Makefile: simplify install command.

No longer exists.

.gitignore

@@ -0,0 +1 @@
+pacundo.1.gz

LICENSE

@@ -1,4 +1,4 @@
-Copyright (C) [year] Nicolás A. Ortega Froysa <nicolas@ortegas.org>
+Copyright (C) 2024 Nicolás A. Ortega Froysa <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

Makefile

@@ -0,0 +1,43 @@
+# 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.
+
+ifeq ($(PREFIX),)
+	PREFIX := /usr/local
+endif
+
+pacundo.1.gz: pacundo.1
+	gzip -c $^ > $@
+
+.PHONY: clean doc install uninstall
+
+clean:
+	$(RM) pacundo.1.gz
+
+doc: pacundo.1.gz
+
+install: pacundo.1.gz
+	install -Dm755 pacundo.pl $(PREFIX)/bin/pacundo
+	install -Dm644 pacundo.1.gz $(PREFIX)/share/man/man1/
+
+uninstall:
+	$(RM) $(PREFIX)/bin/pacundo
+	$(RM) $(PREFIX)/share/man/man1/pacundo.1.gz

README.md

@@ -7,10 +7,67 @@ to boot from a USB depending on just how broken it is).
 
 ## Installation
 
-Dependencies:
+### Dependencies
 
 - Perl 5
 - `File::ReadBackwards` module
+- cURL
+- GNU Make
+
+You can install these packages with the following command:
+
+```console
+# pacman -S perl perl-file-readbackwards curl
+```
+
+### Compiling & Installing
+
+The script is compiled and installed using GNU Makefile. Therefore you can use
+`make install` to build and install the script and its man-page as expected.
+They are installed (by default) to `/usr/local`. To change this to a different
+directory simply prepend the `PREFIX=<path>` to your `make install` command.
+
+## Usage
+
+The first concept to understand is that of a transaction. A transaction is
+defined in the pacman logs as package operations done during a single use of the
+command (or so it seems, at least). If you look at the logs
+(`/var/log/pacman.log`) this would be everything between the lines `[ALPM]
+transaction started` and `[ALPM] transaction completed`. You can set how many
+transactions to list/undo by using the `-t` argument.
+
+There are two modes for undoing pacman transactions:
+
+- Interactive (`-i`, default): will show you a numbered list with all the package
+  operations of the selected transactions.
+- Automatic (`-r`): will automatically undo all package operations of the
+  selected transactions.
+
+Look at the man-page (`man pacundo`) for more information.
+
+### Supported AUR Helpers
+
+- [yay](https://github.com/Jguer/yay)
+
+## Contributing
+
+If you find any issues, feel free to report them on GitHub or send me an E-Mail
+(see my website/profile for the address). I will add these issues to my personal
+Gitea page and (unless specified otherwise) mention you as the person who found
+the issue.
+
+For patches/pull requests, if you open a PR on GitHub I will likely not merge
+directly but instead apply the patches locally (via Git patches, conserving
+authorship), push them to my Gitea repository, which will finally be mirrored to
+GitHub. However, you can save me a bit of work by just sending me the Git
+patches directly (via E-Mail).
+
+If you're looking for a way to contribute, there are a few to-do items within
+the code which you can find using `grep`:
+
+```console
+# grep -n "TODO" pacundo.pl
+```
 
 ## License
 

pacundo.1

@@ -0,0 +1,49 @@
+.TH PACUNDO "1" "April 2024" "pacundo 1.1.1" "User Commands"
+.SH "NAME"
+pacundo - A time machine to roll back your ArchLinux machine to a working state.
+.SH "SYNOPSIS"
+.B pacundo
+[\fI\-i\fR|\fI\-r\fR] [\fI\-t\fR <\fInum\fR>] [\fI\-d\fR]
+
+.B pacundo
+\fI\-h\fR
+
+.B pacundo
+\fI\-v\fR
+
+.SH "DESCRIPTION"
+This program helps to undo the last pacman/yay transactions automatically, which
+is especially helpful if the last update broke your system for some reason.
+
+\fBNote:\fR the term \fItransaction\fR refers to an operation done by pacman
+(e.g. all packages upgraded by \fIpacman -Syu\fR).
+
+.SH "OPTIONS"
+.TP
+\fB\-i\fR
+Enter interactive mode to select package operations to undo (default behavior)
+.TP
+\fB\-r\fR
+Non-interactively undo entire transactions
+.TP
+\fB\-t\fR <\fInum\fR>
+Specify the number of transactions to include (default: 1)
+.TP
+\fB\-d\fR
+Dry run, i.e. don't actually do anything
+.TP
+\fB\-h\fR
+Show this help information
+.TP
+\fB\-v\fR
+Print program version
+
+.SH "AUTHOR"
+Written by Nicolás A. Ortega Froysa.
+
+.SH "COPYRIGHT"
+Copyright \(co 2024 Ortega Froysa, Nicolás A. <nicolas@ortegas.org>.
+License: ZLib License.
+
+This is free software: you are free to change and redistribute it.
+There is NO WARRANTY, to the extent permitted by law.

