add killall

src/procps/kill/kill.c

@@ -3,6 +3,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <signal.h>
+#include <dirent.h>
 #include <unistd.h>
 
 typedef struct {
@@ -48,11 +49,21 @@ int parse_sig(char *arg) {
 	return SIGTERM;
 }
 
+int my_kill(pid_t pid, int signal) {
+	if (kill(pid, signal)) {
+		fprintf(stderr, "kill: %d: %s\n", pid, strerror(errno));
+		return 1;
+	}
+
+	return 0;
+}
+
 int main(int argc, char **argv) {
+	unsigned int a_flag = 0;
 	int signal = SIGTERM;
 
 	int opt;
-	while ((opt = getopt(argc, argv, "s:l")) != -1) {
+	while ((opt = getopt(argc, argv, "s:la")) != -1) {
 		switch (opt) {
 			case 'l':
 				for (size_t i = 0; i < sizeof(signals) / sizeof(signals[0]); i++)
@@ -64,8 +75,12 @@ int main(int argc, char **argv) {
 				signal = parse_sig(optarg);
 				break;
 
+			case 'a':
+				a_flag = 1;
+				break;
+
 			default:
-				printf("kill [pid1 pid2...]\n\t[-s SIG] [-l List all signals]\n");
+				printf("kill [pid1 pid2...]\n\t[-s SIG] [-l List all signals]\n\t[-a Kill all process]\n");
 				return 0;
 		}
 	}
@@ -74,12 +89,35 @@ int main(int argc, char **argv) {
 	argc -= optind;
 
 	int ret = 0;
-	for (int i = 0; i < argc; i++) {
-		int pid = atoi(argv[i]);
 
-		if (kill(pid, signal)) {
-			fprintf(stderr, "kill: %d: %s\n", pid, strerror(errno));
-			ret = 1;
+	if (a_flag) {
+		DIR *dp = opendir("/proc");
+		if (dp == NULL) {
+			fprintf(stderr, "kill: /proc: %s\n", strerror(errno));
+			return 1;
+		}
+
+		pid_t my_pid = getpid();
+
+		struct dirent *ep;
+		while ((ep = readdir(dp)) != NULL) {
+			pid_t pid = atoi(ep->d_name);
+			if (pid == 0 || pid == my_pid)
+				continue;
+
+			if (my_kill(pid, signal))
+				ret = 1;
+		}
+
+		closedir(dp);
+	}
+
+
+	else {
+		for (int i = 0; i < argc; i++) {
+			pid_t pid = atoi(argv[i]);
+			if (my_kill(pid, signal))
+				ret = 1;
 		}
 	}