mr: Check if unsafe ENV variables are set

[code/myrepos.git] / mr

#!/usr/bin/env perl

=head1 NAME

mr - a tool to manage all your version control repos

=head1 SYNOPSIS

B<mr> [options] checkout

B<mr> [options] update

B<mr> [options] status

B<mr> [options] clean [-f]

B<mr> [options] commit [-m "message"]

B<mr> [options] record [-m "message"]

B<mr> [options] fetch

B<mr> [options] push

B<mr> [options] diff

B<mr> [options] log

B<mr> [options] grep pattern

B<mr> [options] run command [param ...]

B<mr> [options] bootstrap src [directory]

B<mr> [options] register [repository]

B<mr> [options] config section ["setting=[value]" ...]

B<mr> [options] action [params ...]

B<mr> [options] [online|offline]

B<mr> [options] remember action [params ...]

=head1 DESCRIPTION

B<mr> is a tool to manage all your version control repos. It can checkout,
update, or perform other actions on a set of repositories as if they were
one combined repository. It supports any combination of subversion, git,
cvs, mercurial, bzr, darcs, fossil and veracity repositories, and support
for other version control systems can easily be added.

B<mr> cds into and operates on all registered repositories at or below your
working directory. Or, if you are in a subdirectory of a repository that
contains no other registered repositories, it will stay in that directory,
and work on only that repository,

B<mr> is configured by .mrconfig files, which list the repositories. It
starts by reading the .mrconfig file in your home directory, and this can
in turn chain load .mrconfig files from repositories. It also automatically
looks for a .mrconfig file in the current directory, or in one of its
parent directories.

These predefined commands should be fairly familiar to users of any version
control system:

=over 4

=item checkout (or co)

Checks out any repositories that are not already checked out.

=item update

Updates each repository from its configured remote repository.

If a repository isn't checked out yet, it will first check it out.

=item status

Displays a status report for each repository, showing what
uncommitted changes are present in the repository. For distributed version
control systems, also shows unpushed local branches.

=item clean

Print ignored files, untracked files and other cruft in the working directory.

The optional -f parameter allows removing the files as well as printing them.

=item commit (or ci)

Commits changes to each repository. (By default, changes are pushed to the
remote repository too, when using distributed systems like git. If you
don't like this default, you can change it in your .mrconfig, or use record
instead.)

The optional -m parameter allows specifying a commit message.

=item record

Records changes to the local repository, but does not push them to the
remote repository. Only supported for distributed version control systems.

The optional -m parameter allows specifying a commit message.

=item fetch

Fetches from each repository's remote repository, but does not
update the working copy. Only supported for some distributed version
control systems.

=item push

Pushes committed local changes to the remote repository. A no-op for
centralized version control systems.

=item diff

Show a diff of uncommitted changes.

=item log

Show the commit log.

=item grep pattern

Searches for a pattern in each repository using the grep subcommand. Uses
ack-grep on VCS that do not have their own.

=item run command [param ...]

Runs the specified command in each repository.

=back

These commands are also available:

=over 4

=item bootstrap src [directory]

Causes mr to retrieve the source C<src> and use it as a .mrconfig file to
checkout the repositories listed in it, into the specified directory.

B<mr> understands several types of sources:

=over 4

=item URL for curl

C<src> may be an URL understood by B<curl>.

=item copy via ssh

To use B<scp> to download, the C<src> may have the form
C<ssh://[user@]host:file>.

=item local file

You can retrieve the config file by other means and pass its B<path> as C<src>.

=item standard input

If source C<src> consists in a single dash C<->, config file is read from
standard input.

=back

The directory will be created if it does not exist. If no directory is
specified, the current directory will be used.

As a special case, if source C<src> includes a repository named ".", that
is checked out into the top of the specified directory.

=item list (or ls)

List the repositories that mr will act on.

=item register

Register an existing repository in a mrconfig file. By default, the
repository in the current directory is registered, or you can specify a
directory to register.

The mrconfig file that is modified is chosen by either the -c option, or by
looking for the closest known one at or in a parent of the current directory.

=item config

Adds, modifies, removes, or prints a value from a mrconfig file. The next
parameter is the name of the section the value is in. To add or modify
values, use one or more instances of "setting=value". Use "setting=" to
remove a setting. Use just "setting" to get the value of a that setting.

For example, to add (or edit) a repository in src/foo:

  mr config src/foo checkout="svn co svn://example.com/foo/trunk foo"

To show the command that mr uses to update the repository in src/foo:

  mr config src/foo update

To see the built-in library of shell functions contained in mr:

  mr config DEFAULT lib

The mrconfig file that is used is chosen by either the -c option, or by
looking for the closest known one at or in a parent of the current directory.

=item offline

Advises mr that it is in offline mode. Any commands that fail in
offline mode will be remembered, and retried when mr is told it's online.

=item online

Advices mr that it is in online mode again. Commands that failed while in
offline mode will be re-run.

