I'm guessing that the Perl script's STDOUT and STDERR are getting closed, sending a SIGPIPE to the email server, making it think the child exited. I don't know why it doesn't occur for the first snippet.

It could be prevented by replacing exec with system if I'm right about the cause. Don't forget to make the call to die conditional or remove it for testing.

A better system would expand on the third snippet to filter out the expected message while letting anything else through. Turns out it's pretty simple since we don't have to deal with the child's STDOUT, just its STDERR. 

#!/usr/bin/perl

use strict;
use warnings;

use IPC::Open3 qw( open3 );
use Symbol qw( gensym );

my $pid = open3(
   \*STDIN,
   \*STDOUT,
   my $fr_chld_err = gensym(),
   './home/bevs/bin/email'
);

while (<$fr_chld_err>) {
   next if /Module 'eAccelerator' already loaded/;
   print STDERR $_;
}

waitpid($pid, 0)
   or die;

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In reply to Re^3: Silencing errors in a php script using perl nd pipes. by ikegami
in thread Silencing errors in a php script using perl nd pipes. by Thorney

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