libreCMC/scripts/feeds

#!/usr/bin/env perl
use Getopt::Std;
use FindBin;
use Cwd;
use lib "$FindBin::Bin";
use metadata;
use warnings;
use strict;
use Cwd 'abs_path';

chdir "$FindBin::Bin/..";
$ENV{TOPDIR} //= getcwd();
chdir $ENV{TOPDIR};
$ENV{GIT_CONFIG_PARAMETERS}="'core.autocrlf=false'";
$ENV{GREP_OPTIONS}="";

my $mk=`which gmake 2>/dev/null`;	# select the right 'make' program
chomp($mk);		# trim trailing newline
$mk or $mk = "make";	# default to 'make'

# check version of make
my @mkver = split /\s+/, `$mk -v`, 4;
my $valid_mk = 1;
$mkver[0] =~ /^GNU/ or $valid_mk = 0;
$mkver[1] =~ /^Make/ or $valid_mk = 0;

my ($mkv1, $mkv2) = split /\./, $mkver[2];
($mkv1 >= 4 || ($mkv1 == 3 && $mkv2 >= 81)) or $valid_mk = 0;

$valid_mk or die "Unsupported version of make found: $mk\n";

my @feeds;
my %build_packages;
my %installed;
my %installed_targets;
my %feed_cache;

my $feed_package = {};
my $feed_src = {};
my $feed_target = {};

sub parse_config() {
	my $line = 0;
	my %name;

	open FEEDS, "feeds.conf" or
		open FEEDS, "feeds.conf.default" or
		die "Unable to open feeds configuration";
	while (<FEEDS>) {
		chomp;
		s/#.+$//;
		next unless /\S/;
		my @line = split /\s+/, $_, 3;
		my @src;
		$line++;

		my $valid = 1;
		$line[0] =~ /^src-[\w-]+$/ or $valid = 0;
		$line[1] =~ /^\w+$/ or $valid = 0;
		@src = split /\s+/, $line[2];
		$valid or die "Syntax error in feeds.conf, line: $line\n";

		$name{$line[1]} and die "Duplicate feed name '$line[1]', line: $line\n";
		$name{$line[1]} = 1;

		push @feeds, [$line[0], $line[1], \@src];
	}
	close FEEDS;
}

sub update_location($$)
{
	my $name = shift;
	my $url  = shift;
	my $old_url;

	-d "./feeds/$name.tmp" or mkdir "./feeds/$name.tmp" or return 1;

	if( open LOC, "< ./feeds/$name.tmp/location" )
	{
		chomp($old_url = readline LOC);
		close LOC;
	}

	if( !$old_url || $old_url ne $url )
	{
		if( open LOC, "> ./feeds/$name.tmp/location" )
		{
			print LOC $url, "\n";
			close LOC;
		}
		return $old_url ? 1 : 0;
	}

	return 0;
}

sub update_index($)
{
	my $name = shift;

	-d "./feeds/$name.tmp" or mkdir "./feeds/$name.tmp" or return 1;
	-d "./feeds/$name.tmp/info" or mkdir "./feeds/$name.tmp/info" or return 1;

	system("$mk -s prepare-mk OPENWRT_BUILD= TMP_DIR=\"$ENV{TOPDIR}/feeds/$name.tmp\"");
	system("$mk -s -f include/scan.mk IS_TTY=1 SCAN_TARGET=\"packageinfo\" SCAN_DIR=\"feeds/$name\" SCAN_NAME=\"package\" SCAN_DEPS=\"$ENV{TOPDIR}/include/package*.mk\" SCAN_DEPTH=5 SCAN_EXTRA=\"\" TMP_DIR=\"$ENV{TOPDIR}/feeds/$name.tmp\"");
	system("$mk -s -f include/scan.mk IS_TTY=1 SCAN_TARGET=\"targetinfo\" SCAN_DIR=\"feeds/$name\" SCAN_NAME=\"target\" SCAN_DEPS=\"profiles/*.mk $ENV{TOPDIR}/include/target.mk\" SCAN_DEPTH=5 SCAN_EXTRA=\"\" SCAN_MAKEOPTS=\"TARGET_BUILD=1\" TMP_DIR=\"$ENV{TOPDIR}/feeds/$name.tmp\"");
	system("ln -sf $name.tmp/.packageinfo ./feeds/$name.index");
	system("ln -sf $name.tmp/.targetinfo ./feeds/$name.targetindex");

