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-rw-r--r--src/shared/terminal-util.c87
1 files changed, 87 insertions, 0 deletions
diff --git a/src/shared/terminal-util.c b/src/shared/terminal-util.c
new file mode 100644
index 0000000000..04c871a3f7
--- /dev/null
+++ b/src/shared/terminal-util.c
@@ -0,0 +1,87 @@
+/***
+ This file is part of systemd.
+
+ Copyright 2010 Lennart Poettering
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ systemd 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <termios.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <time.h>
+#include <assert.h>
+#include <poll.h>
+#include <linux/vt.h>
+#include <linux/tiocl.h>
+#include <linux/kd.h>
+
+#include "terminal-util.h"
+#include "time-util.h"
+#include "process-util.h"
+#include "util.h"
+#include "fileio.h"
+#include "path-util.h"
+
+static volatile unsigned cached_columns = 0;
+static volatile unsigned cached_lines = 0;
+
+int open_terminal(const char *name, int mode) {
+ int fd, r;
+ unsigned c = 0;
+
+ /*
+ * If a TTY is in the process of being closed opening it might
+ * cause EIO. This is horribly awful, but unlikely to be
+ * changed in the kernel. Hence we work around this problem by
+ * retrying a couple of times.
+ *
+ * https://bugs.launchpad.net/ubuntu/+source/linux/+bug/554172/comments/245
+ */
+
+ assert(!(mode & O_CREAT));
+
+ for (;;) {
+ fd = open(name, mode, 0);
+ if (fd >= 0)
+ break;
+
+ if (errno != EIO)
+ return -errno;
+
+ /* Max 1s in total */
+ if (c >= 20)
+ return -errno;
+
+ usleep(50 * USEC_PER_MSEC);
+ c++;
+ }
+
+ r = isatty(fd);
+ if (r < 0) {
+ safe_close(fd);
+ return -errno;
+ }
+
+ if (!r) {
+ safe_close(fd);
+ return -ENOTTY;
+ }
+
+ return fd;
+}