=item remember

Remember a command, to be run later when mr re-enters online mode. This
implicitly puts mr into offline mode. The command can be any regular mr
command. This is useful when you know that a command will fail due to being
offline, and so don't want to run it right now at all, but just remember
to run it when you go back online.

=item help

Displays this help.

=back

Actions can be abbreviated to any unambiguous substring, so
"mr st" is equivalent to "mr status", and "mr up" is equivalent to "mr
update"

Additional parameters can be passed to most commands, and are passed on
unchanged to the underlying version control system. This is mostly useful
if the repositories mr will act on all use the same version control
system.

=head1 OPTIONS

=over 4

=item -d directory

=item --directory directory

Specifies the topmost directory that B<mr> should work in. The default is
the current working directory.

=item -c mrconfig

=item --config mrconfig

Use the specified mrconfig file. The default is to use both F<~/.mrconfig>
as well as look for a F<.mrconfig> file in the current directory, or in one
of its parent directories.

=item -f

=item --force

Force mr to act on repositories that would normally be skipped due to their
configuration.

=item -v

=item --verbose

Be verbose.

=item -m

=item --minimal

Minimise output. If a command fails or there is any output then the usual
output will be shown.

=item -q

=item --quiet

Be quiet. This suppresses mr's usual output, as well as any output from
commands that are run (including stderr output). If a command fails,
the output will be shown.

=item -k

=item --insecure

Accept untrusted SSL certificates when bootstrapping.

=item -s

=item --stats

Expand the statistics line displayed at the end to include information
about exactly which repositories failed and were skipped, if any.

=item -i

=item --interactive

Interactive mode. If a repository fails to be processed, a subshell will be
started which you can use to resolve or investigate the problem. Exit the
subshell to continue the mr run.

=item -n [number]

=item --no-recurse [number]

If no number if specified, just operate on the repository for the current
directory, do not recurse into deeper repositories.

If a number is specified, will recurse into repositories at most that many
subdirectories deep. For example, with -n 2 it would recurse into ./src/foo,
but not ./src/packages/bar.

=item -j [number]

=item --jobs [number]

Run the specified number of jobs in parallel, or an unlimited number of jobs
with no number specified. This can greatly speed up operations such as updates.
It is not recommended for interactive operations.

Note that running more than 10 jobs at a time is likely to run afoul of
ssh connection limits. Running between 3 and 5 jobs at a time will yield
a good speedup in updates without loading the machine too much.

=item -t

=item --trust-all

Trust all mrconfig files even if they are not listed in F<~/.mrtrust>.
Use with caution.

=item -p

=item --path

This obsolete flag is ignored.

=back

=head1 MRCONFIG FILES

Here is an example F<.mrconfig> file:

  [src]
  checkout = svn checkout svn://svn.example.com/src/trunk src
  chain = true

  [src/linux-2.6]
  checkout = git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git &&
        cd linux-2.6 &&
        git checkout -b mybranch origin/master

The F<.mrconfig> file uses a variant of the INI file format. Lines
starting with "#" are comments. Values can be continued to the
following line by indenting the line with whitespace.

The C<DEFAULT> section allows setting default values for the sections that
come after it.

The C<ALIAS> section allows adding aliases for actions. Each setting
is an alias, and its value is the action to use.

All other sections add repositories. The section header specifies the
directory where the repository is located. This is relative to the directory
that contains the mrconfig file, but you can also choose to use absolute
paths. (Note that you can use environment variables in section names; they
will be passed through the shell for expansion. For example, 
C<[$HOSTNAME]>, or C<[${HOSTNAME}foo]>).

Within a section, each setting defines a shell command to run to handle a
given action. mr contains default handlers for "update", "status",
"commit", and other standard actions.

Normally you only need to specify what to do for "checkout". Here you
specify the command to run in order to create a checkout of the repository.
The command will be run in the parent directory, and must create the
repository's directory. So use C<git clone>, C<svn checkout>, C<bzr branch>
or C<bzr checkout> (for a bound branch), etc.

Note that these shell commands are run in a C<set -e> shell
environment, where any additional parameters you pass are available in
C<$@>. All commands other than "checkout" are run inside the repository,
though not necessarily at the top of it.

The C<MR_REPO> environment variable is set to the path to the top of the
repository. (For the "register" action, "MR_REPO" is instead set to the 
basename of the directory that should be created when checking the
repository out.)

The C<MR_CONFIG> environment variable is set to the .mrconfig file
that defines the repo being acted on, or, if the repo is not yet in a config
file, the F<.mrconfig> file that should be modified to register the repo.

The C<MR_ACTION> environment variable is set to the command being run
(update, checkout, etc).

A few settings have special meanings:

=over 4

=item skip

If "skip" is set and its command returns true, then B<mr>
will skip acting on that repository. The command is passed the action
name in C<$1>.

Here are two examples. The first skips the repo unless
mr is run by joey. The second uses the hours_since function
(included in mr's built-in library) to skip updating the repo unless it's
been at least 12 hours since the last update.

