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  1. #include <stdio.h>
  2. #include <unistd.h>     // for fork(), execlp(), getpid()
  3. #include <sys/types.h>  // for pid_t
  4. #include <sys/wait.h>   // for wait()
  5. #include <stdlib.h>     // for exit()
  6.  
  7. #define MAX_COUNT 5
  8.  
  9. // Function declarations
  10. void parentProcess();
  11. void childProcess();
  12.  
  13. int main()
  14. {
  15.     pid_t pid;
  16.  
  17.     // Create child process
  18.     pid = fork();
  19.  
  20.     // If fork fails
  21.     if (pid < 0)
  22.     {
  23.         printf("Fork failed\n");
  24.         return 1;
  25.     }
  26.  
  27.     // Child process
  28.     if (pid == 0)
  29.     {
  30.         childProcess();
  31.     }
  32.     // Parent process
  33.     else
  34.     {
  35.         parentProcess();
  36.     }
  37.  
  38.     return 0;
  39. }
  40.  
  41. // Child Process Function
  42. void childProcess()
  43. {
  44.     printf("Output of execlp system call:\n");
  45.  
  46.     // Executes 'ls' command
  47.     execlp("/bin/ls", "ls", NULL);
  48.  
  49.     // This line runs only if execlp fails
  50.     printf("execlp failed\n");
  51. }
  52.  
  53. // Parent Process Function
  54. void parentProcess()
  55. {
  56.     int i;
  57.     pid_t processID;
  58.  
  59.     // Wait for child process to complete
  60.     wait(NULL);
  61.  
  62.     // Get parent process ID
  63.     processID = getpid();
  64.  
  65.     // Print lines from parent
  66.     for (i = 1; i <= MAX_COUNT; i++)
  67.     {
  68.         printf("Line from parent process = %d\n", i);
  69.     }
  70.  
  71.     printf("Parent process is done\n");
  72.     printf("Parent Process ID = %d\n", processID);
  73.  
  74.     exit(0);
  75. }
Success #stdin #stdout 0s 5316KB
comments (?)
stdin
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Standard input is empty
stdout
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prog
Line from parent process = 1
Line from parent process = 2
Line from parent process = 3
Line from parent process = 4
Line from parent process = 5
Parent process is done
Parent Process ID = 3210922
https://ideone.com/sLDZhG
language:
C (gcc 8.3)
created:
9 hours ago
visibility:
public

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