| /* Assign a given terminal as controlling terminal and as standard input, |
| standard output, standard error of the current process. |
| Copyright (C) 2010-2020 Free Software Foundation, Inc. |
| |
| This program is free software: you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program 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 General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <https://www.gnu.org/licenses/>. */ |
| |
| #include <config.h> |
| |
| /* Currently no specification header. */ |
| |
| #include <fcntl.h> |
| #include <unistd.h> |
| #include <sys/ioctl.h> |
| |
| int |
| login_tty (int slave_fd) |
| { |
| int i; |
| |
| /* Create a new session. */ |
| setsid (); |
| |
| /* Make fd the controlling terminal for the current process. |
| On BSD and OSF/1: There is ioctl TIOCSCTTY for this purpose. |
| On Solaris: |
| A terminal becomes the controlling terminal of a session |
| if it is being open()ed, at a moment when |
| 1. it is not already the controlling terminal of some session, and |
| 2. the process that open()s it is a session leader that does not have |
| a controlling terminal. |
| We assume condition 1, try to ensure condition 2, and then open() it. |
| */ |
| for (i = 0; i < 3; i++) |
| if (i != slave_fd) |
| close (i); |
| #ifdef TIOCSCTTY |
| if (ioctl (slave_fd, TIOCSCTTY, NULL) < 0) |
| return -1; |
| #else |
| { |
| char *slave_name; |
| int dummy_fd; |
| |
| slave_name = ttyname (slave_fd); |
| if (slave_name == NULL) |
| return -1; |
| dummy_fd = open (slave_name, O_RDWR); |
| if (dummy_fd < 0) |
| return -1; |
| close (dummy_fd); |
| } |
| #endif |
| |
| /* Assign fd to the standard input, standard output, and standard error of |
| the current process. */ |
| for (i = 0; i < 3; i++) |
| if (slave_fd != i) |
| if (dup2 (slave_fd, i) < 0) |
| return -1; |
| if (slave_fd >= 3) |
| close (slave_fd); |
| |
| return 0; |
| } |