checkupdate.pl

#!/usr/bin/env perl

=for comment
Copyright 2020 Niko Lepka

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation 
and/or other materials provided with the distribution.

3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software 
without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 
THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 
IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 
OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 
OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
=cut

use v5.30;
use warnings;
no warnings qw( experimental::smartmatch );
use autodie;
use POSIX;
use constant {
    DAY   => 3,
    MONTH => 4,
    YEAR  => 5,
};

my $scripts_folder = '/home/nle/scripts';
my $date_path = "$scripts_folder/files/lastupdate";

sub check_date {
    my ($old, $new) = @_;

    return $old->[YEAR]  < $new->[YEAR] 
        || $old->[MONTH] < $new->[MONTH] 
        || $old->[DAY]   < $new->[DAY];
}

sub read_date {
    open(my $handle, '<', $date_path);
    chomp(my $line = <$handle>);
    $line;
}

sub write_date {
    my ($reason, @date) = @_;
    my $str = join(',', @date, uc($reason));
    open(my $handle, '>', $date_path);
    say $handle $str;
}

my $line = read_date;

my @current_time = localtime;

my @old_time = split(',', $line);

# perform check
if (!$line || check_date(\@old_time, \@current_time)) {
    # prompt user
    if (!$line) {
        print "Last update never performed. ";
    } else {
        my $time = mktime @old_time;
        printf(
            "Last update performed on %4d-%02d-%02d. ", 
            $old_time[YEAR] + 1900, 
            $old_time[MONTH] + 1, 
            $old_time[DAY]
        );
    }

    while() {
        print "Check for updates? (y/n) ";

        chomp(my $response = <STDIN>);

        # execute command if needed
        given ($response) {
            when (m/(n|no)/i) {
                write_date 'aborted', @current_time;
                say 'Performing no updates.';
                exit;
            }
            when (m/(y|yes)/i) {
                write_date 'updated', @current_time;
                system "$scripts_folder/autoupdate";
                exit;
            }
            default {
                say "Did not understand input $response, try again";
            }
        }
    }
}