/*
$ dcc exec.c
$ a.out
good-bye cruel world
$
*/

#include <stdio.h>
#include <unistd.h>

extern char **environ;

// simple example of program replacing itself with exec
int main(void) {
    // What is we remove newline (compile with gcc)
    printf("Hello\n");
    
    // What happens if we do not put /usr/bin/echo in here?
    char *echo_argv[] = {"/usr/bin/echo","good-bye","cruel","world",NULL};

    //What if we just have "echo"
    execve("/usr/bin/echo", echo_argv, environ);   

    printf("goodbye\n");
    // if we get here there has been an error
    perror("execve");
    return 1;
}