intr: Allow drivers to register high frequency interrupt.

[dragonfly.git] / games / larn / io.c

/* io.c                  Larn is copyrighted 1986 by Noah Morgan.
 * $FreeBSD: src/games/larn/io.c,v 1.7 1999/11/16 02:57:22 billf Exp $
 *
 *      Below are the functions in this file:
 *
 *      setupvt100()    Subroutine to set up terminal in correct mode for game
 *      clearvt100()    Subroutine to clean up terminal when the game is over
 *      getchr()        Routine to read in one character from the terminal
 *      scbr()          Function to set cbreak -echo for the terminal
 *      sncbr()         Function to set -cbreak echo for the terminal
 *      newgame()       Subroutine to save the initial time and seed rnd()
 *
 *      FILE OUTPUT ROUTINES
 *
 *      lprintf(format, args...)        printf to the output buffer
 *      lprint(integer)                 send binary integer to output buffer
 *      lwrite(buf,len)                 write a buffer to the output buffer
 *      lprcat(str)                     sent string to output buffer
 *
 *      FILE OUTPUT MACROS (in header.h)
 *
 *      lprc(character)                 put the character into the output buffer
 *
 *      FILE INPUT ROUTINES
 *
 *      long lgetc()                    read one character from input buffer
 *      long lrint_x()                  read one integer from input buffer
 *      lrfill(address,number)          put input bytes into a buffer
 *      char *lgetw()                   get a whitespace ended word from input
 *      char *lgetl()                   get a \n or EOF ended line from input
 *
 *      FILE OPEN / CLOSE ROUTINES
 *
 *      lcreat(filename)                create a new file for write
 *      lopen(filename)                 open a file for read
 *      lappend(filename)               open for append to an existing file
 *      lrclose()                       close the input file
 *      lwclose()                       close output file
 *      lflush()                        flush the output buffer
 *
 *      Other Routines
 *
 *      cursor(x,y)                     position cursor at [x,y]
 *      cursors()                       position cursor at [1,24] (saves memory)
 *      cl_line(x,y)                    Clear line at [1,y] and leave cursor at [x,y]
 *      cl_up(x,y)                      Clear screen from [x,1] to current line.
 *      cl_dn(x,y)                      Clear screen from [1,y] to end of display.
 *      standout(str)                   Print the string in standout mode.
 *      set_score_output()              Called when output should be literally printed.
 *      putchr(ch)                      Print one character in decoded output buffer.
 *      flush_buf()                     Flush buffer with decoded output.
 *      init_term()                     Terminal initialization -- setup termcap info
 *      char *tmcapcnv(sd,ss)           Routine to convert VT100 \33's to termcap format
 *      beep()          Routine to emit a beep if enabled (see no-beep in .larnopts)
 *
 * Note: ** entries are available only in termcap mode.
 */

#include <stdarg.h>
#include <termios.h>
#include "header.h"

static int rawflg = 0;
static char saveeof, saveeol;

#define LINBUFSIZE 128          /* size of the lgetw() and lgetl() buffer */
int io_outfd;                                   /* output file numbers */
int io_infd;                                    /* input file numbers */
static struct termios ttx;                      /* storage for the tty modes */
static int ipoint=MAXIBUF, iepoint=MAXIBUF;     /* input buffering pointers */
static char lgetwbuf[LINBUFSIZE];               /* get line (word) buffer */

#ifndef VT100
static int putchr(int);
static void flush_buf(void);
#endif

/*
 *      setupvt100()    Subroutine to set up terminal in correct mode for game
 *
 *      Attributes off, clear screen, set scrolling region, set tty mode
 */
void
setupvt100(void)
{
        clear();
        setscroll();
        scbr();
}

/*
 *      clearvt100()    Subroutine to clean up terminal when the game is over
 *
 *      Attributes off, clear screen, unset scrolling region, restore tty mode
 */
void
clearvt100(void)
{
        resetscroll();
        clear();
        sncbr();
}

/*
 *      getchr()        Routine to read in one character from the terminal
 */
char
getchr(void)
{
        char byt;
#ifdef EXTRA
        c[BYTESIN]++;
#endif
        lflush();               /* be sure output buffer is flushed */
        read(0, &byt, 1);       /* get byte from terminal */
        return (byt);
}

