gawk

commit 4761f90bc5e5e5a15e0b160e0a2a486969d7a223
parent 7ee4156793eb3f5f7f47528ab32721be4c507324
Author: Jacob R. Edwards <jacobouno@protonmail.com>
Date:   Wed, 23 Dec 2020 22:11:22 -0800

Handle signals and zombies

Diffstat:
M
config.def.h
 | 
3
+++
M
main.c
 | 
33
++++++++++++++++++++++++++-------

2 files changed, 29 insertions(+), 7 deletions(-)
diff --git a/config.def.h b/config.def.h
@@ -3,6 +3,9 @@
 /* default gopher hole (path, host, port): */
 static const char *default_address[] = { "/", "localhost", "70" };
 
+/* signals to handle */
+static const int signals[] = { SIGABRT, SIGCHLD, SIGINT, SIGTERM };
+
 #define IFS	":\t "	/* input field seporator */
 #define ISS	";\n"	/* input statement seporator */
 
diff --git a/main.c b/main.c
@@ -17,6 +17,7 @@
 
 #include <sys/socket.h>
 #include <sys/stat.h>
+#include <sys/wait.h>
 #include <ctype.h>
 #include <err.h>
 #include <errno.h>
@@ -24,6 +25,7 @@
 #include <limits.h>
 #include <netdb.h>
 #include <poll.h>
+#include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -665,31 +667,48 @@ gawk(const char **addr)
 
 	--depth;
 
-	if (ferror(stdin)) {
+	if (ferror(stdin) && !fatal) {
 		warn("'%s'", "/dev/stdin");
 		return fatal = -1;
 	}
 	return done - 1;
 }
 
+void
+sighandler(int sig)
+{
+	switch (sig) {
+	case SIGCHLD:
+		while (waitpid(WAIT_ANY, NULL, WNOHANG) > 0);
+		break;
+	default:
+		fclose(stdin);
+		fatal = 1;
+	}
+}
+
 int
 main(int argc, char *argv[])
 {
+	int i;
 	int status;
 
+	if (argc > 1 && *argv[1] == '-') {
+		fprintf(stderr, "usage: %s [path [host [port]]]\n", getprogname());
+		return 1;
+	}
+
 #ifdef __OpenBSD__
 	if (pledge("stdio rpath wpath cpath inet dns proc exec", NULL) == -1)
 		err(1, "pledge");
-#endif
+#endif /* __OpenBSD__ */
+
+	for (i = 0; i < LEN(signals); ++i)
+		signal(signals[i], sighandler);
 
 	if (mkdtemp(tmpdir) == NULL)
 		err(1, "mkdtemp '%s'", tmpdir);
-
 	status = sgoto(argc - 1, (const char **)argv + 1, 0, default_address);
-	if (status)
-		fprintf(stderr, "usage: %s [path [host [port]]]\n",
-		    getprogname());
-
 	if (rmdir(tmpdir) == -1)
 		err(1, "rmdir '%s'", tmpdir);