Usenet 1994 January/usenetsourcesnewsgroupsinfomagicjanuary1994.iso/sources/misc/volume5/grabchars1.3/sys.c

C/C++ Source or Header | 1989-02-03 | 4.3 KB | 220 lines

/*
**    $Header: sys.c,v 1.3 88/12/05 19:46:14 daniel grabchars_1_3 $
**
**    sys.c - terminal routines for grabchars
**
**    Dan Smith ([e-mail]), November 29, 1988
**
**    History:
**
**    December 2, 1988
**    made #ifdefs for DV_ERASE and BSD, wrote notes in handle_erase ()
**    for changes and improvements
*/

#include <stdio.h>
#include <sgtty.h>
#include <signal.h>
#include "grabchars.h"

struct sgttyb orig, new;

/* all declared in globals.c */
extern FILE *outfile, *otherout;
extern FLAG *flags;
extern int exit_stat;
extern char default_string[128];

#ifdef DV_ERASE
extern char *erase_buf;
#endif

/* initialize global flags */
init_flags ()
{
    flags->both = 0;
    flags->check = 0;
    flags->dflt = 0;
    flags->flush = 0;
    flags->ret_key = 0;
    flags->silent = 0;
    flags->erase = 0;
}

/*
**    initialize tty
**
**    this really needs SYS V code...any patchers out there?
*/
init_term ()
{
    /*    play havoc with the terminal :-) */

#ifdef BSD
    ioctl (0, TIOCGETP, &orig);
    new = orig;
    new.sg_flags &= ~ECHO;
    new.sg_flags |= CBREAK;

    (flags->flush) ? ioctl (0, TIOCSETP, &new) :    /* to flush... */
        ioctl (0, TIOCSETN, &new);        /* ...or not to flush */
#endif
}

/* handle the outside world */
init_signal ()
{
    int lets_go ();

    signal (SIGINT, lets_go);
    signal (SIGTSTP, lets_go);
    signal (SIGQUIT, lets_go);
}

/*
**    something's up with the user...give a useful exit status so
**    we can ask things like "do you need help?"
*/
int overtime ()
{
    int lets_go ();
    void handle_default ();

    /* does not return */
    if (exit_stat == -1 && flags->dflt)
        handle_default ();

    exit_stat = -2;
    lets_go ();
}

/*
**    the default_flag is set, and the user either typed a return
**    or timed out.  This routine does not return.
*/
void handle_default ()
{
    int lets_go ();

    if (! flags->silent) {
        fputs (default_string, outfile);
        if (flags->both)
            fputs (default_string, otherout);
    }
    exit_stat = strlen (default_string);
    lets_go ();
}

/*    clean up and get out of here... */
int lets_go ()
{
#ifdef BSD
    ioctl (0, TIOCSETP, &orig);
#endif
    exit (exit_stat);
}

#ifdef DV_ERASE

/*
**    December 2, 1988
**    Bucko's (daniel) in progress notes for changing this...
**
**    first time through processing should be called as its' own
**    function from the -E case in the main (getopt ()) switch...
**
**    stdout and stderr should never be affected by any erasures...
**    (they probably are not now, I haven't thoroughly tested this...)
**
**    I need to drag in my word erase routine; never can tell how
**    long some people are going to want their lines with -n! :-)
**
**    If someone wants a control char (via literal (^V)), we should
**    give it to them...this would be more compatible with $< (csh)
**    and read (sh)... grabchars almost completely replaces these
**    now.
**
**    we can also be sensitive to pipe/no pipe via isatty ()...
*/

/*    DV: handle erase characters, kill characters, etc. */
handle_erase (ch, cnt)
char ch;
int *cnt;
{
    static char first = 1;
    static char erasec, killc, werasec, lnextc, rprntc;
    static char lnextflg = 0;
    static char *cp;
    static FILE *tty;
    int i;

    if (first) {
        /* initialize static things */
        struct sgttyb sb;
        struct ltchars ltc;

        first = 0;
        cp = erase_buf;
        tty = fopen ("/dev/tty", "w");

        /* . this isn't going to do... what if -e is set?...dan */
        if (tty == NULL)
            tty = stderr;
        ioctl (0, TIOCGETP, &sb);
        ioctl (0, TIOCGLTC, <c);
        erasec = sb.sg_erase;
        killc = sb.sg_kill;
        werasec = ltc.t_werasc;
        lnextc = ltc.t_lnextc;
        rprntc = ltc.t_rprntc;
    }

    if (lnextflg) {
        ch |= 0x80;
        lnextflg = 0;
    }
    (*cnt) --;
    if (ch == erasec) {
        if (*cnt < 0)
            return;
        fprintf (tty, "\b \b");
        (*cnt) --;
        *--cp = 0;
    } else if (ch == killc) {
        while (*cnt >= 0) {
            fprintf (tty, "\b \b");
            (*cnt) --;
            *--cp = 0;
        }
    } else if (ch == werasec) {
        if (*cnt < 0)
            return;
        while ((cp[-1] == ' ' || cp[-1] == '\t') && (*cnt) >= 0) {
            fprintf (tty, "\b");
            (*cnt) --;
            *--cp = 0;
        }
        while (cp[-1] != ' ' && cp[-1] != '\t' && (*cnt) >= 0) {
            fprintf (tty, "\b \b");
            (*cnt) --;
            *--cp = 0;
        }
    } else if (ch == lnextc) {
        lnextflg = 1;
        fprintf (tty, "^\b");
    } else if (ch == rprntc) {
        for (i = strlen (erase_buf); i > 0; i--)
            putc ('\b', tty);
        fprintf (tty, "%s", erase_buf);
    } else {
        ch &= 0x7f;
        fprintf (tty, "%c", ch);
        *cp++ = ch;
        (*cnt) ++;
    }
    fflush (tty);
    return;
}
#endif