/*
 *      scbr()          Function to set cbreak -echo for the terminal
 *
 *      like: system("stty cbreak -echo")
 */
void
scbr(void)
{
        tcgetattr(0, &ttx);
        /* doraw */
        if (!rawflg) {
                ++rawflg;
                saveeof = ttx.c_cc[VMIN];
                saveeol = ttx.c_cc[VTIME];
        }
        ttx.c_cc[VMIN] = 1;
        ttx.c_cc[VTIME] = 1;
        ttx.c_lflag &= ~(ICANON | ECHO | ECHOE | ECHOK | ECHONL);
        tcsetattr(0, TCSANOW, &ttx);
}

/*
 *      sncbr()         Function to set -cbreak echo for the terminal
 *
 *      like: system("stty -cbreak echo")
 */
void
sncbr(void)
{
        tcgetattr(0, &ttx);
        /* unraw */
        ttx.c_cc[VMIN] = saveeof;
        ttx.c_cc[VTIME] = saveeol;
        ttx.c_lflag |= ICANON | ECHO | ECHOE | ECHOK | ECHONL;
        tcsetattr(0, TCSANOW, &ttx);
}

/*
 *      newgame()       Subroutine to save the initial time and seed rnd()
 */
void
newgame(void)
{
        long *p, *pe;
        for (p = c, pe = c + 100; p < pe; *p++ = 0)
                ;
        time(&initialtime);
        srandomdev();
        lcreat(NULL);   /* open buffering for output to terminal */
}

/*
 *      lprintf(format, args...)                printf to the output buffer
 *              char *format;
 *              ??? args...
 *
 *      Enter with the format string in "format", as per printf() usage
 *              and any needed arguments following it
 *      Note: lprintf() only supports %s, %c and %d, with width modifier and left
 *              or right justification.
 *      No correct checking for output buffer overflow is done, but flushes
 *              are done beforehand if needed.
 *      Returns nothing of value.
 */
void
lprintf(const char *fmt, ...)
{
        va_list ap;                     /* pointer for variable argument list */
        char   *outb, *tmpb;
        long    wide, left, cont, n;    /* data for lprintf */
        char    db[12];                 /* %d buffer in lprintf */

        va_start(ap, fmt);              /* initialize the var args pointer */
        if (lpnt >= lpend)
                lflush();
        outb = lpnt;
        for (;;) {
                while (*fmt != '%')
                        if (*fmt)
                                *outb++ = *fmt++;
                        else {
                                lpnt = outb;
                                return;
                        }
                wide = 0;
                left = 1;
                cont = 1;
                while (cont)
                        switch (*(++fmt)) {
                        case 'd':
                                n = va_arg(ap, long);
                                if (n < 0) {
                                        n = -n;
                                        *outb++ = '-';
                                        if (wide)
                                                --wide;
                                }
                                tmpb = db + 11;
                                *tmpb = (char)(n % 10 + '0');
                                while (n > 9)
                                        *(--tmpb) = (char)((n /= 10) % 10 + '0');
                                if (wide == 0)
                                        while (tmpb < db + 12)
                                                *outb++ = *tmpb++;
                                else {
                                        wide -= db - tmpb + 12;
                                        if (left)
                                                while (wide-- > 0)
                                                        *outb++ = ' ';
                                        while (tmpb < db + 12)
                                                *outb++ = *tmpb++;
                                        if (left == 0)
                                                while (wide-- > 0)
                                                        *outb++ = ' ';
                                }
                                cont = 0;
                                break;

                        case 's':
                                tmpb = va_arg(ap, char *);
                                if (wide == 0) {
                                        while ((*outb++ = *tmpb++))
                                                ;
                                        --outb;
                                } else {
                                        n = wide - strlen(tmpb);
                                        if (left)
                                                while (n-- > 0)
                                                        *outb++ = ' ';
                                        while ((*outb++ = *tmpb++))
                                                ;
                                        --outb;
                                        if (left == 0)
                                                while (n-- > 0)
                                                        *outb++ = ' ';
                                }
                                cont = 0;
                                break;

                        case 'c':
                                *outb++ = va_arg(ap, int);
                                cont = 0;
                                break;

