#!/bin/sh
#
# xonjointdisplau - the geometry of the largest display horiz. across screens
#
# $Id$

margin=25

Die() { echo fatal error: $@ 1>&2; exit 1; }

DieIfMissing()
{
  for x in "$@"
  do
     command -v "$x" >/dev/null || Die cannot find required executable $x
  done
}

DieIfMissing sort xdisplaygeometries

xdisplaygeometries | grep -q . || Die cannot find any screens to use

xdisplaygeometries |
perl -lnwe '
  BEGIN { my %g; };
  my ($w,$h,$r,$t) = /^(\d+)x(\d+)\+(\d+)\+(\d+)/ or next;
  $g{$r}{h} = $h;
  $g{$r}{w} = $w;
  END {
    my ($ww,$hh) = (0,0);
    for (my $r = 0; defined $g{$r}; $r += $g{$r}{w})
    {
      $ww += $g{$r}{w};
      $hh = $g{$r}{h} if ($hh == 0 || $g{$r}{h} < $hh);
    }
    printf("%dx%d+0+0\n", $ww-'$margin', $hh-'$margin')
  }'