pacundo/pacundo.pl

190 lines
4.9 KiB
Perl
Raw Normal View History

#!/usr/bin/env perl
# Copyright (C) 2024 Ortega Froysa, Nicolás <nicolas@ortegas.org> All rights reserved.
# Author: Ortega Froysa, Nicolás <nicolas@ortegas.org>
#
# This software is provided 'as-is', without any express or implied
# warranty. In no event will the authors be held liable for any damages
# arising from the use of this software.
#
# Permission is granted to anyone to use this software for any purpose,
# including commercial applications, and to alter it and redistribute it
# freely, subject to the following restrictions:
#
# 1. The origin of this software must not be misrepresented; you must not
# claim that you wrote the original software. If you use this software
# in a product, an acknowledgment in the product documentation would be
# appreciated but is not required.
#
# 2. Altered source versions must be plainly marked as such, and must not be
# misrepresented as being the original software.
#
# 3. This notice may not be removed or altered from any source
# distribution.
use strict;
use warnings;
use feature qw(signatures);
use Getopt::Std;
use File::ReadBackwards;
my $VERSION = "1.0";
my $PROG_NAME = "pacundo";
sub print_version() {
print("$PROG_NAME v$VERSION\n");
return;
}
sub print_help() {
&print_version();
print("A time machine to return your ArchLinux machine back to a working state.
USAGE:
$PROG_NAME [-i|-r] [-t <num>] [-d]
$PROG_NAME -h
$PROG_NAME -v
OPTIONS:
-i Enter interactive mode to select packages to downgrade [default behavior]
-r Automatically downgrade all packages from last upgrade
-t <num> Specify the number of transactions to include for undoing selection [default 1]
-d Dry run, i.e. don't actually do anything
-h Show this help information
-v Print program version\n");
return;
}
sub read_txs($num_txs = 1) {
my $found_txs = 0;
my $in_tx = 0;
my @undo_txs;
my $pacman_log = File::ReadBackwards->new("/var/log/pacman.log") or
die("Failed to load pacman log file.\n$!");
while ($found_txs < $num_txs && defined(my $line = $pacman_log->readline)) {
unless ($in_tx) {
# Remeber that we're reading this in reverse order
if ($line =~ /\[ALPM\] transaction completed/) {
$in_tx = 1;
}
} elsif ($line =~ /\[ALPM\] transaction started/) {
$found_txs++;
$in_tx = 0;
} elsif ($line =~ /\[ALPM\] (upgraded|downgraded)/) {
my ($action, $pkg_name, $oldver, $newver) =
$line =~ /\[ALPM\] (upgraded|downgraded) ([^\s]+) \((.*) -> (.*)\)/;
push(@undo_txs,
{
'action' => $action,
'pkg_name' => $pkg_name,
'oldver' => $oldver,
'newver' => $newver,
}
);
} elsif ($line =~ /\[ALPM\] (installed|removed)/) {
my ($action, $pkg_name) = $line =~ /\[ALPM\] (installed|removed) ([^\s]+)/;
push(@undo_txs,
{
'action' => $action,
'pkg_name' => $pkg_name,
}
);
}
}
return @undo_txs;
}
sub select_txs(@undo_txs) {
print("Last changes:\n");
my $n = 1;
foreach my $tx (@undo_txs) {
format UPGRFORMAT =
@|| @<< @<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< @<<<<<<<<<<< -> @<<<<<<<<<<<<<
$n, $tx->{action}, $tx->{pkg_name}, $tx->{oldver}, $tx->{newver}
.
format INSTFORMAT =
@|| @<< @<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
$n, $tx->{action}, $tx->{pkg_name}
.
local $~ = ($tx->{action} =~ /(upgraded|downgraded)/) ? "UPGRFORMAT" : "INSTFORMAT";
write();
$n++;
}
print("Select transactions to undo (e.g. '1 2 3', '1-3')\n");
print("> ");
my @sel = split(' ', <STDIN>);
foreach my $i (grep({/^[0-9]+-[0-9]+$/} @sel)) {
my ($start, $end) = $i =~ /^([0-9]+)-([0-9]+)$/;
die("Invalid range: $start-$end\n") if ($start >= $end);
push(@sel, ($start..$end));
}
@sel = sort grep({!/[0-9+]-[0-9+]/} @sel);
my @sel_undo;
push(@sel_undo, $undo_txs[$_-1]) foreach (@sel);
return @sel_undo;
}
sub get_pkgmgr() {
my $mgr = $ENV{DEFAULT_PKGMGR} // 'pacman';
my $mgr_bin = `which $mgr 2>&1`;
if ($? != 0) {
print(STDERR "Failed to find pacman executable. Are you using an ArchLinux system?\n");
exit 1;
}
my $mgr_cmd_search = "$mgr_bin -Ss";
my $mgr_cmd_install_remote = "$mgr_bin -S";
my $mgr_cmd_install_local = "$mgr_bin -U";
my %pkgmgr = (
name => $mgr,
bin => $mgr_bin,
search => $mgr_cmd_search,
install_remote => $mgr_cmd_install_remote,
install_local => $mgr_cmd_install_local,
);
return \%pkgmgr;
}
getopts("irt:dvh", \my %opts);
if ($opts{'v'}) {
&print_version();
exit 0;
} elsif ($opts{'h'}) {
&print_help();
exit 0;
} elsif ($opts{'r'} && $opts{'i'}) {
print("Improper usage. -r and -i cannot be used at the same time.\n");
print("Use -h for help information.\n");
exit 1;
} elsif ($opts{'t'} && !($opts{'t'} =~ /[0-9]+/)) {
print("The argument for -t must be a positive integer.\n");
exit 1;
}
my $r_flag = $opts{'r'} // 0;
my $dry_run = $opts{'d'} // 0;
my $num_txs = $opts{'t'} // 1;
my $pkgmgr = &get_pkgmgr();
my @undo_txs = &read_txs($num_txs);
# Interactive mode
@undo_txs = &select_txs(@undo_txs) unless ($r_flag);