                        case '0':
                        case '1':
                        case '2':
                        case '3':
                        case '4':
                        case '5':
                        case '6':
                        case '7':
                        case '8':
                        case '9':
                                wide = 10 * wide + *fmt - '0';
                                break;

                        case '-':
                                left = 0;
                                break;

                        default:
                                *outb++ = *fmt;
                                cont = 0;
                                break;
                        }
                fmt++;
        }
        va_end(ap);
}

/*
 *      lprint(long-integer)    send binary integer to output buffer
 *              long integer;
 *
 *              +---------+---------+---------+---------+
 *              |   high  |         |         |   low   |
 *              |  order  |         |         |  order  |
 *              |   byte  |         |         |   byte  |
 *              +---------+---------+---------+---------+
 *              31  ---  24 23 --- 16 15 ---  8 7  ---   0
 *
 *      The save order is low order first, to high order (4 bytes total)
 *      and is written to be system independent.
 *      No checking for output buffer overflow is done, but flushes if needed!
 *      Returns nothing of value.
 */
void
lprint(long x)
{
        if (lpnt >= lpend)
                lflush();
        *lpnt++ = 255 & x;
        *lpnt++ = 255 & (x >> 8);
        *lpnt++ = 255 & (x >> 16);
        *lpnt++ = 255 & (x >> 24);
}

/*
 *      lwrite(buf,len)         write a buffer to the output buffer
 *              char *buf;
 *              int len;
 *
 *      Enter with the address and number of bytes to write out
 *      Returns nothing of value
 */
void
lwrite(char *buf, int len)
{
        char *str;
        int   num2;

        if (len > 399) {        /* don't copy data if can just write it */
#ifdef EXTRA
                c[BYTESOUT] += len;
#endif

#ifndef VT100
                for (str = buf; len > 0; --len)
                        lprc(*str++);
#else /* VT100 */
                lflush();
                write(io_outfd, buf, len);
#endif /* VT100 */
        } else
                while (len) {
                        if (lpnt >= lpend)      /* if buffer is full flush it */
                                lflush();
                        num2 = lpbuf + BUFBIG - lpnt;   /* # bytes left in output buffer */
                        if (num2 > len)
                                num2 = len;
                        str = lpnt;
                        len -= num2;
                        while (num2--)          /* copy in the bytes */
                                *str++ = *buf++;
                        lpnt = str;
                }
}

/*
 *      long lgetc()    Read one character from input buffer
 *
 *  Returns 0 if EOF, otherwise the character
 */
long
lgetc(void)
{
        int i;
        if (ipoint != iepoint)
                return (inbuffer[ipoint++]);
        if (iepoint != MAXIBUF)
                return (0);
        if ((i = read(io_infd, inbuffer, MAXIBUF)) <= 0) {
                if (i != 0)
                        write(1, "error reading from input file\n", 30);
                iepoint = ipoint = 0;
                return (0);
        }
        ipoint = 1;
        iepoint = i;
        return (*inbuffer);
}

/*
 *      long lrint_x()  Read one integer from input buffer
 *
 *              +---------+---------+---------+---------+
 *              |   high  |         |         |   low   |
 *              |  order  |         |         |  order  |
 *              |   byte  |         |         |   byte  |
 *              +---------+---------+---------+---------+
 *             31  ---  24 23 --- 16 15 ---  8 7  ---   0
 *
 *      The save order is low order first, to high order (4 bytes total)
 *      Returns the int read
 */
long
lrint_x(void)
{
        unsigned long i;
        i = 255 & lgetc();
        i |= (255 & lgetc()) << 8;
        i |= (255 & lgetc()) << 16;
        i |= (255 & lgetc()) << 24;
        return (i);
}

/*
 *      lrfill(address,number)  put input bytes into a buffer
 *              char *address;
 *              int number;
 *
 *      Reads "number" bytes into the buffer pointed to by "address".
 *      Returns nothing of value
 */
void
lrfill(char *adr, int num)
{
        char *pnt;
        int   num2;
        while (num) {
                if (iepoint == ipoint) {
                        if (num > 5) {  /* fast way */
                                if (read(io_infd, adr, num) != num)
                                        write(2, "error reading from input file\n", 30);
                                num = 0;
                        } else {
                                *adr++ = lgetc();
                                --num;
                        }
                } else {
                        num2 = iepoint - ipoint;        /* # of bytes left in the buffer */
                        if (num2 > num)
                                num2 = num;
                        pnt = inbuffer + ipoint;
                        num -= num2;
                        ipoint += num2;
                        while (num2--)
                                *adr++ = *pnt++;
                }
        }
}

