/* Copyright (C) 1998, 1999 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Zack Weinberg <zack@rabi.phys.columbia.edu>, 1998. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with the GNU C Library; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include <errno.h> #include <fcntl.h> #include <string.h> #include <unistd.h> /* Prefix for master pseudo terminal nodes. */ #define _PATH_PTY "/dev/pty" /* Letters indicating a series of pseudo terminals. */ #ifndef PTYNAME1 #define PTYNAME1 "pqrsPQRS" #endif const char _ptyname1[] = PTYNAME1; /* Letters indicating the position within a series. */ #ifndef PTYNAME2 #define PTYNAME2 "0123456789abcdefghijklmnopqrstuv"; #endif const char _ptyname2[] = PTYNAME2; /* Open a master pseudo terminal and return its file descriptor. */ int __getpt (void) { char buf[sizeof (_PATH_PTY) + 2]; const char *p, *q; char *s; memcpy (buf, _PATH_PTY, sizeof (_PATH_PTY)); s = buf + strlen (buf); /* s[0] and s[1] will be filled in the loop. */ s[2] = '\0'; for (p = _ptyname1; *p != '\0'; ++p) { s[0] = *p; for (q = _ptyname2; *q != '\0'; ++q) { int fd; s[1] = *q; fd = open (buf, O_RDWR); if (fd != -1) return fd; if (errno == ENOENT) return -1; } } errno = ENOENT; return -1; }