add fork and comment translate

CMakeLists.txt

@@ -8,3 +8,4 @@ include_directories(${PROJECT_SOURCE_DIR})
 add_executable( hello                     src/hello.c                   )
 add_executable( args                      src/args.c                    )
 add_executable( translate                 src/translate.c               )
+add_executable( fork                      src/fork.c                    )

src/fork.c

@@ -0,0 +1,21 @@
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+int main(int argc, char *argv[]) {
+  pid_t pid;
+  if ((pid = fork()) < 0) {
+    fprintf(stderr, "ERROR: Fork failed (%s)\n", strerror(errno));
+    return 1;
+  }
+
+  if (pid != 0) {
+    printf("Parent process (%d) of child process (%d)\n", getpid(), pid);
+  } else {
+    printf("Child process (%d)\n", getpid());
+  }
+
+  return 0;
+}

src/translate.c

@@ -1,3 +1,7 @@
+/*
+* Read from stdin. replace all occurences of arg 1 with arg2.
+*/
+
 #include <stdio.h>
 int main(int argc, char *argv[])
 {