[hackers] [st][PATCH] externalpipe sigaction

From: Christian Tenllado <ctenllado_AT_gmail.com>
Date: Sat, 18 Apr 2020 20:57:37 +0200

This patch should be applied on top of the externalpipe patch. It
prevents the reset of the signal handler set on SIGCHILD, when the
forked process that executes the external process exits. I opted for
switching from signal to sigaction instead of rearming the signal in the
sigchld function, just because it is the recommended function (although I
tried both ways and both worked).

---
 st.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/st.c b/st.c
index ab291ac..0824894 100644
--- a/st.c
+++ b/st.c
_AT_@ -712,7 +712,7 @@ sigchld(int a)
 	int stat;
 	pid_t p;
 
-	if ((p = waitpid(pid, &stat, WNOHANG)) < 0)
+	if ((p = waitpid(-1, &stat, WNOHANG)) < 0)
 		die("waiting for pid %hd failed: %s\n", pid, strerror(errno));
 
 	if (pid != p)
_AT_@ -753,6 +753,7 @@ int
 ttynew(char *line, char *cmd, char *out, char **args)
 {
 	int m, s;
+	struct sigaction sa;
 
 	if (out) {
 		term.mode |= MODE_PRINT;
_AT_@ -804,7 +805,10 @@ ttynew(char *line, char *cmd, char *out, char **args)
 #endif
 		close(s);
 		cmdfd = m;
-		signal(SIGCHLD, sigchld);
+		memset(&sa, 0, sizeof(sa));
+		sigemptyset(&sa.sa_mask);
+		sa.sa_handler = sigchld;
+		sigaction(SIGCHLD, &sa, NULL);
 		break;
 	}
 	return cmdfd;
-- 
2.20.1

Received on Sat Apr 18 2020 - 20:57:37 CEST