/*
 *      char *lgetw()   Get a whitespace ended word from input
 *
 *      Returns pointer to a buffer that contains word.  If EOF, returns a NULL
 */
char *
lgetw(void)
{
        char *lgp, cc;
        int   n = LINBUFSIZE, quote = 0;
        lgp = lgetwbuf;
        do
                cc = lgetc();
        while ((cc <= 32) && (cc > '\0'));      /* eat whitespace */
        for (;; --n, cc = lgetc()) {
                if ((cc == '\0') && (lgp == lgetwbuf))  /* EOF */
                        return (NULL);
                if ((n <= 1) || ((cc <= 32) && (quote == 0))) {
                        *lgp = '\0';
                        return (lgetwbuf);
                }
                if (cc != '"')
                        *lgp++ = cc;
                else
                        quote ^= 1;
        }
}

/*
 *      char *lgetl()   Function to read in a line ended by newline or EOF
 *
 *      Returns pointer to a buffer that contains the line.  If EOF, returns NULL
 */
char *
lgetl(void)
{
        int   i = LINBUFSIZE, ch;
        char *str = lgetwbuf;
        for (;; --i) {
                if ((*str++ = ch = lgetc()) == '\0') {
                        if (str == lgetwbuf + 1)        /* EOF */
                                return (NULL);
ot:
                        *str = 0;
                        return (lgetwbuf);      /* line ended by EOF */
                }
                if ((ch == '\n') || (i <= 1))   /* line ended by \n */
                        goto ot;
        }
}

/*
 *      lcreat(filename)        Create a new file for write
 *              char *filename;
 *
 *      lcreat(NULL); means to the terminal
 *      Returns -1 if error, otherwise the file descriptor opened.
 */
int
lcreat(char *str)
{
        lpnt = lpbuf;
        lpend = lpbuf + BUFBIG;
        if (str == NULL)
                return (io_outfd = 1);
        if ((io_outfd = creat(str, 0644)) < 0) {
                io_outfd = 1;
                lprintf("error creating file <%s>\n", str);
                lflush();
                return (-1);
        }
        return (io_outfd);
}

/*
 *      lopen(filename)         Open a file for read
 *              char *filename;
 *
 *      lopen(0) means from the terminal
 *      Returns -1 if error, otherwise the file descriptor opened.
 */
int
lopen(char *str)
{
        ipoint = iepoint = MAXIBUF;
        if (str == NULL)
                return (io_infd = 0);
        if ((io_infd = open(str, O_RDONLY)) < 0) {
                lwclose();
                io_outfd = 1;
                lpnt = lpbuf;
                return (-1);
        }
        return (io_infd);
}

/*
 *      lappend(filename)       Open for append to an existing file
 *              char *filename;
 *
 *      lappend(0) means to the terminal
 *      Returns -1 if error, otherwise the file descriptor opened.
 */
int
lappend(char *str)
{
        lpnt = lpbuf;
        lpend = lpbuf + BUFBIG;
        if (str == NULL)
                return (io_outfd = 1);
        if ((io_outfd = open(str, O_RDWR)) < 0) {
                io_outfd = 1;
                return (-1);
        }
        lseek(io_outfd, 0, SEEK_END);   /* seek to end of file */
        return (io_outfd);
}

/*
 *      lrclose()       close the input file
 *
 *      Returns nothing of value.
 */
void
lrclose(void)
{
        if (io_infd > 0)
                close(io_infd);
}

/*
 *      lwclose()       close output file flushing if needed
 *
 *      Returns nothing of value.
 */
void
lwclose(void)
{
        lflush();
        if (io_outfd > 2)
                close(io_outfd);
}

