c - combine fork execl wait -

i have create prog1 take 1 argument number of children have create. (example "./prog1 5" - create 5 children) each of children generate random number 1 20. number given execl start prog2 (in same folder) take argument random number. prog2 should sleep random number time. after should return random number parent.
created still don't work properly.

prog1:

#include <stdio.h> #include <sys/types.h> #include <unistd.h> #include <stdlib.h> #include <sys/wait.h>  int main(int argc, char *argv[]) {     int n, i, pid;     int u = getppid();     int procesy = 0;      pid_t proc_id;      n = atoi(argv[1]);      for(i = 0; < n; i++)     {         proc_id = fork();          if(proc_id==0)         {             srand(getpid());             u = 1 + rand()%20;             execl("./prog2", "prog2", u,0);          }         else         {             procesy++;         }     }      if(u == getppid())     {         for(i = 0; < n; i++)         {             pid = wait(&u);             printf("process %d ende\n", pid);             procesy--;         }          if(procesy == 0) printf("endc\n");     }     return 1; } 

prog2:

    #include <stdio.h>     #include <sys/types.h>     #include <unistd.h>     #include <stdlib.h>     #include <sys/wait.h>      int main(int argc, char *argv[])     {       int n;       n = atoi(argv[1]);       sleep(n);        exit(n);     } 

change loop following, in order call execl():

if(proc_id==0) {     char arg[16];     srand(getpid());     sprintf(arg, "%d", 1 + rand()%20);     execl("./prog2", "prog2", arg, 0);     printf("i should not here!\n");     exit(-1); } 

then rid of if(u == getppid()) (but keep contents of conditional). seems if trying filter out child running block. when execl() works, child not going run anything in code after execl()... printf , exit added not run. lines run if execl() fails, , in simple case, way fail if you've provided improper arguments.