ash: optional support for $TMOUT variable
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/shell/ash.c b/shell/ash.c
index 0e27a07..bdc6479 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -97,6 +97,14 @@
//config: help
//config: Enable bash-compatible extensions.
//config:
+//config:config ASH_IDLE_TIMEOUT
+//config: bool "Idle timeout variable"
+//config: default n
+//config: depends on ASH
+//config: help
+//config: Enables bash-like auto-logout after "$TMOUT" seconds
+//config: of idle time.
+//config:
//config:config ASH_JOB_CONTROL
//config: bool "Job control"
//config: default y
@@ -12048,6 +12056,23 @@
return exitstatus;
}
+#if ENABLE_ASH_IDLE_TIMEOUT
+static smallint timed_out;
+
+static void alrm_sighandler(int sig UNUSED_PARAM)
+{
+ /* Close stdin, making interactive command reading stop.
+ * Otherwise, timeout doesn't trigger until <Enter> is pressed.
+ */
+ int sv = errno;
+ close(0);
+ open("/dev/null", O_RDONLY);
+ errno = sv;
+
+ timed_out = 1;
+}
+#endif
+
/*
* Read and execute commands.
* "Top" is nonzero for the top level command loop;
@@ -12064,6 +12089,20 @@
TRACE(("cmdloop(%d) called\n", top));
for (;;) {
int skip;
+#if ENABLE_ASH_IDLE_TIMEOUT
+ int tmout_seconds = 0;
+
+ if (top && iflag) {
+ const char *tmout_var = lookupvar("TMOUT");
+ if (tmout_var) {
+ tmout_seconds = atoi(tmout_var);
+ if (tmout_seconds > 0) {
+ signal(SIGALRM, alrm_sighandler);
+ alarm(tmout_seconds);
+ }
+ }
+ }
+#endif
setstackmark(&smark);
#if JOBS
@@ -12076,6 +12115,14 @@
chkmail();
}
n = parsecmd(inter);
+#if ENABLE_ASH_IDLE_TIMEOUT
+ if (timed_out) {
+ printf("\007timed out waiting for input: auto-logout\n");
+ break;
+ }
+ if (tmout_seconds > 0)
+ alarm(0);
+#endif
#if DEBUG
if (DEBUG > 2 && debug && (n != NODE_EOF))
showtree(n);