/*
 *      lprcat(string)  append a string to the output buffer
 *                          avoids calls to lprintf (time consuming)
 */
void
lprcat(const char *str)
{
        char *str2;
        if (lpnt >= lpend)
                lflush();
        str2 = lpnt;
        while ((*str2++ = *str++) != '\0')
                continue;
        lpnt = str2 - 1;
}

#ifdef VT100
/*
 *      cursor(x,y)     Subroutine to set the cursor position
 *
 *      x and y are the cursor coordinates, and lpbuff is the output buffer where
 *      escape sequence will be placed.
 */
static const char *y_num[]= { "\33[","\33[","\33[2","\33[3","\33[4","\33[5","\33[6",
        "\33[7","\33[8","\33[9","\33[10","\33[11","\33[12","\33[13","\33[14",
        "\33[15","\33[16","\33[17","\33[18","\33[19","\33[20","\33[21","\33[22",
        "\33[23","\33[24" };

static const char *x_num[]= { "H","H",";2H",";3H",";4H",";5H",";6H",";7H",";8H",";9H",
        ";10H",";11H",";12H",";13H",";14H",";15H",";16H",";17H",";18H",";19H",
        ";20H",";21H",";22H",";23H",";24H",";25H",";26H",";27H",";28H",";29H",
        ";30H",";31H",";32H",";33H",";34H",";35H",";36H",";37H",";38H",";39H",
        ";40H",";41H",";42H",";43H",";44H",";45H",";46H",";47H",";48H",";49H",
        ";50H",";51H",";52H",";53H",";54H",";55H",";56H",";57H",";58H",";59H",
        ";60H",";61H",";62H",";63H",";64H",";65H",";66H",";67H",";68H",";69H",
        ";70H",";71H",";72H",";73H",";74H",";75H",";76H",";77H",";78H",";79H",
        ";80H" };

void
cursor(int x, int y)
{
        char *p;
        if (lpnt >= lpend)
                lflush();

        p = y_num[y];                   /* get the string to print */
        while (*p)
                *lpnt++ = *p++;         /* print the string */

        p = x_num[x];                   /* get the string to print */
        while (*p)
                *lpnt++ = *p++;         /* print the string */
}
#else /* VT100 */
/*
 *      cursor(x,y)     Put cursor at specified coordinates staring at [1,1] (termcap)
 */
void
cursor(int x, int y)
{
        if (lpnt >= lpend)
                lflush();

        *lpnt++ = CURSOR;
        *lpnt++ = x;
        *lpnt++ = y;
}
#endif /* VT100 */

/*
 *      Routine to position cursor at beginning of 24th line
 */
void
cursors(void)
{
        cursor(1, 24);
}

#ifndef VT100
/*
 * Warning: ringing the bell is control code 7. Don't use in defines.
 * Don't change the order of these defines.
 * Also used in helpfiles. Codes used in helpfiles should be \E[1 to \E[7 with
 * obvious meanings.
 */

static char cap[256];
char *CM, *CE, *CD, *CL, *SO, *SE, *AL, *DL;/* Termcap capabilities */
static char *outbuf = NULL;     /* translated output buffer */

/*
 * init_term()          Terminal initialization -- setup termcap info
 */
void
init_term(void)
{
        char  termbuf[1024];
        char *capptr = cap + 10;
        char *term;

        switch (tgetent(termbuf, term = getenv("TERM"))) {
        case -1:
                write(2, "Cannot open termcap file.\n", 26);
                exit(1);
        case 0:
                write(2, "Cannot find entry of ", 21);
                write(2, term, strlen(term));
                write(2, " in termcap\n", 12);
                exit(1);
        }

        CM = tgetstr("cm", &capptr);    /* Cursor motion */
        CE = tgetstr("ce", &capptr);    /* Clear to eoln */
        CL = tgetstr("cl", &capptr);    /* Clear screen */

