#!/usr/bin/perl 
use strict;
use warnings;
use Fcntl qw( :seek );

my $rx = qr/c9391b56-b174-441b-921c-7d63/;
my $to_print = 0;
my $context = 10;
my @offs = ( 0 ) x ( 1 + $context );

while(<>) {
    my $context_start = shift @offs;
    my $here = tell ARGV;
    push @offs, $here;
    if( /$rx/ ) {
        if( not $to_print ) {
            my $length = $here - $context_start;
            seek ARGV, $context_start, SEEK_SET;
            read ARGV, $_, $length;
        }
        $to_print = 1 + $context;
    }
    --$to_print, print if $to_print;
}