fork download
copy 
  1. /****************************************************************
  2.  *
  3.  *    Example: to demonstrate fork() and execl() and system calls
  4.  *
  5.  ***************************************************************/
  6. #include <stdio.h>
  7. #include <stdlib.h>
  8. #include <sys/types.h>
  9. #include <unistd.h>
  10. #include <sys/wait.h>
  11.  
  12. int main( int argc, char *argv[], char *env[] )
  13. {
  14.    pid_t my_pid, parent_pid, child_pid;
  15.    int status;
  16.  
  17. /* get and print my pid and my parent's pid. */
  18.  
  19.    my_pid = getpid();    parent_pid = getppid();
  20.    printf("\n Parent: my pid is %d\n\n", my_pid);
  21.    printf("Parent: my parent's pid is %d\n\n", parent_pid);
  22.  
  23. /* print error message if fork() fails */
  24.    if((child_pid = fork()) < 0 )
  25.    {
  26.       perror("fork failure");
  27.       exit(1);
  28.    }
  29.  
  30. /* fork() == 0 for child process */
  31.  
  32.    if(child_pid == 0)
  33.    {  printf("\nChild: I am a new-born process!\n\n");
  34.       my_pid = getpid();    parent_pid = getppid();
  35.       printf("Child: my pid is: %d\n\n", my_pid);
  36.       printf("Child: my parent's pid is: %d\n\n", parent_pid);
  37.       printf("Child: I will sleep 3 seconds and then execute - date - command \n\n");
  38.  
  39.       sleep(3); 
  40.       printf("Child: Now, I woke up and am executing date command \n\n");
  41.       //execl("/bin/date", "date", NULL);/* execl("/bin/date","date",0,0); */
  42.       execlp("date", "date",NULL); /* execlp("date","date",0,0);
  43.       perror("execl() failure!\n\n");
  44.  
  45.       printf("This print is after execl() and should not have been executed if execl were successful! \n\n");
  46.  
  47.       _exit(1);*/
  48.    }
  49. /*
  50.  * parent process
  51.  */
  52.    else
  53.    {
  54.       printf("\nParent: I created a child process.\n\n");
  55.       printf("Parent: my child's pid is: %d\n\n", child_pid);
  56.       system("ps -el | grep wait");  printf("\n \n");
  57.       wait(&status); /* can use wait(NULL) since exit status
  58.                         from child is not used. */
  59.       printf("\n Parent: my child is dead. I am going to leave.\n \n ");
  60.    }
  61.  
  62.    return 0;
  63. }
  64. /*
  65.  *  Parent: my pid is 2020
  66.  *
  67.  *  Parent: my parent's pid is 1740
  68.  *
  69.  *
  70.  *  Parent: I created a child process.
  71.  *
  72.  *  Parent: my child's pid is: 2021
  73.  *
  74.  *
  75.  *  Child: I am a new-born process!
  76.  *
  77.  *  Child: my pid is: 2021
  78.  *
  79.  *  Child: my parent's pid is: 2020
  80.  *
  81.  *  Child: I will sleep 3 seconds and then execute - date - command 
  82.  *
  83.  *  1 S     0   996     1  0  80   0 - 29038 wait   ?        00:00:00 ksmtuned
  84.  *  0 S   500  1740  1734  0  80   0 - 29105 wait   pts/0    00:00:00 bash
  85.  *  0 S   500  2020  1740  0  80   0 -   998 wait   pts/0    00:00:00 a.out
  86.  *  0 S   500  2022  2020  0  80   0 - 28512 wait   pts/0    00:00:00 sh
  87.  *
  88.  *   
  89.  *   Child: Now, I woke up and am executing date command 
  90.  *
  91.  *   Tue Aug 27 09:07:37 IST 2013
  92.  *
  93.  *    Parent: my child is dead. I am going to leave.
  94.  */
  95.  
  96.  
Success #stdin #stdout 0.02s 5284KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
Wed 11 Sep 2024 04:46:28 PM UTC

 Parent: my pid is 358759

Parent: my parent's pid is 358758


Parent: I created a child process.

Parent: my child's pid is: 358762


 

 Parent: my child is dead. I am going to leave.
https://ideone.com/dcdxlB
language:
C (gcc 8.3)
created:
8 days ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!