tty.c

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/* $Id: tty.c,v 1.1 2003/04/17 17:42:43 czz Exp $ */

/*
 * TTY.C ------ Routines for pseudo terminal allocation.
 *		Various platforms are supported.
 *
 * Copyright (C) 1992, 1993  Yongguang Zhang
 * All right reserved.		([e-mail])
 */

#ifndef lint
static char *rcs_id = "$Id: tty.c,v 1.1 2003/04/17 17:42:43 czz Exp $";
#endif                          /* lint */

#include "config.h"

/* 
 * Functions get_pty() and pty_search() in this file are adopted from
 * X11R5 xterm, copyrighted by DEC & MIT.
 */

#ifdef hpux
# define	PTYCHAR1	"zyxwvutsrqp"
# define	PTYCHAR2	"fedcba9876543210"
# define	PTYDEV		"/dev/ptym/ptyxx"
# define	TTYDEV		"/dev/pty/ttyxx"
#else                           /* !hpux */
# define	PTYCHAR1	"pqrstuvwxyzPQRSTUVWXYZ"
# define	PTYCHAR2	"0123456789abcdef"
# define	PTYDEV		"/dev/ptyxx"
# define	TTYDEV		"/dev/ttyxx"
#endif                          /* !hpux */

#ifdef	SYSV
extern char *ptsname();
#endif

#ifdef hpux
# include <sys/utsname.h>
#endif

static char ptydev[32];
static char ttydev[32];
static int pty_search();

/* This function opens up a pty master and stuffs its value into pty.
 * If it finds one, it returns a value of 0.  If it does not find one,
 * it returns a value of !0.  This routine is designed to be re-entrant,
 * so that if a pty master is found and later, we find that the slave
 * has problems, we can re-enter this function and get another one.
 */

int get_pty(pty)
int *pty;
{
    strcpy(ptydev, PTYDEV);
    strcpy(ttydev, TTYDEV);

#if defined(SYSV) && defined(SYSV386)
    if (pty_search(pty) == 0)
        return 0;
#endif                          /* SYSV && SYSV386 */

#if (defined(att) || defined(ATT)) && (!defined(_SEQUENT_))
    {
        if ((*pty = open("/dev/ptmx", O_RDWR)) < 0)
            return 1;
# if defined(SVR4) || defined(SYSV386)
        strcpy(ttydev, ptsname(*pty));
# endif
        return 0;
    }
# define GET_PTY_DONE
#endif                          /* ATT */

#if defined(AIXV3) || defined(_IBMR2)
    {
        if ((*pty = open("/dev/ptc", O_RDWR)) < 0)
            return 1;
        strcpy(ttydev, (char *) ttyname(*pty));
        return 0;
    }
# define GET_PTY_DONE
#endif

#if defined(sgi) && (IRIX >= 4)
    {
        char *tty_name;

        tty_name = _getpty(pty, O_RDWR, 0622, 0);
        if (tty_name == 0)
            return 1;
        strcpy(ttydev, tty_name);
        return 0;
    }
# define GET_PTY_DONE
#endif

#ifdef __convex__
    {
        char *pty_name, *getpty();

        while ((pty_name = getpty()) != NULL) {
            if ((*pty = open(pty_name, O_RDWR)) >= 0) {
                strcpy(ptydev, pty_name);
                strcpy(ttydev, pty_name);
                ttydev[5] = 't';
                return 0;
            }
        }
        return 1;
    }
# define GET_PTY_DONE
#endif                          /* __convex__ */

#if defined(sequent) || defined(_SEQUENT_)
    {
        char *sl[2], *ms[2];

        *pty = getpseudotty(sl, ms);
        strcpy(ptydev, ms[0]);
        strcpy(ttydev, sl[0]);
        return (*pty >= 0 ? 0 : 1);
    }
# define GET_PTY_DONE
#endif                          /* sequent */

#if (defined(sgi) && (IRIX == 3)) || (defined(umips) && defined (SYSTYPE_SYSV))
    {
        struct stat fstat_buf;
        int tty;

        *pty = open("/dev/ptc", O_RDWR);
        if (*pty < 0 || (fstat(*pty, &fstat_buf)) < 0) {
            return (1);
        }
        sprintf(ttydev, "/dev/ttyq%d", minor(fstat_buf.st_rdev));
# ifndef sgi
        sprintf(ptydev, "/dev/ptyq%d", minor(fstat_buf.st_rdev));
        if ((*tty = open(ttydev, O_RDWR)) < 0) {
            close(*pty);
            return (1);
        }
# endif                         /* !sgi */
        /*
         * got one! 
         */
        return (0);
    }
# define GET_PTY_DONE
#endif                          /* sgi or umips */

