[pacman-dev] [PATCH] Revamp pacman signal handler

[Dan McGee]

* All errors now go to stdout, so do the same here and simplify the
  writing of the error message.
* Add SIGHUP to the handled signal list, and don't repeat code.
* Attempt to release the transaction (e.g. remove the lock file)
  for all of HUP, INT, and TERM. Signals HUP and INT respects
  transaction state, TERM will immediately terminate the process.

Signed-off-by: Dan McGee <dan at archlinux.org>
---
 src/pacman/pacman.c |   46 +++++++++++++++++++++++-----------------------
 1 files changed, 23 insertions(+), 23 deletions(-)

diff --git a/src/pacman/pacman.c b/src/pacman/pacman.c
index 061d593..40aa444 100644
--- a/src/pacman/pacman.c
+++ b/src/pacman/pacman.c
@@ -299,26 +299,29 @@ static void handler(int signum)
 {
 	int out = fileno(stdout);
 	int err = fileno(stderr);
+	const char *msg;
 	if(signum == SIGSEGV) {
-		const char *msg1 = "error: segmentation fault\n";
-		const char *msg2 = "Internal pacman error: Segmentation fault.\n"
+		msg = "\nerror: segmentation fault\n"
 			"Please submit a full bug report with --debug if appropriate.\n";
-		/* write a error message to out, the rest to err */
-		xwrite(out, msg1, strlen(msg1));
-		xwrite(err, msg2, strlen(msg2));
+		xwrite(err, msg, strlen(msg));
 		exit(signum);
-	} else if(signum == SIGINT) {
-		const char *msg = "\nInterrupt signal received\n";
+	} else if(signum == SIGINT || signum == SIGHUP) {
+		if(signum == SIGINT) {
+			msg = "\nInterrupt signal received\n";
+		} else {
+			msg = "\nHangup signal received\n";
+		}
 		xwrite(err, msg, strlen(msg));
 		if(alpm_trans_interrupt(config->handle) == 0) {
 			/* a transaction is being interrupted, don't exit pacman yet. */
 			return;
 		}
-		/* no commiting transaction, we can release it now and then exit pacman */
-		alpm_trans_release(config->handle);
-		/* output a newline to be sure we clear any line we may be on */
-		xwrite(out, "\n", 1);
 	}
+	/* SIGINT: no commiting transaction, release it now and then exit pacman
+	 * SIGHUP, SIGTERM: release no matter what */
+	alpm_trans_release(config->handle);
+	/* output a newline to be sure we clear any line we may be on */
+	xwrite(out, "\n", 1);
 	cleanup(128 + signum);
 }
 
@@ -757,8 +760,9 @@ static void cl_to_log(int argc, char* argv[])
  */
 int main(int argc, char *argv[])
 {
-	int ret = 0;
+	int i, ret = 0;
 	struct sigaction new_action, old_action;
+	const int signals[] = { SIGHUP, SIGINT, SIGTERM, SIGSEGV };
 #if defined(HAVE_GETEUID) && !defined(CYGWIN)
 	/* geteuid undefined in CYGWIN */
 	uid_t myuid = geteuid();
@@ -775,17 +779,13 @@ int main(int argc, char *argv[])
 	sigemptyset(&new_action.sa_mask);
 	new_action.sa_flags = 0;
 
-	sigaction(SIGINT, NULL, &old_action);
-	if(old_action.sa_handler != SIG_IGN) {
-		sigaction(SIGINT, &new_action, NULL);
-	}
-	sigaction(SIGTERM, NULL, &old_action);
-	if(old_action.sa_handler != SIG_IGN) {
-		sigaction(SIGTERM, &new_action, NULL);
-	}
-	sigaction(SIGSEGV, NULL, &old_action);
-	if(old_action.sa_handler != SIG_IGN) {
-		sigaction(SIGSEGV, &new_action, NULL);
+	/* assign our handler to any signals we care about */
+	for(i = 0; i < sizeof(signals) / sizeof(signals[0]); i++) {
+		int signal = signals[i];
+		sigaction(signal, NULL, &old_action);
+		if(old_action.sa_handler != SIG_IGN) {
+			sigaction(signal, &new_action, NULL);
+		}
 	}
 
 	/* i18n init */
-- 
1.7.6.3