How to restart a server based on a recieving a hup. The short answer is 
$SIG{HUP} = sub { exec($0, @ARGV); };

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But doing an exec() in the signal handler didn't work after the first try for me. Here's a solution that is more careful and appropriate. 
#!/usr/local/bin/perl
use strict;
use vars qw($hup);

$| = 1;
$hup = 0;

$SIG{HUP} = sub { $hup++; };   # handle the hup when convenient

print "\n$0: args @ARGV, pid $$...\n";
while (1) {
  print "grinding away...\n";
  sleep(5);
  if ($hup > 0) { exec($0, @ARGV) || warn "$!"; }
}

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In reply to catch hup, restart by thayer

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