Renaming all folders

05_ProcessManagement/system.c

@@ -0,0 +1,71 @@
+/*
+ * SPDX-License-Identifier: MIT
+ * Copyright (c) 2025 Fabio Scotto di Santolo
+ */
+
+
+#include <stdio.h>
+#define _XOPEN_SOURCE
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+/* my_system - synchronously spawns and waits for the command
+ * "/bin/sh -c <cmd>".
+ *
+ * Returns -1 on error of any sort, or the exit code from the
+ * launched process. Does not block or ignore any signals.
+ */
+int my_system(const char *);
+
+int main(int argc, char *argv[])
+{
+	if (argc < 2) {
+		fprintf(stderr, "usage: %s <command>", argv[0]);
+		return EXIT_FAILURE;
+	}
+
+	const char *command = argv[1];
+	pid_t pid = fork();
+	if (pid == -1) {
+		perror("fork");
+		return EXIT_FAILURE;
+	} else if (pid > 0) {
+		int ret = my_system(command);
+		if (ret == -1) {
+			fprintf(stderr, "command: \"%s\" error", command);
+			return EXIT_FAILURE;
+		}
+		return ret;
+	}
+
+	int status;
+	wait(&status);
+	return status;
+}
+
+int my_system(const char *cmd)
+{
+	pid_t pid = fork();
+	if (pid == -1) {
+		return -1;
+	} else if (pid == 0) {
+		const char *argv[4];
+		argv[0] = "sh";
+		argv[1] = "-c";
+		argv[2] = cmd;
+		argv[3] = NULL;
+
+		execv("/bin/sh", argv);
+		exit(-1);
+	}
+
+	int status;
+	if (waitpid(pid, &status, 0) == -1) {
+		return -1;
+	} else if (WIFEXITED(status)) {
+		return WEXITSTATUS(status);
+	}
+	return -1;
+}