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authorThomas White <taw@physics.org>2014-08-19 14:22:22 +0200
committerThomas White <taw@physics.org>2014-08-19 14:47:44 +0200
commit7ae6605846ecc70c937fca31b2133082aae055df (patch)
tree00bcacb21248f86caf91a02c55bc5178a52cd27f /lib/login_tty.c
parent1a532028cb2f2df6f12e518bdf6d3425bbb28b08 (diff)
Use Gnulib forkpty()
Diffstat (limited to 'lib/login_tty.c')
-rw-r--r--lib/login_tty.c75
1 files changed, 75 insertions, 0 deletions
diff --git a/lib/login_tty.c b/lib/login_tty.c
new file mode 100644
index 00000000..e07f1607
--- /dev/null
+++ b/lib/login_tty.c
@@ -0,0 +1,75 @@
+/* Assign a given terminal as controlling terminal and as standard input,
+ standard output, standard error of the current process.
+ Copyright (C) 2010-2014 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 <http://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;
+}