add system

libc/system.c

@@ -0,0 +1,21 @@
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+
+int system(const char * command) {
+	char * args[] = {
+		"/bin/sh",
+		"-c",
+		(char *)command,
+		NULL,
+	};
+	pid_t pid = fork();
+	if (!pid) {
+		execvp(args[0], args);
+		exit(1);
+	} else {
+		int status;
+		waitpid(pid, &status, 0);
+		return status;
+	}
+}