	return 0;
}

my %update_method = (
	'src-svn' => {
		'init'		=> "svn checkout '%s' '%s'",
		'update'	=> "svn update",
		'controldir'	=> ".svn",
		'revision'	=> "svn info | grep 'Revision' | cut -d ' ' -f 2 | tr -d '\n'"},
	'src-cpy' => {
		'init'		=> "cp -Rf '%s' '%s'",
		'update'	=> "",
		'revision'	=> "echo -n 'local'"},
	'src-link' => {
		'init'		=> "ln -s '%s' '%s'",
		'update'	=> "",
		'revision'	=> "echo -n 'local'"},
	'src-git' => {
		'init'          => "git clone --depth 1 '%s' '%s'",
		'init_branch'   => "git clone --depth 1 --branch '%s' '%s' '%s'",
		'init_commit'   => "git clone '%s' '%s' && cd '%s' && git checkout -b '%s' '%s' && cd -",
		'update'	=> "git pull --ff",
		'controldir'	=> ".git",
		'revision'	=> "git rev-parse --short HEAD | tr -d '\n'"},
	'src-git-full' => {
		'init'          => "git clone '%s' '%s'",
		'init_branch'   => "git clone --branch '%s' '%s' '%s'",
		'init_commit'   => "git clone '%s' '%s' && cd '%s' && git checkout -b '%s' '%s' && cd -",
		'update'	=> "git pull --ff",
		'controldir'	=> ".git",
		'revision'	=> "git rev-parse --short HEAD | tr -d '\n'"},
	'src-gitsvn' => {
		'init'	=> "git svn clone -r HEAD '%s' '%s'",
		'update'	=> "git svn rebase",
		'controldir'	=> ".git",
		'revision'	=> "git rev-parse --short HEAD | tr -d '\n'"},
	'src-bzr' => {
		'init'		=> "bzr checkout --lightweight '%s' '%s'",
		'update'	=> "bzr update",
		'controldir'	=> ".bzr"},
	'src-hg' => {
		'init'		=> "hg clone '%s' '%s'",
		'update'	=> "hg pull --update",
		'controldir'	=> ".hg"},
	'src-darcs' => {
		'init'    => "darcs get '%s' '%s'",
		'update'  => "darcs pull -a",
		'controldir' => "_darcs"},
);

# src-git: pull broken
# src-cpy: broken if `basename $src` != $name

sub update_feed_via($$$$) {
	my $type = shift;
	my $name = shift;
	my $src = shift;
	my $relocate = shift;

	my $m = $update_method{$type};
	my $localpath = "./feeds/$name";
	my $safepath = $localpath;
	$safepath =~ s/'/'\\''/;
	my ($base_branch, $branch) = split(/;/, $src, 2);
	my ($base_commit, $commit) = split(/\^/, $src, 2);

	if( $relocate || !$m->{'update'} || !-d "$localpath/$m->{'controldir'}" ) {
		system("rm -rf '$safepath'");
		if ($m->{'init_branch'} and $branch) {
			system(sprintf($m->{'init_branch'}, $branch, $base_branch, $safepath)) == 0 or return 1;
		} elsif ($m->{'init_commit'} and $commit) {
			system(sprintf($m->{'init_commit'}, $base_commit, $safepath, $safepath, $commit, $commit)) == 0 or return 1;
		} else {
			system(sprintf($m->{'init'}, $src, $safepath)) == 0 or return 1;
		}
	} elsif ($m->{'init_commit'} and $commit) {
		# in case git hash has been provided don't update the feed
	} else {
		system("cd '$safepath'; $m->{'update'}") == 0 or return 1;
	}

	return 0;
}

sub get_targets($) {
	my $file = shift;
	my @target = parse_target_metadata($file);
	my %target;
	foreach my $target (@target) {
		$target{$target->{id}} = $target;
	}
	return %target
}

sub get_feed($) {
	my $feed = shift;

	if (!defined($feed_cache{$feed})) {
		my $file = "./feeds/$feed.index";

		clear_packages();
		-f $file or do {
			print "Ignoring feed '$feed' - index missing\n";
			return;
		};
		parse_package_metadata($file) or return;
		my %target = get_targets("./feeds/$feed.targetindex");

