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


int sum;
int main (int argc, char* argv[]){
 
int ch;


while(1){printf("write a commmand:  ");
ch = getchar();
if(fork()==0)

if(ch=='l'){execlp("ls","ls","-l", NULL);}
else{execlp("uptime","uptime", NULL);}
wait3(&ch, 0, NULL);
}



};