cttyhack: don't do anything if ctty is already available
function old new delta
cttyhack_main 244 269 +25
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/shell/cttyhack.c b/shell/cttyhack.c
index 572a3af..bde2acd 100644
--- a/shell/cttyhack.c
+++ b/shell/cttyhack.c
@@ -53,23 +53,32 @@
}
strcpy(console, "/dev/tty");
- if (ioctl(0, TIOCGSERIAL, &u.sr) == 0) {
- /* this is a serial console */
- sprintf(console + 8, "S%d", u.sr.line);
- } else if (ioctl(0, VT_GETSTATE, &u.vt) == 0) {
- /* this is linux virtual tty */
- sprintf(console + 8, "S%d" + 1, u.vt.v_active);
- }
-
- if (console[8]) {
- fd = xopen(console, O_RDWR);
- //bb_error_msg("switching to '%s'", console);
- dup2(fd, 0);
- dup2(fd, 1);
- dup2(fd, 2);
- while (fd > 2) close(fd--);
- /* Some other session may have it as ctty. Steal it from them */
- ioctl(0, TIOCSCTTY, 1);
+ fd = open(console, O_RDWR);
+ if (fd >= 0) {
+ /* We already have ctty, nothing to do */
+ close(fd);
+ } else {
+ /* We don't have ctty (or don't have "/dev/tty" node...) */
+ if (ioctl(0, TIOCGSERIAL, &u.sr) == 0) {
+ /* this is a serial console */
+ sprintf(console + 8, "S%d", u.sr.line);
+ } else if (ioctl(0, VT_GETSTATE, &u.vt) == 0) {
+ /* this is linux virtual tty */
+ sprintf(console + 8, "S%d" + 1, u.vt.v_active);
+ }
+ if (console[8]) {
+ fd = xopen(console, O_RDWR);
+ //bb_error_msg("switching to '%s'", console);
+ dup2(fd, 0);
+ dup2(fd, 1);
+ dup2(fd, 2);
+ while (fd > 2)
+ close(fd--);
+ /* Some other session may have it as ctty,
+ * steal it from them:
+ */
+ ioctl(0, TIOCSCTTY, 1);
+ }
}
BB_EXECVP(argv[0], argv);