pacundo.pl

@@ -24,36 +24,232 @@
 
 use strict;
 use warnings;
+use feature qw(signatures);
 
 use Getopt::Std;
 use File::ReadBackwards;
 
-my $VERSION = "1.0";
-my $PROG_NAME = "pacundo";
+my $VERSION   = '1.1.1';
+my $PROG_NAME = 'pacundo';
 
-my $r_flag = 0;
-my $dry_run = 0;
-my $num_txs = 1;
-
-sub print_version {
+sub print_version() {
 	print("$PROG_NAME v$VERSION\n");
+	return;
 }
 
-sub print_help {
+sub print_help() {
 	&print_version();
-	print("A time machine to return your ArchLinux machine back to a working state.\n");
-	print("\nUSAGE:
+	print("A time machine to roll back your ArchLinux machine 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]
+	-i         Enter interactive mode to select package operations to undo (default behavior)
+	-r         Non-interactively undo entire transactions
+	-t <num>   Specify the number of transactions to include (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 $pacman_log = File::ReadBackwards->new('/var/log/pacman.log') or
+		die("Failed to load pacman log file.\n$!\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> ");
+
+	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;
+}
+
+# NOTE: Currently this subroutine only works for pacman and yay. You'll have to
+# add options for additional AUR helpers.
+sub get_pkgmgr() {
+	my $mgr = '';
+	my $mgr_bin;
+	my @supported_mgrs = (
+		'yay',
+		'pacman',
+	);
+	my $sudo = '';
+	my $user = $ENV{LOGNAME} || $ENV{USER};
+
+	foreach my $i (@supported_mgrs) {
+		$mgr_bin = `which $i 2>&1`;
+		if ($? == 0) {
+			$mgr = $i;
+			last;
+		}
+	}
+
+	if ($mgr eq '') {
+		print(STDERR "Failed to find pacman executable. Are you using an ArchLinux system?\n");
+		exit 1;
+	}
+	chomp($mgr_bin);
+
+	if ($mgr eq 'pacman' && $user ne 'root') {
+		$sudo = 'sudo';
+	}
+
+	my %pkgmgr = (
+		name           => $mgr,
+		bin            => $mgr_bin,
+		search         => "$mgr_bin -Ss",
+		info           => "$mgr_bin -Si",
+		install_remote => "$sudo $mgr_bin -S",
+		install_local  => "$sudo $mgr_bin -U",
+		remove         => "$sudo $mgr_bin -R",
+	);
+
+	return \%pkgmgr;
+}
+
+sub find_local_pkg($pkgmgr, $pkg_name, $pkg_ver='') {
+	my $pkg_file = '';
+	my $pkg_pat;
+	my $repo = `$pkgmgr->{info} $pkg_name | awk '{ if (\$1 == "Repository") print \$3; }'`;;
+	chomp($repo);
+
+	if ($pkg_ver ne '') {
+		$pkg_pat = "$pkg_name-$pkg_ver-*.pkg.tar.zst";
+	} else {
+		$pkg_pat = "$pkg_name-*.pkg.tar.zst";
+	}
+
+	if ($repo eq 'aur') {
+		my $aur_dir;
+
+		if ($pkgmgr->{name} eq 'yay') {
+			if ($ENV{'XDG_CACHE_HOME'} ne '') {
+				$aur_dir = "$ENV{'XDG_CACHE_HOME'}/yay/$pkg_name";
+			} else {
+				$aur_dir = "$ENV{'HOME'}/.cache/yay/$pkg_name";
+			}
+		} else {
+			return '';
+		}
+
+		$pkg_file = `ls $aur_dir/$pkg_pat 2> /dev/null | tail -n1`;
+	} else {
+		$pkg_file = `ls /var/cache/pacman/pkg/$pkg_pat 2> /dev/null | tail -n1`;
+	}
+
+	chomp($pkg_file);
+
+	return $pkg_file;
+}
+
+sub find_remote_archive($pkgmgr, $pkg_name, $pkg_ver) {
+	my $repo = `$pkgmgr->{info} $pkg_name | awk '{ if (\$1 == "Repository") print \$3; }'`;;
+	chomp($repo);
+	# TODO: look through git history for version.
+	if ($repo eq 'aur') {
+		return '';
+	}
+
+	# TODO: Probably a better way of managing architectures. There should be a
+	# way of getting the architecture of the package.
+	my @archs = (`uname -m`, 'any');
+	my $ala_url = "https://archive.archlinux.org/packages/" .
+		substr($pkg_name,0,1) . "/" . $pkg_name;
+	my $pkg_file = '';
+
+	foreach my $arch (@archs) {
+		chomp($arch);
+		my $filename = "$pkg_name-$pkg_ver-$arch.pkg.tar.zst";
+		my $pkg_url = "$ala_url/$filename";
+		my $output_file = "/tmp/$filename";
+
+		my $resp = `curl -Lo $output_file -s -w '%{http_code}\n' $pkg_url`;
+		chomp($resp);
+		if ($resp eq '200') {
+			system("curl -Lo $output_file.sig -s $pkg_url.sig");
+			$pkg_file = $output_file;
+			last;
+		} else {
+			unlink $output_file;
+		}
+	}
+
+	if ($pkg_file ne '') {
+		print("Downloaded from archive: $pkg_file\n");
+	}
+	return $pkg_file;
 }
 
