#!/usr/bin/perl

use Fcntl;
use strict;
use vars qw(@sig $sig $lidx);

my $FIFO = '.sig-dyn';
#$SIG{PIPE} = sub { warn("Broken pipe: $!\n") };
$SIG{PIPE} = 'IGNORE';
$SIG{HUP} = \&readsigs;
$SIG{TERM} = sub { exit(0) };

sub readsigs ()
{
    chdir;
    if(sysopen(SIGS, join('/',$ENV{HOME}, qw(sigd sigfile)), O_RDONLY, undef))
    {
	$/ = "--\n";
	chomp(@sig = <SIGS>);
	close(SIGS);
	$sig =
	  sub
	  {
	      my $idx;
	      for($idx = $lidx; $idx == $lidx; $idx = int(rand(@sig))) {}
	      join('', "-- \n", $sig[$lidx = $idx]);
	  };
    }
    else { $sig = sub { "-- \n".`fortune -s` } }

    unless(-p $FIFO)
    {
	rename($FIFO, "$FIFO~");	
	system(mkfifo => $FIFO)
	  && system(mknod => $FIFO, 'p')
	    && die("mk{nod|fifo} failed: $!\n");
    }
}

readsigs();

fork() && exit(0);

SIGLOOP:
{
    my $wi = '';
    my $wo = '';

    while (-p $FIFO)
    {
	my $s = $sig->();
	my $l = length($s);
	sysopen(FIFO, $FIFO, O_WRONLY|O_SYNC, undef)
          || die("sysopen(FH, $FIFO, O_WRONLY|O_SYNC, undef) failed: $!\n");
        syswrite(FIFO, $s, $l, 0);
        close(FIFO);
        select(undef(), undef(), undef(), 0.5);
    }
}

warn("$FIFO is not a pipe: exiting\n");
exit(0);