Add example of a child executing another program

Author: coditva

fork_this_shit/Makefile

@@ -1,6 +1,6 @@
 
 # Add all targets here
-BINARIES=simple_fork child_status
+BINARIES=simple_fork child_status child_exec
 
 all: $(BINARIES)
 
@@ -17,6 +17,12 @@ child_status.o: child_status.c
 	gcc child_status.c -c
 
 
+child_exec: child_exec.o
+	gcc -o child_exec child_exec.o
+child_exec.o: child_exec.c
+	gcc child_exec.c -c
+
+
 .PHONY: clean
 clean:
 	rm -f *.o $(BINARIES)

fork_this_shit/child_exec.c

@@ -0,0 +1,27 @@
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+int main(int argc, char *argv[])
+{
+    pid_t pid;
+    pid = fork();
+
+    if (pid < 0) {
+        /* there was an error */
+        fprintf(stderr, "%d: Fork failed\n", getpid());
+    } else if (pid == 0) {
+        /* child gets a pid of zero */
+        printf("Child:\n");
+        execl("/bin/ls", "ls", NULL);
+        printf("We'll never reach here\n");
+    } else {
+        /* inside parent */
+        wait(NULL);
+        printf("\nChild complete\n");
+    }
+
+    return 0;
+}