openwrtv4/scripts/feeds
Matthias Schiffer 52719c2b67
metadata: scripts/feeds: distinguish between source and binary packages, resolve virtual dependencies
Properly resolve build depends to source packages and runtime depends to
binary packages. Dependencies on virtual packages are resolved to the first
provider now.

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
2018-01-13 19:54:45 +01:00

887 lines
21 KiB
Perl
Executable file

#!/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_pkg;
my %installed_targets;
my %feed_cache;
my $feed_package = {};
my $feed_src = {};
my $feed_target = {};
my $feed_vpackage = {};
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",
'update_force' => "git pull --ff || (git reset --hard HEAD; git pull --ff; exit 1)",
'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",
'update_force' => "git pull --ff || (git reset --hard HEAD; git pull --ff; exit 1)",
'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 $force = 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 {
my $update_cmd = $m->{'update'};
if ($force && exists $m->{'update_force'}) {
$update_cmd = $m->{'update_force'};
}
system("cd '$safepath'; $update_cmd") == 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 }, { %vpackage } ];
}
$feed_package = $feed_cache{$feed}->[0];
$feed_src = $feed_cache{$feed}->[1];
$feed_target = $feed_cache{$feed}->[2];
$feed_vpackage = $feed_cache{$feed}->[3];
}
sub get_installed() {
system("$mk -s prepare-tmpinfo OPENWRT_BUILD=");
clear_packages();
parse_package_metadata("./tmp/.packageinfo");
%installed_pkg = %vpackage;
%installed = %srcpackage;
%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;
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};
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_src($$) {
my $feed = shift;
my $src = shift;
my $path = $src->{makefile};
if ($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_src($$) {
my $feed = shift;
my $src = shift;
foreach my $feed ($feed, @feeds) {
next unless $feed->[1];
next unless $feed_cache{$feed->[1]};
$feed_cache{$feed->[1]}->[1]->{$src} and return $feed;
}
return;
}
sub lookup_package($$) {
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]}->[3]->{$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_src($) {
my $src = shift;
foreach my $file ("tmp/info/.packageinfo-$src", glob("tmp/info/.packageinfo-*_$src")) {
next unless index($file, "tmp/info/.packageinfo-feeds_");
return 1 if -s $file;
}
return 0;
}
sub install_target {
my $feed = shift;
my $name = shift;
$installed_targets{$name} and return 0;
$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_src {
my $feed = shift;
my $name = shift;
my $force = shift;
my $ret = 0;
$feed = lookup_src($feed, $name);
unless ($feed) {
$installed{$name} and return 0;
$feed_src->{$name} or warn "WARNING: No feed for source package '$name' found\n";
return 0;
}
# switch to the metadata for the selected feed
get_feed($feed->[1]);
my $src = $feed_src->{$name} or return 1;
# If it's a core package and we don't want to override, just return
my $override = 0;
if (is_core_src($name)) {
return 0 unless $force;
$override = 1;
}
if ($installed{$name}) {
# newly installed packages set the source package to 1
return 0 if ($installed{$name} == 1);
return 0 unless ($override);
}
$installed{$name} = 1;
foreach my $pkg (@{$src->{packages}}) {
foreach my $vpkg (@{$pkg->{provides}}) {
$installed_pkg{$vpkg} = 1;
}
}
if ($override) {
warn "Overriding core package '$name' with version from $feed->[1]\n";
} else {
warn "Installing package '$name' from $feed->[1]\n";
}
do_install_src($feed, $src) == 0 or do {
warn "failed.\n";
return 1;
};
# install all dependencies referenced from the source package
foreach my $dep (
@{$src->{builddepends}},
@{$src->{'builddepends/host'}},
) {
next if $dep =~ /@/;
$dep =~ s/^.+://;
$dep =~ s/\/.+$//;
next unless $dep;
install_src($feed, $dep, 0) == 0 or $ret = 1;
}
foreach my $pkg (@{$src->{packages}}) {
foreach my $dep (@{$pkg->{depends}}) {
next if $dep =~ /@/;
$dep =~ s/^\+//;
$dep =~ s/^.+://;
next unless $dep;
install_package($feed, $dep, 0) == 0 or $ret = 1;
}
}
return $ret;
}
sub install_package {
my $feed = shift;
my $name = shift;
my $force = shift;
$feed = lookup_package($feed, $name);
unless ($feed) {
$installed_pkg{$name} and return 0;
$feed_vpackage->{$name} or warn "WARNING: No feed for package '$name' found\n";
return 0;
}
# switch to the metadata for the selected feed
get_feed($feed->[1]);
my $pkg = $feed_vpackage->{$name} or return 1;
return install_src($feed, $pkg->[0]{src}{name}, $force);
}
sub install_target_or_package {
my $feed = shift;
my $name = shift;
my $force = shift;
my $this_feed_target = lookup_target($feed, $name);
$this_feed_target and do {
return install_target($this_feed_target, $name);
};
my $this_feed_src = lookup_src($feed, $name);
$this_feed_src or do {
return install_src($this_feed_src, $name, $force);
};
return install_package($feed, $name, $force);
}
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_src) {
install_src($feed, $name, exists($opts{f})) == 0 or $ret = 1;
get_feed($f->[1]);
}
}
}
} else {
while ($name = shift @ARGV) {
install_target_or_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}{name};
warn "Uninstalling package '$name'\n";
system("rm -f ./package/feeds/*/$name");
$uninstall = 1;
}
}
$uninstall and refresh_config();
return 0;
}
sub update_feed($$$$$)
{
my $type=shift;
my $name=shift;
my $src=shift;
my $perform_update=shift;
my $force_update=shift;
my $force_relocate=update_location( $name, "@$src" );
my $rv=0;
if( $force_relocate ) {
warn "Source of feed $name has changed, replacing copy\n";
}
$update_method{$type} or do {
warn "Unknown type '$type' in feed $name\n";
return 1;
};
$perform_update and do {
my $failed = 1;
foreach my $feedsrc (@$src) {
warn "Updating feed '$name' from '$feedsrc' ...\n";
if (update_feed_via($type, $name, $feedsrc, $force_relocate, $force_update) != 0) {
if ($force_update) {
$rv=1;
$failed=0;
warn "failed, ignore.\n";
next;
}
last;
}
$failed = 0;
}
$failed and do {
warn "failed.\n";
return 1;
};
};
warn "Create index file './feeds/$name.index' \n";
update_index($name) == 0 or do {
warn "failed.\n";
return 1;
};
return $rv;
}
sub update {
my %opts;
my $feed_name;
my $perform_update=1;
my $failed=0;
$ENV{SCAN_COOKIE} = $$;
$ENV{OPENWRT_VERBOSE} = 's';
getopts('ahif', \%opts);
if ($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, $opts{f}) == 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, $opts{f}) == 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.
-f : Force updating feeds even if there are changed, uncommitted files.
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();