wait

wait

• Waits for a child process to terminate and returns the pid of the deceased process, or -1 if there are no child processes. The status is returned in $?. If you get zombie child processes, you should be calling either this function or waitpid. A common strategy to avoid such zombies is:
  
  

  $SIG{CHLD} = sub {
   wait };
  

  
  
  If you expected a child and didn't find it, you probably had a call to system, a close on a pipe, or backticks between the fork and the wait. These constructs also do a wait(2) and may have harvested your child process. Use waitpid to avoid this problem.