Hello! I am trying to write a script which reads from STDOUT of a worker program with timeout so that if the worker takes too long, the script can kill it and retry. However, for some reasons, the ALRM signal does not seem to be caught. I have dug up perlfunc and google, and literally copy-and-paste the eval block, which still does not work. Here is the code: 
        sub process_scheme{
          my ($output_file) = @_;
          open (OUTPUT_FILE, ">", $output_file) || die "cannot open lo
+g file";
          my $scheme_pid = open (WORKER, "worker_program < $input |") 
               || die "cannot pipe worker";
          my $str;
          while (1) {
              if (eof(WORKER)){    
                  close WORKER;
                  close OUTPUT;
                  return 1;
              }

              eval{
                  local $SIG{ALRM} = sub { die "alarm\n" }; # NB: \n r
+equired
                  alarm 1;
                  $str = <WORKER>;
                  alarm 0; # if this line is removed, the signal is ca
+ught, but outside of eval, so it halts the script
              };
              if ($@) {
                  close OUTPUT_FILE;
                  close WORKER;
                  return 0;
              }

              # process the line
              #  some code ...
              # print the line to log
              print OUTPUT_FILE $str;
          }
      }

[download]
Can some monks please help me? Thank you!

In reply to Cannot catch ALRM signal for timeout by Magice

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