execv()

/* Exec/execlv.c */
#include <stdio.h>
#include <unistd.h>
int main(int argc,char *argv[]){ 
    char *arg[] = {"ls","-l",NULL}; 
    printf("Using *execv* to exec ls -l...\n");
    execv("/bin/ls",arg); 
    printf("Program Terminated\n"); 
    return 0;
}

execv() uses pathname, argument array and original ENV to execute the program.

execv("/bin/ls",arg);

You need to specify the absolute path for your target program and array of char* for the program arguments.

Lastly execv() uses original system enviroment variables for the new program.