		$feed_cache{$feed} = [ { %package }, { %srcpackage }, { %target } ];
	}

	$feed_package = $feed_cache{$feed}->[0];
	$feed_src = $feed_cache{$feed}->[1];
	$feed_target = $feed_cache{$feed}->[2];
	return $feed_cache{$feed}->[0];
}

sub get_installed() {
	system("$mk -s prepare-tmpinfo OPENWRT_BUILD=");
	clear_packages();
	parse_package_metadata("./tmp/.packageinfo");
	%installed = %package;
	%installed_targets = get_targets("./tmp/.targetinfo");
}

sub search_feed {
	my $feed = shift;
	my @substr = @_;
	my $display;

	return unless @substr > 0;
	get_feed($feed);
	foreach my $name (sort { lc($a) cmp lc($b) } keys %$feed_package) {
		my $pkg = $feed_package->{$name};
		my $substr;
		my $pkgmatch = 1;

		next if $pkg->{vdepends};
		foreach my $substr (@substr) {
			my $match;
			foreach my $key (qw(name title description src)) {
				$pkg->{$key} and $substr and $pkg->{$key} =~ m/$substr/i and $match = 1;
			}
			$match or undef $pkgmatch;
		};
		$pkgmatch and do {
			$display or do {
				print "Search results in feed '$feed':\n";
				$display = 1;
			};
			printf "\%-25s\t\%s\n", $pkg->{name}, $pkg->{title};
		};
	}

	foreach my $name (sort { lc($a) cmp lc($b) } keys %$feed_target) {
		my $target = $feed_target->{$name};
		my $targetmatch = 1;

		foreach my $substr (@substr) {
			my $match;
			foreach my $key (qw(id name description)) {
				$target->{$key} and $substr and $target->{$key} =~ m/$substr/i and $match = 1;
			}
			$match or undef $targetmatch;
		};
		$targetmatch and do {
			$display or do {
				print "Search results in feed '$feed':\n";
				$display = 1;
			};
			printf "TARGET: \%-17s\t\%s\n", $target->{id}, $target->{name};
		};
	}
	return 0;
}

sub search {
	my %opts;

	getopt('r:', \%opts);
	foreach my $feed (@feeds) {
		search_feed($feed->[1], @ARGV) if (!defined($opts{r}) or $opts{r} eq $feed->[1]);
	}
}

sub list_feed {
	my $feed = shift;

	get_feed($feed);
	foreach my $name (sort { lc($a) cmp lc($b) } keys %$feed_package) {
		my $pkg = $feed_package->{$name};
		next if $pkg->{vdepends};
		if($pkg->{name}) {
			printf "\%-32s\t\%s\n", $pkg->{name}, $pkg->{title};
		}
	}

	foreach my $name (sort { lc($a) cmp lc($b) } keys %$feed_target) {
		my $target = $feed_target->{$name};
		if($target->{name}) {
			printf "TARGET: \%-24s\t\%s\n", $target->{id}, $target->{name};
		}
	}

	return 0;
}

sub list {
	my %opts;

	getopts('r:d:nshf', \%opts);
	if ($opts{h}) {
		usage();
		return 0;
	}
	if ($opts{n}) {
		foreach my $feed (@feeds) {
			printf "%s\n", $feed->[1];
		}
		return 0;
	}
	if ($opts{s}) {
		foreach my $feed (@feeds) {
			my $localpath = "./feeds/$feed->[1]";
			my $m = $update_method{$feed->[0]};
			my $revision;
			if (!-d "$localpath" || !$m->{'revision'}) {
				$revision = "X";
			}
			elsif( $m->{'controldir'} && -d "$localpath/$m->{'controldir'}" ) {
				$revision = `cd '$localpath'; $m->{'revision'}`;
			}
			else {
				$revision = "local";
			}
			if ($opts{d}) {
				printf "%s%s%s%s%s%s%s\n", $feed->[1], $opts{d}, $feed->[0], $opts{d}, $revision, $opts{d}, join(", ", @{$feed->[2]});
			}
			elsif ($opts{f}) {
				my $uri = join(", ", @{$feed->[2]});
				if ($revision ne "local" && $revision ne "X") {
					$uri =~ s/[;^].*//;
					$uri .= "^" . $revision;
				}
				printf "%s %s %s\n", $feed->[0], $feed->[1], $uri;
			}
			else {
				printf "\%-10s \%-8s \%-8s \%s\n", $feed->[1], $feed->[0], $revision, join(", ", @{$feed->[2]});
			}
		}
		return 0;
	}
	foreach my $feed (@feeds) {
		list_feed($feed->[1], @ARGV) if (!defined($opts{r}) or $opts{r} eq $feed->[1]);
	}
	return 0;
}

sub do_install_package($$) {
	my $feed = shift;
	my $pkg = shift;
	my $path = $pkg->{makefile};

	if($path) {
		$path =~ s/\/Makefile$//;

