb_otf), F_SETFD, FD_CLOEXEC);
        if ((mb.mb_itf = safe_fopen(tempMesg, "r", &dummy)) == NULL) {
                perror(tr(87, "temporary mail message file"));
                exit(1);
        }
        (void)fcntl(fileno(mb.mb_itf), F_SETFD, FD_CLOEXEC);
        rm(tempMesg);
        Ftfree(&tempMesg);
        msgCount = 0;
        if (message) {
                free(message);
                message = NULL;
                msgspace = 0;
        }
        mb.mb_threaded = 0;
        if (mb.mb_sorted != NULL) {
                free(mb.mb_sorted);
                mb.mb_sorted = NULL;
        }
#ifdef HAVE_IMAP
        mb.mb_flags = MB_NOFLAGS;
#endif
        prevdot = NULL;
        dot = NULL;
        did_print_dot = FAL0;
}

#ifdef HAVE_DOCSTRINGS
FL bool_t
print_comm_docstr(char const *comm)
{
   bool_t rv = FAL0;
   struct cmd_ghost *cg;
   struct cmd const *cp;

   /* Ghosts take precedence */
   for (cg = _cmd_ghosts; cg != NULL; cg = cg->next)
      if (strcmp(comm, cg->name) == 0) {
         printf("%s -> <%s>\n", comm, cg->cmd.s);
         rv = TRU1;
         goto jleave;
      }

   for (cp = _cmd_tab; cp->name != NULL; ++cp) {
      if (cp->func == &ccmdnotsupp)
         continue;
      if (strcmp(comm, cp->name) == 0)
         printf("%s: %s\n", comm, tr(cp->docid, cp->doc));
      else if (is_prefix(comm, cp->name))
         printf("%s (%s): %s\n", comm, cp->name, tr(cp->docid, cp->doc));
      else
         continue;
      rv = TRU1;
      break;
   }
jleave:
   return rv;
}
#endif

/* vim:set fenc=utf-8:s-it-mode (TODO only partial true) */