1 /* Open the master side of a pseudo-terminal. 2 Copyright (C) 2010-2021 Free Software Foundation, Inc. 3 4 This file is free software: you can redistribute it and/or modify 5 it under the terms of the GNU Lesser General Public License as 6 published by the Free Software Foundation; either version 2.1 of the 7 License, or (at your option) any later version. 8 9 This file is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 GNU Lesser General Public License for more details. 13 14 You should have received a copy of the GNU Lesser General Public License 15 along with this program. If not, see <https://www.gnu.org/licenses/>. */ 16 17 #include <config.h> 18 19 /* Specification. */ 20 #include <stdlib.h> 21 22 #include <errno.h> 23 #include <fcntl.h> 24 #if defined __OpenBSD__ 25 # include <sys/ioctl.h> 26 # include <sys/tty.h> 27 #endif 28 29 /* posix_openpt() is already provided on 30 glibc >= 2.2.1 (but is a stub on GNU/Hurd), 31 Mac OS X >= 10.4, 32 FreeBSD >= 5.1 (lived in src/lib/libc/stdlib/grantpt.c before 8.0), 33 NetBSD >= 3.0, 34 AIX >= 5.2, HP-UX >= 11.31, Solaris >= 10, Cygwin >= 1.7. 35 Thus, this replacement function is compiled on 36 Mac OS X 10.3, OpenBSD 4.9, Minix 3.1.8, 37 AIX 5.1, HP-UX 11.23, IRIX 6.5, OSF/1 5.1, Solaris 9, 38 Cygwin 1.5.x, mingw, MSVC 9, Interix 3.5, BeOS. 39 Among these: 40 - AIX has /dev/ptc. 41 - HP-UX 10..11, IRIX 6.5, OSF/1 5.1, Solaris 2.6..9, Cygwin 1.5 42 have /dev/ptmx. 43 - HP-UX 10..11 also has /dev/ptym/clone, but this should not be needed. 44 - OpenBSD 4.9 has /dev/ptm and the PTMGET ioctl. 45 - Minix 3.1.8 have a list of pseudo-terminal devices in /dev. 46 - On native Windows, there are no ttys at all. */ 47 48 int 49 posix_openpt (int flags) /* */ 50 { 51 int master; 52 53 #ifdef _AIX /* AIX */ 54 55 master = open ("/dev/ptc", flags); 56 57 #elif defined _WIN32 && !defined __CYGWIN__ /* mingw */ 58 59 /* Mingw lacks pseudo-terminals altogether. */ 60 master = -1; 61 errno = ENOSYS; 62 63 #elif defined __OpenBSD__ 64 65 /* On OpenBSD, master and slave of a pseudo-terminal are allocated together, 66 by opening /dev/ptm and applying the PTMGET ioctl to it. */ 67 int fd; 68 struct ptmget data; 69 70 fd = open (PATH_PTMDEV, O_RDWR); 71 if (fd >= 0) 72 { 73 if (ioctl (fd, PTMGET, &data) >= 0) 74 { 75 master = data.cfd; 76 close (data.sfd); 77 close (fd); 78 } 79 else 80 { 81 int saved_errno = errno; 82 close (fd); 83 errno = saved_errno; 84 master = -1; 85 } 86 } 87 else 88 master = -1; 89 90 #else /* Mac OS X, Minix, HP-UX, IRIX, OSF/1, Solaris 9, Cygwin 1.5 */ 91 92 /* Most systems that lack posix_openpt() have /dev/ptmx. */ 93 master = open ("/dev/ptmx", flags); 94 95 /* If all this does not work, we could try to open, one by one: 96 - On Mac OS X: /dev/pty[p-w][0-9a-f] 97 - On *BSD: /dev/pty[p-sP-S][0-9a-v] 98 - On Minix: /dev/pty[p-q][0-9a-f] 99 - On AIX: /dev/ptyp[0-9a-f] 100 - On HP-UX: /dev/pty[p-r][0-9a-f] 101 - On OSF/1: /dev/pty[p-q][0-9a-f] 102 - On Solaris: /dev/pty[p-r][0-9a-f] 103 */ 104 105 #endif 106 107 return master; 108 }