		-d "./package/feeds" or mkdir "./package/feeds";
		-d "./package/feeds/$feed->[1]" or mkdir "./package/feeds/$feed->[1]";
		system("ln -sf ../../../$path ./package/feeds/$feed->[1]/");
	} else {
		warn "Package is not valid\n";
		return 1;
	}

	return 0;
}

sub do_install_target($) {
	my $target = shift;
	my $path = $target->{makefile};

	if ($path) {
		$path =~ s/\/Makefile$//;
		my $name = $path;
		$name =~ s/.*\///;
		my $dest = "./target/linux/$name";

		-e $dest and do {
			warn "Path $dest already exists";
			return 1;
		};

		system("ln -sf ../../$path ./target/linux/");
	} else {
		warn "Target is not valid\n";
		return 1;
	}

	return 0;
}

sub lookup_package($$) {
	my $feed = shift;
	my $package = shift;

	foreach my $feed ($feed, @feeds) {
		next unless $feed->[1];
		next unless $feed_cache{$feed->[1]};
		$feed_cache{$feed->[1]}->[0]->{$package} and return $feed;
	}
	return;
}

sub lookup_target($$) {
	my $feed = shift;
	my $target = shift;

	foreach my $feed ($feed, @feeds) {
		next unless $feed->[1];
		next unless $feed_cache{$feed->[1]};
		$feed_cache{$feed->[1]}->[2]->{$target} and return $feed;
	}
	return;
}

sub is_core_package($) {
	my $package = shift;
	foreach my $file ("tmp/info/.packageinfo-$package", glob("tmp/info/.packageinfo-*_$package")) {
		next unless index($file, "tmp/info/.packageinfo-feeds_");
		return 1 if -s $file;
	}
	return 0;
}

sub install_target {
	my $feed = shift;
	my $name = shift;

	$feed = $feed_cache{$feed->[1]}->[2];
	$feed or return 0;

	my $target = $feed->{$name};
	$target or return 0;

	warn "Installing target '$name'\n";
	return do_install_target($target);
}

sub install_package {
	my $feed = shift;
	my $name = shift;
	my $force = shift;
	my $ret = 0;

	my $this_feed_target = lookup_target($feed, $name);
	$this_feed_target and do {
		$installed_targets{$name} and return 0;
		install_target($this_feed_target, $name);
		return 0;
	};

	$feed = lookup_package($feed, $name);
	$feed or do {
		$installed{$name} and return 0;
		# TODO: check if it's already installed within ./package directory
		$feed_src->{$name} or is_core_package($name) or warn "WARNING: No feed for package '$name' found, maybe it's already part of the standard packages?\n";
		return 0;
	};

	# switch to the metadata for the selected feed
	my $cur = get_feed($feed->[1]);

	my $pkg = $cur->{$name} or return 1;
	$pkg->{name} or do {
		$installed{$name} and return 0;
		# TODO: check if this is an alias package, maybe it's known by another name
		warn "WARNING: Package '$name' is not available in feed $feed->[1].\n";
		return 0;
	};
	my $src = $pkg->{src};
	my $type = $feed->[0];
	$src or $src = $name;

	# If it's a core package and we don't want to override, just return
	!$force and is_core_package($src) and return 0;

	# previously installed packages set the runtime package
	# newly installed packages set the source package to 1
	$installed{$src} and $installed{$src} == 1 and return 0;

	# we'll trigger the override only with the 3 conditions below:
	# - override is allowed by command line (-f)
	# - a package with the same src exists in the core packages list
	# - the package previously installed is not from a feed
	my $override = 1 if ($force and is_core_package($src) and !$installed{$name}->{feed});

