c - About vfork() system call? -
#include <stdio.h> #include<unistd.h> #include<sys/types.h> #include<sys/wait.h> #include<stdio.h> #include<stdlib.h> int main() { pid_t child_pid = vfork(); if(child_pid < 0) { printf("vfork() error\n"); exit(-1); } if(child_pid != 0) { printf("hey parent %d\nmy child %d\n",getpid(),child_pid); wait(null); } else { printf("hey child %d\nmy parent %d\n",getpid(),getppid()); execl("/bin/echo","echo","hello",null); exit(0); } return 0; } output: hey child 4 parent 3 hey parent 3 child 4 hello my question : why "hello" printed after execution of parent process? have started learning vfork(). please me this? after parent process executed, goes wait(null); blocks parent process until child process calls execl() or exit . therefore child process when parent blocked calling
