#! /usr/bin/perl

use strict;
use warnings;

unless ( open( FILE, "name_of_file" ) ) {
    die "Could not open file for reading\n";
}

my %hash;
while (<FILE>) {
    if ($_ =~ /^(maintenance_mode)\s([\w,=]*)$/) {
	$hash{$1} = $2;
    }
}