	# check previously installed packages
	$installed{$name} and !$override and return 0;
	$installed{$src} = 1;

	defined($override) and $override == 1
		and warn "Overriding core package '$src' with version from $feed->[1]\n"
		or warn "Installing package '$src' from $feed->[1]\n";

	do_install_package($feed, $pkg) == 0 or do {
		warn "failed.\n";
		return 1;
	};

	# install all dependencies referenced from the source package
	foreach my $vpkg (@{$feed_src->{$src}}) {
		foreach my $dep (@{$vpkg->{depends}}, @{$vpkg->{builddepends}}, @{$vpkg->{"builddepends/host"}}) {
			next if $dep =~ /@/;
			$dep =~ s/^\+//;
			$dep =~ s/^.+://;
			$dep =~ s/\/.+$//;
			next unless $dep;
			install_package($feed, $dep, 0) == 0 or $ret = 1;
		}
	}

	return $ret;
}

sub refresh_config {
	my $default = shift;

	# Don't create .config if it doesn't already exist so that making a
	# config only occurs when the user intends it do (however we do
	# want to refresh an existing config).
	return if not (-e '.config');

	# workaround for timestamp check
	system("rm -f tmp/.packageinfo");

	# refresh the config
	if ($default) {
		system("$mk oldconfig CONFDEFAULT=\"$default\" Config.in >/dev/null 2>/dev/null");
	} else {
		system("$mk defconfig Config.in >/dev/null 2>/dev/null");
	}
}

sub install {
	my $name;
	my %opts;
	my $feed;
	my $ret = 0;

	getopts('ap:d:fh', \%opts);

	if ($opts{h}) {
		usage();
		return 0;
	}

	get_installed();

	foreach my $f (@feeds) {
		# fetch all feeds
		get_feed($f->[1]);

		# look up the preferred feed
		$opts{p} and $f->[1] eq $opts{p} and $feed = $f;
	}

	if($opts{a}) {
		foreach my $f (@feeds) {
			if (!defined($opts{p}) or $opts{p} eq $f->[1]) {
				printf "Installing all packages from feed %s.\n", $f->[1];
				get_feed($f->[1]);
				foreach my $name (sort { lc($a) cmp lc($b) } keys %$feed_package) {
					my $p = $feed_package->{$name};
					next if $p->{vdepends};
					if( $p->{name} ) {
						install_package($feed, $p->{name}, exists($opts{f})) == 0 or $ret = 1;
						get_feed($f->[1]);
					}
				}
			}
		}
	} else {
		while ($name = shift @ARGV) {
			install_package($feed, $name, exists($opts{f})) == 0 or $ret = 1;
		}
	}

	# workaround for timestamp check

	# set the defaults
	if ($opts{d} and $opts{d} =~ /^[ymn]$/) {
		refresh_config($opts{d});
	}

	return $ret;
}

sub uninstall_target($) {
	my $dir = shift;
	my $name = $dir;
	$name =~ s/.*\///g;

	my $dest = readlink $dir;
	return unless $dest =~ /..\/..\/feeds/;
	warn "Uninstalling target '$name'\n";
	unlink "$dir";
}

sub uninstall {
	my %opts;
	my $name;
	my $uninstall;

	getopts('ah', \%opts);

	if ($opts{h}) {
		usage();
		return 0;
	}

	if ($opts{a}) {
		system("rm -rvf ./package/feeds");
		foreach my $dir (glob "target/linux/*") {
			next unless -l $dir;
			uninstall_target($dir);
		}
		$uninstall = 1;
	} else {
		if($#ARGV == -1) {
			warn "WARNING: no package to uninstall\n";
			return 0;
		}
		get_installed();
		while ($name = shift @ARGV) {
			my $target = "target/linux/$name";
			-l "$target" and do {
				uninstall_target($target);
				$uninstall = 1;
				next;
			};

			my $pkg = $installed{$name};
			$pkg or do {
				warn "WARNING: $name not installed\n";
				next;
			};
			$pkg->{src} and $name = $pkg->{src};
			warn "Uninstalling package '$name'\n";
			system("rm -f ./package/feeds/*/$name");
			$uninstall = 1;
		}
	}
	$uninstall and refresh_config();
	return 0;
}

sub update_feed($$$$)
{
	my $type=shift;
	my $name=shift;
	my $src=shift;
	my $perform_update=shift;
	my $force_relocate=update_location( $name, "@$src" );

