#!/usr/bin/perl

use strict;
use warnings;

my $ldif  = "file.ldif.bz2";
my $match = "g2ucab";

$/ = "";

open my $fh, "-|", "/usr/bin/bzcat $ldif"
   or die "open error ($ldif): $!";

while ( <$fh> ) {
    if ( /uid=$match/m ) {
        print $_;
        last;
    }
}

close $fh;