Question

I’m playing with execvp(), and found a interesting thing, here is the code first of all.
using namespace std;

#include <iostream>
#include <unistd.h>

int main(){

    char *argv[3];
    int pid = fork();
    if (pid == 0){
    argv[0] = "ls";
    argv[1] = "-l";
    argv[2] = NULL;
    execvp("ls", argv);
    }

}

This is a simple fork + execvp problem, but I found that after “ls” was executed successfully, I will have to hit Enter to come back to command line (shell).

Anyone know how do I make it so that after execvp(“ls”) I can go back to shell without hit my “Enter”?

Answer 1

Your main program exits before the ls completes. By the time ls completes, its output has obscured the shell prompt.

You can solve this with either of these:

• Add else wait(0); after the if‘s closing brace.
• Delete the call to fork().