Script started on Wed Dec  3 18:23:32 2025
macbook:unix_ch13> gcc fork_and_exec_v2.c 
macbook:unix_ch13> cat fork_and_exec_v2.c 
// See the 
// Unix book by Glass and Ables, page 478
// -MCW
#include <stdio.h>
#include <stdlib.h>  // exit()
#include <unistd.h>  // fork()
#include <unistd.h>    // for fork, sleep
#include <sys/wait.h>  // for wait

int main () {
  int pid, status;
  pid = fork (); /* Duplicate */
  printf ("I'm process %d \n", getpid ());
  int childPid = 0;
  /* Branch based on return value from fork () */
  if (pid != 0)  {
    /* Wait for a child to terminate. */
    printf("As parent, I will wait for the child\n");
    childPid = wait (&status);
  }
  else {
    printf("As child, I will call echo\n");
    // NULL indicates last command. There could be more than 1
    execl ("/bin/echo", "echo", "hello", "there", NULL); /* Execute ls */
  }

  printf("The parent is ending\n");
  return 0;
}
macbook:unix_ch13> ./a.out
I'm process 14408 
As parent, I will wait for the child
I'm process 14409 
As child, I will call echo
hello there
The parent is ending
macbook:unix_ch13> cp fork_and_exec_v2.c fork_and_exec_v3.c
macbook:unix_ch13> vi fork_and_exec_v3.c 
macbook:unix_ch13> cat process2_v2.c 
// This function is from Glass and Ables' Unix book
// See monitor.c (starting on p 453)

#include <stdio.h>         /* For printf, fprintf */
#include <stdlib.h>  // exit()
#include <string.h>        /* For strcmp */
#include <ctype.h>         /* For isdigit */
#include <fcntl.h>         /* For O_RDONLY */
#include <dirent.h>        /* For getdents */
#include <sys/stat.h>      /* For IS macros */
#include <sys/types.h>     /* For modet */
#include <time.h>      /* For localtime, asctime */


void processDirectory (char* dirName) {

/* Process all files in the named directory */

  DIR *dp;

  struct dirent *dep;

  //char fileName [MAX_FILENAME];

  dp = opendir (dirName); /* Open for reading */
  if (dp == NULL) {
    perror("monitor: ");
    exit(1);
  }

  while ((dep = readdir(dp))) /* Read all dir entries */ {
    if (strcmp (dep->d_name, ".") != 0&&
        strcmp (dep->d_name, "..") != 0) /* Skip . .. */ {
      printf ("%s/%s \n", dirName, dep->d_name); // was sprintf
      //monitorFile (fileName);  /* Call recursively */
    }
  }

  closedir (dp); /* Close directory */

}

int main() {
  processDirectory(".");
  return 0;
}

macbook:unix_ch13> gcc process2_v2.c -o process2_v2
macbook:unix_ch13> vi fork_and_exec_v3.c           
macbook:unix_ch13> gcc fork_and_exec_v3.c -o fork_and_exec_v3
macbook:unix_ch13> ./fork_and_exec_v3 
I'm process 14513 
As parent, I will wait for the child
I'm process 14514 
As child, I will call process2_v2 
./myfork.c 
./monitor_original.c 
./pgrp2.c 
./myexec.c 
./myfork2.c 
./monitor.c 
./pipe_fork_signal_wait.c 
./Dec3_2025.log 
./fork_and_exec_v2.c 
./unnamed_pipes_figure.txt 
./process2.c 
./processDirectory.c 
./exec_man_page.html 
./nonexist.txt 
./seek_example.c 
./mychdir.c 
./sparse.c 
./pgrp1.c 
./sparse.txt 
./fork_and_exec.c 
./myexit.c 
./lstat_example.c 
./mydup.c 
./fork_example2.c 
./zombie.c 
./talk.c 
./myfork4.c 
./reverse_ch13_KandR.c 
./a.out 
./process2_v2.c 
./reverse_unix_ch13.c 
./pipe_example.c 
./mydup_w_comments.c 
./pipe_example_3.c 
./test.txt 
./pipe_example_v2.c 
./fork_example.c 
./orphan.c 
./processDirectory_v2.c 
./process2_v2 
./myfork3.c 
./wait.c 
./reverse_unix_ch13_original.c 
./fork_and_exec_v3.c 
./mywait.c 
./fileIOerror.c 
./fork_and_exec_v3 
./talk 
./normal.txt 
The parent is ending
macbook:unix_ch13> cat fork_and_exec_v3.c 
// See the 
// Unix book by Glass and Ables, page 478
// -MCW
#include <stdio.h>
#include <stdlib.h>  // exit()
#include <unistd.h>  // fork()
#include <unistd.h>    // for fork, sleep
#include <sys/wait.h>  // for wait

int main () {
  int pid, status;
  pid = fork (); /* Duplicate */
  printf ("I'm process %d \n", getpid ());
  int childPid = 0;
  /* Branch based on return value from fork () */
  if (pid != 0)  {
    /* Wait for a child to terminate. */
    printf("As parent, I will wait for the child\n");
    childPid = wait (&status);
  }
  else {
    printf("As child, I will call process2_v2 \n");
    // NULL indicates last command. There could be more than 1
    execl ("./process2_v2", "process2_v2", NULL); /* Execute ls */
  }

  printf("The parent is ending\n");
  return 0;
}
macbook:unix_ch13> exit

Saving session...
...copying shared history...
...saving history...truncating history files...
...completed.
Deleting expired sessions...       9 completed.

Script done on Wed Dec  3 18:50:33 2025