/* OPTIONAL */
        AL = tgetstr("al", &capptr);    /* Insert line */
        DL = tgetstr("dl", &capptr);    /* Delete line */
        SO = tgetstr("so", &capptr);    /* Begin standout mode */
        SE = tgetstr("se", &capptr);    /* End standout mode */
        CD = tgetstr("cd", &capptr);    /* Clear to end of display */

        if (!CM) {              /* can't find cursor motion entry */
                write(2, "Sorry, for a ", 13);
                write(2, term, strlen(term));
                write(2, ", I can't find the cursor motion entry in termcap\n", 50);
                exit(1);
        }
        if (!CE) {              /* can't find clear to end of line entry */
                write(2, "Sorry, for a ", 13);
                write(2, term, strlen(term));
                write(2, ", I can't find the clear to end of line entry in termcap\n", 57);
                exit(1);
        }
        if (!CL) {              /* can't find clear entire screen entry */
                write(2, "Sorry, for a ", 13);
                write(2, term, strlen(term));
                write(2, ", I can't find the clear entire screen entry in termcap\n", 56);
                exit(1);
        }
        /* get memory for decoded output buffer*/
        if ((outbuf = malloc(BUFBIG + 16)) == NULL) {
                write(2, "Error malloc'ing memory for decoded output buffer\n", 50);
                died(-285);     /* malloc() failure */
        }
}
#endif /* VT100 */

/*
 *      cl_line(x,y)    Clear the whole line indicated by 'y' and leave cursor at [x,y]
 */
void
cl_line(int x, int y)
{
#ifdef VT100
        cursor(x, y);
        lprcat("\33[2K");
#else /* VT100 */
        cursor(1, y);
        *lpnt++ = CL_LINE;
        cursor(x, y);
#endif /* VT100 */
}

/*
 *      cl_up(x,y)      Clear screen from [x,1] to current position. Leave cursor at [x,y]
 */
void
cl_up(int x, int y)
{
#ifdef VT100
        cursor(x, y);
        lprcat("\33[1J\33[2K");
#else /* VT100 */
        int i;
        cursor(1, 1);
        for (i = 1; i <= y; i++) {
                *lpnt++ = CL_LINE;
                *lpnt++ = '\n';
        }
        cursor(x, y);
#endif /* VT100 */
}

/*
 *      cl_dn(x,y)      Clear screen from [1,y] to end of display. Leave cursor at [x,y]
 */
void
cl_dn(int x, int y)
{
#ifdef VT100
        cursor(x, y);
        lprcat("\33[J\33[2K");
#else /* VT100 */
        int i;
        cursor(1, y);
        if (!CD) {
                *lpnt++ = CL_LINE;
                for (i = y; i <= 24; i++) {
                        *lpnt++ = CL_LINE;
                        if (i != 24)
                                *lpnt++ = '\n';
                }
                cursor(x, y);
        } else
                *lpnt++ = CL_DOWN;
        cursor(x, y);
#endif /* VT100 */
}

/*
 *      standout(str)   Print the argument string in inverse video (standout mode).
 */
void
standout(const char *str)
{
#ifdef VT100
        setbold();
        while (*str)
                *lpnt++ = *str++;
        resetbold();
#else /* VT100 */
        *lpnt++ = ST_START;
        while (*str)
                *lpnt++ = *str++;
        *lpnt++ = ST_END;
#endif /* VT100 */
}

/*
 *      set_score_output()      Called when output should be literally printed.
 */
void
set_score_output(void)
{
        enable_scroll = -1;
}

/*
 *      lflush()        Flush the output buffer
 *
 *      Returns nothing of value.
 *      for termcap version: Flush output in output buffer according to output
 *                           status as indicated by `enable_scroll'
 */
#ifndef VT100
static int scrline = 18;        /* line # for wraparound instead of scrolling if no DL */

void
lflush(void)
{
        int lpoint;
        char *str;
        static int curx = 0;
        static int cury = 0;

        if ((lpoint = lpnt - lpbuf) > 0) {
#ifdef EXTRA
                c[BYTESOUT] += lpoint;
#endif
                if (enable_scroll <= -1) {
                        flush_buf();
                        if (write(io_outfd, lpbuf, lpoint) != lpoint)
                                write(2, "error writing to output file\n", 29);
                        lpnt = lpbuf;   /* point back to beginning of buffer */
                        return;
                }
                for (str = lpbuf; str < lpnt; str++) {
                        if (*str >= 32) {
                                putchr(*str);
                                curx++;
                        } else
                                switch (*str) {
                                case CLEAR:
                                        tputs(CL, 0, putchr);
                                        curx = cury = 0;
                                        break;

