src/include/openpty.c

   1  /*
   2  * openpty: glibc implementation
   3  *
   4  * Copyright (C) 1998, 1999, 2004 Free Software Foundation, Inc.
   5  *
   6  * Authors:
   7  * Zack Weinberg <zack@rabi.phys.columbia.edu>, 1998.
   8  *
   9  *  This library is free software; you can redistribute it and/or
  10  *  modify it under the terms of the GNU Lesser General Public
  11  *  License as published by the Free Software Foundation; either
  12  *  version 2.1 of the License, or (at your option) any later version.
  13
  14  *  This library is distributed in the hope that it will be useful,
  15  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  *  Lesser General Public License for more details.
  18
  19  *  You should have received a copy of the GNU Lesser General Public
  20  *  License along with this library; if not, write to the Free Software
  21  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  22  */
  23
  24 #define _XOPEN_SOURCE       /* See feature_test_macros(7) */
  25 #include <errno.h>
  26 #include <fcntl.h>
  27 #include <limits.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include <termios.h>
  31 #include <unistd.h>
  32 #include <sys/types.h>
  33 #include <sys/ioctl.h>
  34
  35 #define _PATH_DEVPTMX "/dev/ptmx"
  36
  37 int openpty (int *amaster, int *aslave, char *name, struct termios *termp,
  38        struct winsize *winp)
  39 {
  40    char buf[PATH_MAX];
  41    int master, slave;
  42
  43    master = open(_PATH_DEVPTMX, O_RDWR);
  44    if (master == -1)
  45        return -1;
  46
  47    if (grantpt(master))
  48        goto fail;
  49
  50    if (unlockpt(master))
  51        goto fail;
  52
  53    if (ptsname_r(master, buf, sizeof buf))
  54        goto fail;
  55
  56    slave = open(buf, O_RDWR | O_NOCTTY);
  57    if (slave == -1)
  58        goto fail;
  59
  60    /* XXX Should we ignore errors here?  */
  61    if (termp)
  62        tcsetattr(slave, TCSAFLUSH, termp);
  63    if (winp)
  64        ioctl(slave, TIOCSWINSZ, winp);
  65
  66    *amaster = master;
  67    *aslave = slave;
  68    if (name != NULL)
  69        strcpy(name, buf);
  70
  71    return 0;
  72
  73 fail:
  74    close(master);
  75    return -1;
  76 }