	if( $force_relocate ) {
		warn "Source of feed $name has changed, replacing copy\n";
	}
	$update_method{$type} or do {
		warn "Unknown type '$type' in feed $name\n";
		return 1;
	};
	$perform_update and do {
		my $failed = 1;
		foreach my $feedsrc (@$src) {
			warn "Updating feed '$name' from '$feedsrc' ...\n";
			next unless update_feed_via($type, $name, $feedsrc, $force_relocate) == 0;
			$failed = 0;
			last;
		}
		$failed and do {
			warn "failed.\n";
			return 1;
		};
	};
	warn "Create index file './feeds/$name.index' \n";
	update_index($name) == 0 or do {
		warn "failed.\n";
		return 1;
	};
	return 0;
}

sub update {
	my %opts;
	my $feed_name;
	my $perform_update=1;
	my $failed=0;

	$ENV{SCAN_COOKIE} = $$;
	$ENV{OPENWRT_VERBOSE} = 's';

	getopts('ahi', \%opts);

	if ($opts{h}) {
		usage();
		return 0;
	}

	if ($opts{i}) {
		# don't update from (remote) repository
		# only re-create index information
		$perform_update=0;
	}

	-d "feeds" or do {
			mkdir "feeds" or die "Unable to create the feeds directory";
		};

	if ( ($#ARGV == -1) or $opts{a}) {
		foreach my $feed (@feeds) {
			my ($type, $name, $src) = @$feed;
			update_feed($type, $name, $src, $perform_update) == 0 or $failed=1;
		}
	} else {
		while ($feed_name = shift @ARGV) {
			foreach my $feed (@feeds) {
				my ($type, $name, $src) = @$feed;
				if($feed_name ne $name) {
					next;
				}
				update_feed($type, $name, $src, $perform_update) == 0 or $failed=1;
			}
		}
	}

	refresh_config();

	return $failed;
}

sub feed_config() {
	foreach my $feed (@feeds) {
		my $installed = (-f "feeds/$feed->[1].index");

		printf "\tconfig FEED_%s\n", $feed->[1];
		printf "\t\tbool \"Enable feed %s\"\n", $feed->[1];
		printf "\t\tdepends on PER_FEED_REPO\n";
		printf "\t\tdefault y\n" if $installed;
		printf "\t\thelp\n";
		printf "\t\t Enable the \\\"%s\\\" feed at %s.\n", $feed->[1], $feed->[2][0];
		printf "\n";
	}

	return 0;
}

sub usage() {
	print <<EOF;
Usage: $0 <command> [options]

Commands:
	list [options]: List feeds, their content and revisions (if installed)
	Options:
	    -n :            List of feed names.
	    -s :            List of feed names and their URL.
	    -r <feedname>:  List packages of specified feed.
	    -d <delimiter>: Use specified delimiter to distinguish rows (default: spaces)
	    -f :            List feeds in feeds.conf compatible format (when using -s).

	install [options] <package>: Install a package
	Options:
	    -a :           Install all packages from all feeds or from the specified feed using the -p option.
	    -p <feedname>: Prefer this feed when installing packages.
	    -d <y|m|n>:    Set default for newly installed packages.
	    -f :           Install will be forced even if the package exists in core OpenWrt (override)

	search [options] <substring>: Search for a package
	Options:
	    -r <feedname>: Only search in this feed

	uninstall -a|<package>: Uninstall a package
	Options:
	    -a :           Uninstalls all packages.

	update -a|<feedname(s)>: Update packages and lists of feeds in feeds.conf .
	Options:
	    -a :           Update all feeds listed within feeds.conf. Otherwise the specified feeds will be updated.
	    -i :           Recreate the index only. No feed update from repository is performed.

	clean:             Remove downloaded/generated files.

EOF
	exit(1);
}

my %commands = (
	'list' => \&list,
	'update' => \&update,
	'install' => \&install,
	'search' => \&search,
	'uninstall' => \&uninstall,
	'feed_config' => \&feed_config,
	'clean' => sub {
		system("rm -rf ./feeds ./package/feeds");
	}
);

my $arg = shift @ARGV;
$arg or usage();
parse_config;
foreach my $cmd (keys %commands) {
	$arg eq $cmd and do {
		exit(&{$commands{$cmd}}());
	};
}
usage();