Ronny Chevalier <chevalier.ronny@gmail.com>shared: add terminal-util.[ch]

Signed-off-by: Anthony G. Basile <blueness@gentoo.org>

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;
+}