View difference between Paste ID: LK59pJzC and FLBqcyHt

 #include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
 #define READ_END 0
 #define WRITE_END 1
 
 
 int
 main() {
 
   pid_t c1_pid = fork();
   int c1_status = 0;
 
   int pipefd[2];
 
   if (pipe(pipefd) == -1) {
       perror("pipe");
       exit(EXIT_FAILURE);
   }
 
 
-    // child
+
     perror("fork");
     exit(EXIT_FAILURE);
   } else if (c1_pid == 0) {
-    dup2(pipefd[1], STDOUT_FILENO);
+    // child 1
-    close(pipefd[1]);
+
-    close(pipefd[0]);
+
 
     dup2(pipefd[WRITE_END], STDOUT_FILENO);
     close(pipefd[WRITE_END]);
     close(pipefd[READ_END]);
 
     printf("hello world\n");
 
   } else {
     // parent
 
     pid_t c2_pid = fork();
     int c2_status = 0;
 
     if (c2_pid < 0) {
       perror("fork");
       exit(EXIT_FAILURE);
-      dup2(pipefd[0], STDIN_FILENO);
+
-      close(pipefd[1]);
+      // child 2
-      close(pipefd[0]);
+
       printf("second child\n");
 
       dup2(pipefd[READ_END], STDIN_FILENO);
       close(pipefd[WRITE_END]);
       close(pipefd[READ_END]);
 
       char* myargs[2];
       myargs[0] = strdup("/bin/cat");
       myargs[1] = NULL;
 
       execvp(myargs[0], myargs);
 
     } else {
       // parent
 
       pid_t finished_c2_pid = waitpid(c2_pid, &c2_status, WUNTRACED);
       printf("finished c2 process: %d\n", finished_c2_pid);
     }
 
     close(pipefd[WRITE_END]);
     close(pipefd[READ_END]);
 
     pid_t finished_c1_pid = waitpid(c1_pid, &c1_status, WUNTRACED);
     printf("finished c1 process: %d\n", finished_c1_pid);
   }
 
   return 0;
 }