#ifndef	GET_PTY_DONE
    return pty_search(pty);
#endif

}

/*
 * Called from get_pty to iterate over likely pseudo terminals
 * we might allocate.  Used on those systems that do not have
 * a functional interface for allocating a pty.
 * Returns 0 if found a pty, 1 if fails.
 */
static int pty_search(pty)
int *pty;
{
    static int devindex, letter = 0;

#ifdef	O_NOCTTY
# define	O_RDWRPTY	(O_RDWR | O_NOCTTY)
#else
# define	O_RDWRPTY	(O_RDWR)
#endif

#ifdef CRAY
    for (; devindex < 256; devindex++) {
        sprintf(ttydev, "/dev/ttyp%03d", devindex);
        sprintf(ptydev, "/dev/pty/%03d", devindex);

        if ((*pty = open(ptydev, O_RDWRPTY)) >= 0) {
            /*
             * We need to set things up for our next entry
             * * into this function!
             */
            (void) devindex++;
# ifdef	TIOCEXCL
            ioctl(*pty, TIOCEXCL, (char *) 0);
# endif
            return 0;
        }
    }
#else                           /* CRAY */
    while (PTYCHAR1[letter]) {
        ttydev[strlen(ttydev) - 2] = PTYCHAR1[letter];
        ptydev[strlen(ptydev) - 2] = PTYCHAR1[letter];

        while (PTYCHAR2[devindex]) {
            ttydev[strlen(ttydev) - 1] = PTYCHAR2[devindex];
            ptydev[strlen(ptydev) - 1] = PTYCHAR2[devindex];

            if ((*pty = open(ptydev, O_RDWRPTY)) >= 0) {
                /*
                 * We need to set things up for our next entry
                 * * into this function!
                 */
# ifdef sun
                int dummy;

                ptydev[5] = 't';
                chown(ptydev, 0, 0);
                chmod(ptydev, 0600);
                ptydev[5] = 'p';
                if ((ioctl(*pty, TIOCGPGRP, &dummy) == -1) && errno == EIO) {
                    (void) devindex++;
                    return 0;
                }
                close(*pty);
# else
                (void) devindex++;
#  ifdef TIOCEXCL
                ioctl(*pty, TIOCEXCL, (char *) 0);
#  endif
                return 0;
# endif
            }
            devindex++;
        }
        devindex = 0;
        letter++;
    }
#endif                          /* CRAY else */
    /*
     * We were unable to allocate a pty master!  Return an error
     * condition and let our caller terminate cleanly.
     */
    return 1;
}

/* given master fildes, get the slave side tty */
int get_tty(master, tty)
int master;
int *tty;
{
    int t;

#if defined(POSIX) || defined(SVR4) || defined(__convex__)
    int pgrp = setsid();
#else
    int pgrp = getpid();
#endif

#ifdef	USE_PTYS

    setpgrp();
    grantpt(master);
    unlockpt(master);
    if ((*tty = open(ptsname(master), O_RDWR)) < 0)
        return 1;               /* error */

    if (ioctl(*tty, I_PUSH, "ptem") < 0)
        return 1;               /* error */
# if !defined(SVR4) && !defined(SYSV386)
    if (!getenv("CONSEM") && ioctl(*tty, I_PUSH, "consem") < 0) {
        return 1;
# endif
        if (ioctl(*tty, I_PUSH, "ldterm") < 0)
            return 1;
# ifdef SVR4
        if (ioctl(*tty, I_PUSH, "ttcompat") < 0)
            return 1;
# endif

#else                           /* ! USE_PTYS */

# ifdef	TIOCNOTTY
    t = open("/dev/tty", O_RDWR);
    if (t >= 0) {
        (void) ioctl(t, TIOCNOTTY, (char *) 0);
        (void) close(t);
    }
# endif

    *tty = open(ttydev, O_RDWR);
    if (*tty < 0) {
        perror(ttydev);
        return 1;
    }
# ifdef _POSIX_JOB_CONTROL
    if (tcsetpgrp(*tty, pgrp) < 0) {
# endif
# ifdef SYSV
        setpgrp();
# else
#  ifdef TIOCSCTTY
        (void) setsid();
        (void) ioctl(*tty, TIOCSCTTY, 0);
#  endif
#  ifdef TIOCSPGRP
        (void) ioctl(*tty, TIOCSPGRP, (char *) &pgrp);
#  endif
        setpgrp(0, 0);
        close(open(ttydev, O_WRONLY, 0));
        setpgrp(0, pgrp);
# endif                         /* SYSV */
# ifdef _POSIX_JOB_CONTROL
    }
# endif