 getopts("irt:dvh", \my %opts);
@@ -73,44 +269,48 @@ if ($opts{'v'}) {
 	exit 1;
 }
 
-$r_flag = 1 if ($opts{'r'});
-$dry_run = 1 if ($opts{'d'});
-$num_txs = $opts{'t'} if ($opts{'t'});
+my $r_flag  = $opts{'r'} // 0;
+my $dry_run = $opts{'d'} // 0;
+my $num_txs = $opts{'t'} // 1;
 
-my $pacman_log = File::ReadBackwards->new("/var/log/pacman.log") or
-die("Failed to load pacman log file.\n$!");
+my $pkgmgr = &get_pkgmgr();
+my @undo_txs = &read_txs($num_txs);
 
-my $found_txs = 0;
-my $in_tx = 0;
+# Interactive mode
+@undo_txs = &select_txs(@undo_txs) unless ($r_flag);
 
-my @undo_txs;
+my $remove_pkgs = "";          # executed via -R
+my $remote_install_pkgs = "";  # executed via -S
+my $local_install_pkgs = "";   # executed via -U
 
-while ($found_txs < $num_txs && defined(my $line = $pacman_log->readline)) {
-	# Remeber that we're reading this in reverse order
-	if (!$in_tx && $line =~ /\[ALPM\] transaction completed/) {
-		$in_tx = 1;
-	} elsif ($in_tx) {
-		if ($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,
-				}
-			);
+foreach my $tx (@undo_txs) {
+	if ($tx->{action} eq 'installed') {
+		$remove_pkgs .= "$tx->{pkg_name} ";
+	} elsif ($tx->{action} eq 'removed') {
+		my $pkg_file = &find_local_pkg($pkgmgr, $tx->{pkg_name});
+		if ($pkg_file eq '') {
+			$remote_install_pkgs .= "$tx->{pkg_name} ";
+		} else {
+			$local_install_pkgs .= "$pkg_file ";
+		}
+	} else {
+		my $pkg_file = &find_local_pkg($pkgmgr, $tx->{pkg_name}, $tx->{oldver});
+		$pkg_file = &find_remote_archive($pkgmgr, $tx->{pkg_name}, $tx->{oldver}) if ($pkg_file eq '');
+
+		if ($pkg_file ne '') {
+			$local_install_pkgs .= "$pkg_file ";
+		} else {
+			print(STDERR "Unable to find $tx->{pkg_name} $tx->{pkg_ver}");
 		}
 	}
 }
+
+if ($dry_run) {
+	print("$pkgmgr->{remove} $remove_pkgs\n") if ($remove_pkgs ne '');
+	print("$pkgmgr->{install_remote} $remote_install_pkgs\n") if ($remote_install_pkgs ne '');
+	print("$pkgmgr->{install_local} $local_install_pkgs\n") if ($local_install_pkgs ne '');
+} else {
+	system("$pkgmgr->{remove} $remove_pkgs") if ($remove_pkgs ne '');
+	system("$pkgmgr->{install_remote} $remote_install_pkgs") if ($remote_install_pkgs ne '');
+	system("$pkgmgr->{install_local} $local_install_pkgs") if ($local_install_pkgs ne '');
+}