From the variation on a theme department

spawn("./ntlogin.sh",undef,"data.out");

exit(0);
#
# spawn($cmd[,$env_vars,[,$stdout_log[,$stderr_log]]])
# $cmd = the command to execute
# $env_vars = anonymous hash containing special environmenal
#             values (eg VAR => VALUE)
# $stdout_log = a path to a log file for stdout
# $stderr_log = a path to a log file for stderr

sub spawn {
  my ($cmd_to_exec,$env_vars,$stdout_log,$stderr_log)=@_;

  my $pid=fork(); #Fork off!

  if ($pid > 0 ) { # This is the parent process
    return $pid;
  } elsif ( $pid == 0 ) { 
    # this is the child
    if ($env_vars) {
      #
      # We have special environmental vars to pass
      foreach my $key(keys %$env_vars) {
    $ENV{$key}=$env_vars->{$key};
      }
    }
    #
    # Next we want to close STDOUT and STDERR 
    close STDOUT;
    close STDERR;
    #
    # Check to see if we have a filename passed 
    if ($stdout_log) {
      #
      # If there is no stderr_log
      if (! $stderr_log) {
    $stderr_log=">&STDOUT";
      } else {
    $stderr_log="> " . $stderr_log;
      }
      $stdout_log="> $stdout_log";
      open STDOUT,$stdout_log or die "$stdout_log:$!";
      open STDERR,$stderr_log or die "$stderr_log:$!";
    }
    #
    # Finally we exec the command
    exec $cmd_to_exec or die "$cmd_to_exec: $!";
  } else {
    die "Could not fork! :$!";
  }
}

[download]

That's code hot off pressses. That's a sniglet from some code I wrote for an startup script to replace some crippleware one of our vendors supplied with their product.

Peter L. BergholdBrewer of Belgian Ales
Peter@Berghold.Netwww.berghold.net
Unix Professional

In reply to Re: execution of cmmand inside a program by blue_cowdawg
in thread execution of cmmand inside a program by Anonymous Monk

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