ls

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

int main()
{
pid_t pid;
int status;
char *argv[ ] ={"ls","-al","/etc/passwd",0};
if((pid = fork()) == 0)
{
if(execvp("ls",argv)< 0)
{
printf("Command not found.\n");
exit(0);
}
}
else
{
waitpid(pid, &status, 0 );
}
}