int main () {   pid_t pid;                      int status;                      pid = fork ();   printf ("se executa ..\n");    if (pid < 0)     {       perror ("eroare la fork");       exit (1);     }   else if (pid)                     { if (wait (&status) < 0)         {           perror ("wait()");         }       printf ("Comanda a fost executata.\n");       exit (0);     }   else                               {       execlp ("ls",               /* comanda de executat (se va cauta in direc$               "ls",                            "-a",                            "-l",                            NULL);       printf ("Eroare de executie!\n");       exit (1);  } }  pt comanda ls ar fi bun codu asta ..de rulat ruleaza si imi afiseaza fisierele