                                case CL_LINE:
                                        tputs(CE, 0, putchr);
                                        break;

                                case CL_DOWN:
                                        tputs(CD, 0, putchr);
                                        break;

                                case ST_START:
                                        tputs(SO, 0, putchr);
                                        break;

                                case ST_END:
                                        tputs(SE, 0, putchr);
                                        break;

                                case CURSOR:
                                        curx = *++str - 1;
                                        cury = *++str - 1;
                                        tputs(tgoto(CM, curx, cury), 0, putchr);
                                        break;

                                case '\n':
                                        if ((cury == 23) && enable_scroll) {
                                                if (!DL || !AL) {       /* wraparound or scroll? */
                                                        if (++scrline > 23)
                                                                scrline = 19;

                                                        if (++scrline > 23)
                                                                scrline = 19;
                                                        tputs(tgoto(CM, 0, scrline), 0, putchr);
                                                        tputs(CE, 0, putchr);

                                                        if (--scrline < 19)
                                                                scrline = 23;
                                                        tputs(tgoto(CM, 0, scrline), 0, putchr);
                                                        tputs(CE, 0, putchr);
                                                } else {
                                                        tputs(tgoto(CM, 0, 19), 0, putchr);
                                                        tputs(DL, 0, putchr);
                                                        tputs(tgoto(CM, 0, 23), 0, putchr);
                                                }
                                        } else {
                                                putchr('\n');
                                                cury++;
                                        }
                                        curx = 0;
                                        break;

                                default:
                                        putchr(*str);
                                        curx++;
                                }
                }
        }
        lpnt = lpbuf;
        flush_buf();            /* flush real output buffer now */
}
#else /* VT100 */
/*
 *      lflush()        flush the output buffer
 *
 *      Returns nothing of value.
 */
void
lflush(void)
{
        int lpoint;
        if ((lpoint = lpnt - lpbuf) > 0) {
#ifdef EXTRA
                c[BYTESOUT] += lpoint;
#endif
                if (write(io_outfd, lpbuf, lpoint) != lpoint)
                        write(2, "error writing to output file\n", 29);
        }
        lpnt = lpbuf;           /* point back to beginning of buffer */
}
#endif /* VT100 */

#ifndef VT100
static int pindex = 0;
/*
 *      putchr(ch)      Print one character in decoded output buffer.
 */
static int
putchr(int ch)
{
        outbuf[pindex++] = ch;
        if (pindex >= BUFBIG)
                flush_buf();
        return (0);
}

/*
 *      flush_buf()     Flush buffer with decoded output.
 */
static void
flush_buf(void)
{
        if (pindex)
                write(io_outfd, outbuf, pindex);
        pindex = 0;
}

/*
 *      char *tmcapcnv(sd,ss)   Routine to convert VT100 escapes to termcap format
 *
 *      Processes only the \33[#m sequence (converts . files for termcap use
 */
char *
tmcapcnv(char *sd, char *ss)
{
        int tmstate = 0;        /* 0=normal, 1=\33 2=[ 3=# */
        char tmdigit = 0;       /* the # in \33[#m */
        while (*ss) {
                switch (tmstate) {
                case 0:
                        if (*ss == '\33') {
                                tmstate++;
                                break;
                        }
ign:  *sd++ = *ss;
ign2: tmstate = 0;
                        break;
                case 1:
                        if (*ss != '[')
                                goto ign;
                        tmstate++;
                        break;
                case 2:
                        if (isdigit((int)*ss)) {
                                tmdigit = *ss - '0';
                                tmstate++;
                                break;
                        }
                        if (*ss == 'm') {
                                *sd++ = ST_END;
                                goto ign2;
                        }
                        goto ign;
                case 3:
                        if (*ss == 'm') {
                                if (tmdigit)
                                        *sd++ = ST_START;
                                else
                                        *sd++ = ST_END;
                                goto ign2;
                        }
                default:
                        goto ign;
                }
                ss++;
        }
        *sd = 0;        /* NULL terminator */
        return (sd);
}
#endif /* VT100 */

/*
 *      beep()          Routine to emit a beep if enabled (see no-beep in .larnopts)
 */
void
beep(void)
{
        if (!nobeep)
                *lpnt++ = '\7';
}