+# alias expansion and command stemming
+my $action=shift @ARGV;
+if (exists $alias{$action}) {
+ $action=$alias{$action};
+}
+if (! exists $knownactions{$action}) {
+ my @matches = grep { /^\Q$action\E/ }
+ keys %knownactions, keys %alias;
+ if (@matches == 1) {
+ $action=$matches[0];
+ }
+ elsif (@matches == 0) {
+ die "mr: unknown action \"$action\" (known actions: ".
+ join(", ", sort keys %knownactions).")\n";
+ }
+ else {
+ die "mr: ambiguous action \"$action\" (matches: ".
+ join(", ", @matches).")\n";
+ }
+}
+
+# commands that do not operate on all repos
+if ($action eq 'help') {
+ exec($config{''}{DEFAULT}{$action}) || die "exec: $!";
+}
+elsif ($action eq 'config') {
+ if (@ARGV < 2) {
+ die "mr config: not enough parameters\n";
+ }
+ my $section=shift;
+ if ($section=~/^\//) {
+ # try to convert to a path relative to the config file
+ my ($dir)=$ENV{MR_CONFIG}=~/^(.*\/)[^\/]+$/;
+ $dir=abs_path($dir);
+ $dir.="/" unless $dir=~/\/$/;
+ if ($section=~/^\Q$dir\E(.*)/) {
+ $section=$1;
+ }
+ }
+ my %changefields;
+ foreach (@ARGV) {
+ if (/^([^=]+)=(.*)$/) {
+ $changefields{$1}=$2;
+ }
+ else {
+ my $found=0;
+ foreach my $topdir (sort keys %config) {
+ if (exists $config{$topdir}{$section} &&
+ exists $config{$topdir}{$section}{$_}) {
+ print $config{$topdir}{$section}{$_}."\n";
+ $found=1;
+ last if $section eq 'DEFAULT';
+ }
+ }
+ if (! $found) {
+ die "mr $action: $section $_ not set\n";
+ }
+ }
+ }
+ modifyconfig($ENV{MR_CONFIG}, $section, %changefields) if %changefields;
+ exit 0;
+}
+elsif ($action eq 'register') {
+ if (! $config_overridden) {
+ # Find the closest known mrconfig file to the current
+ # directory.
+ $directory.="/" unless $directory=~/\/$/;
+ foreach my $topdir (reverse sort keys %config) {
+ next unless length $topdir;
+ if ($directory=~/^\Q$topdir\E/) {
+ $ENV{MR_CONFIG}=$configfiles{$topdir};
+ last;
+ }
+ }
+ }
+ my $command="set -e; ".$config{''}{DEFAULT}{lib}."\n".
+ "my_action(){ $config{''}{DEFAULT}{$action}\n }; my_action ".
+ join(" ", map { s/\//\/\//g; s/"/\"/g; '"'.$_.'"' } @ARGV);
+ print STDERR "mr $action: running >>$command<<\n" if $verbose;
+ exec($command) || die "exec: $!";
+}
+
+# work out what repos to act on
+my @repos;
+my $nochdir=0;