void op_dir(char * sfile, int op) {        //SEARCH "sfile" in the current directory or list the contens of the given directory
DIR* dir_point;                    //point to the current directory
struct dirent* enter;                //point to one directory entry
struct stat f_details;                 //used by lstat()
char cwdir[MAX_DIR_PATH];


//get the current working directory
  if (!getcwd(cwdir, MAX_DIR_PATH+1)) {
    perror("getcwd:");
    return;
    }

// open the directory for reading
if ((dir_point=opendir("."))==NULL){

printf("error trying to open file \n" );

}else{
// scan the directory, traversing each sub-directory, and
              
while ((enter=readdir(dir_point)))
{
if (op==1){
//display all the files and directories in the current directory
printf("%s/%s\n", cwdir, enter->d_name);
continue;
}
//matching the pattern for each file name.    
if (enter->d_name && strstr(enter->d_name, sfile)) {
        printf("%s/%s\n", cwdir, enter->d_name);
        }
// check if the given entry is a directory.
if (lstat(enter->d_name, &f_details)!=-1){

if ((strcmp(enter->d_name,".")==0 ||  strcmp(enter->d_name, "..") == 0) &&  S_ISDIR(f_details.st_mode)) {



if (chdir(enter->d_name)!= -1){



op_dir(enter->d_name,op);


}


     }
      }
         }
       }
       }

}


int emp_stack(pile **p){
    
    if((*p)->pt_prev==NULL) return 0;
    else return 1;
}
    
int  push(pile **pt_t, char *data){             //passing like arguments pointer to pointer to get the address memory of the structure
            if(pt_t !=NULL){
    pile *p_p=*pt_t;
    pile *element=NULL;

             element=malloc( sizeof( pile));  //allow the memory for the new element
            if (element !=NULL){                     //verifing if the list its empty
            //if not epmty
                          element->pt_prev=*pt_t; //point the pt_prev to the previeus element        
                      strcpy(element->data,data);     //assign the data to the data field of our structure
                              
                              *pt_t=element;
                  return 0;          //point to the top of the stack
                              }else{
                        return 1;
                                    exit(1);  
                                    
                                    }
                                    }
                                    }
      
char  *pop(pile  **p){
       char  *val=NULL;
     if(p!=NULL &&  *p!=NULL){
    pile *p_l=*p;//assignement the the last objet to the p_ls pointer
       pile *p_p=p_l->pt_prev; //saving the previeus objet
            
if (p_l!=NULL){
    
    val=p_l->data;

    free(p_l);
    p_l=NULL;
      *p=p_p;
       return val;
       }
}