fork download 
  1. #include <stdio.h>
  2. #include <unistd.h>
  3.  
  4. int main(int argc, char **argv) {
  5.     int send[2];
  6.     if(pipe(send)!=0) {
  7.         perror("pipe");
  8.     } else {
  9.         int pid = fork();
  10.         if(pid < 0) {
  11.             perror("fork");
  12.         }
  13.         else if(pid>0) {
  14.             //Parent process
  15.             close(send[0]);  // close pipe input 
  16.             dup2(send[1], 1); // replace stdout with pipe output
  17.  
  18.             // send message to child
  19.             fprintf(stdout, "send to child\n");
  20.             fflush(stdout);
  21.         }  else {
  22.             //Child process                     
  23.             close(send[1]);      // close pipe output                       
  24.             dup2(send[0], 0); // replace stdin with pipe input
  25.  
  26.             char message[2048];
  27.             if(fgets(message, 2048, stdin) != NULL) {
  28.                 fprintf(stdout, "message from parent:%s", message);
  29.             }
  30.         }
  31.     }
  32. }
Success #stdin #stdout 0s 4536KB
comments (?)
stdin 
Standard input is empty
stdout 
message from parent:send to child
https://ideone.com/A77XXG
https://stackoverflow.com/questions/49093873/communicating-between-a-child-process-and-a-parent-process/49096588#49096588
language:
C (gcc 8.3)
created:
7 years 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!