Example for chapter on UNIX signals

chp10/multihandler.c

@@ -0,0 +1,53 @@
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+/* handler for SIGINT and SIGTERM */
+static void signal_handler(int signo)
+{
+	if (signo == SIGINT)
+		printf("Caught SIGINT!\n");
+	else if (signo == SIGTERM)
+		printf("Caught SIGTERM!\n");
+	else {
+		/* this should never happen */
+		fprintf(stderr, "Unexpected signal!\n");
+		exit(EXIT_FAILURE);
+	}
+	exit(EXIT_SUCCESS);
+}
+
+int main(void)
+{
+	/*
+	 * Register signal_handler as our signal handler
+	 * for SIGINT.
+	 */
+	if (signal(SIGINT, signal_handler) == SIG_ERR) {
+		fprintf(stderr, "Cannot handle SIGINT!\n");
+		exit(EXIT_FAILURE);
+	}
+	/*
+	 * Register signal_handler as our signal handler
+	 * for SIGTERM.
+	 */
+	if (signal(SIGTERM, signal_handler) == SIG_ERR) {
+		fprintf(stderr, "Cannot handle SIGTERM!\n");
+		exit(EXIT_FAILURE);
+	}
+	/* Reset SIGPROF's behavior to the default. */
+	if (signal(SIGPROF, SIG_DFL) == SIG_ERR) {
+		fprintf(stderr, "Cannot reset SIGPROF!\n");
+		exit(EXIT_FAILURE);
+	}
+	/* Ignore SIGHUP. */
+	if (signal(SIGHUP, SIG_IGN) == SIG_ERR) {
+		fprintf(stderr, "Cannot ignore SIGHUP!\n");
+		exit(EXIT_FAILURE);
+	}
+	printf("Hi, I'm a process with PID %d\n", getpid());
+	for (;;)
+		pause();
+	return 0;
+}