  [mystuff]
  checkout = ...
  skip = test `whoami` != joey

  [linux]
  checkout = ...
  skip = [ "$1" = update ] && ! hours_since "$1" 12
 
Another way to use skip is for a lazy checkout. This makes mr skip
operating on a repo unless it already exists. To enable the 
repo, you have to explicitly check it out (using "mr --force -d foo checkout").

  [foo]
  checkout = ...
  skip = lazy

=item order

The "order" setting can be used to override the default ordering of
repositories. The default order value is 10. Use smaller values to make
repositories be processed earlier, and larger values to make repositories
be processed later.

Note that if a repository is located in a subdirectory of another
repository, ordering it to be processed earlier is not recommended.

=item chain

If "chain" is set and its command returns true, then B<mr>
will try to load a F<.mrconfig> file from the root of the repository.

=item include

If "include" is set, its command is ran, and should output
additional mrconfig file content. The content is included as if it were
part of the including file.

Unlike everything else, "include" does not need to be placed within a section.

B<mr> ships several libraries that can be included to add support for
additional version control type things (unison, git-svn, git-fake-bare,
git-subtree). To include them all, you could use:

  include = cat /usr/share/mr/*

See the individual files for details.

=item deleted

If "deleted" is set and its command returns true, then
B<mr> will treat the repository as deleted. It won't ever actually delete
the repository, but it will warn if it sees the repository's directory.
This is useful when one mrconfig file is shared among multiple machines,
to keep track of and remember to delete old repositories.

=item lib

The "lib" setting can contain some shell code that will be run
before each command, this can be a useful way to define shell
functions for other commands to use. 

Unlike most other settings, this can be specified multiple times, in
which case the chunks of shell code are accumulatively concatenated
together.

=item fixups

If "fixups" is set, its command is run whenever a repository
is checked out, or updated. This provides an easy way to do things
like permissions fixups, or other tweaks to the repository content,
whenever the repository is changed.

=item VCS_action

When looking for a command to run for a given action, mr first looks for
a setting with the same name as the action. If that is not found, it
looks for a setting named "VCS_action" (substituting in the name of the
version control system and the action).

Internally, mr has settings for "git_update", "svn_update", etc. To change
the action that is performed for a given version control system, you can
override these VCS specific actions. To add a new version control system,
you can just add VCS specific actions for it.

=item pre_ and post_

If "pre_action" is set, its command is run before mr performs the
specified action. Similarly, "post_action" commands are run after mr
successfully performs the specified action. For example, "pre_commit" is
run before committing; "post_update" is run after updating.

=item _append

Any setting can be suffixed with C<_append>, to add an additional value
to the existing value of the setting. In this way, actions 
can be constructed accumulatively.

=item VCS_test

The name of the version control system is itself determined by
running each defined "VCS_test" action, until one succeeds.

=back

=head1 UNTRUSTED MRCONFIG FILES

Since mrconfig files can contain arbitrary shell commands, they can do
anything. This flexibility is good, but it also allows a malicious mrconfig
file to delete your whole home directory. Such a file might be contained
inside a repository that your main F<~/.mrconfig> checks out. To
avoid worries about evil commands in a mrconfig file, mr defaults to
reading all mrconfig files other than the main F<~/.mrconfig> in untrusted
mode. In untrusted mode, mrconfig files are limited to running only known
safe commands (like "git clone") in a carefully checked manner.

To configure mr to trust other mrconfig files, list them in F<~/.mrtrust>.
One mrconfig file should be listed per line. Either the full pathname
should be listed, or the pathname can start with F<~/> to specify a file
relative to your home directory.

=head1 OFFLINE LOG FILE

The F<~/.mrlog> file contains commands that mr has remembered to run later,
due to being offline. You can delete or edit this file to remove commands,
or even to add other commands for 'mr online' to run. If the file is
present, mr assumes it is in offline mode.

=head1 EXTENSIONS

mr can be extended to support things such as unison and git-svn. Some
files providing such extensions are available in F</usr/share/mr/>. See
the documentation in the files for details about using them.

=head1 EXIT STATUS

mr returns nonzero if a command failed in any of the repositories.

=head1 AUTHOR

Copyright 2007-2011 Joey Hess <joey@kitenet.net>

Licensed under the GNU GPL version 2 or higher.

http://myrepos.branchable.com/

=cut

use warnings;
use strict;
use Getopt::Long;
use Cwd qw(getcwd abs_path);

# things that can happen when mr runs a command
use constant {
        OK => 0,
        FAILED => 1,
        SKIPPED => 2,
        ABORT => 3,
};

# configurables
my $config_overridden=0;
my $verbose=0;
my $minimal=0;
my $quiet=0;
my $stats=0;
my $force=0;
my $insecure=0;
my $interactive=0;
my $max_depth;
my $no_chdir=0;
my $jobs=1;
my $trust_all=0;
my $directory=getcwd();
my $terminal=-t STDOUT && eval{require IO::Pty::Easy;IO::Pty::Easy->import();1;};

my $HOME_MR_CONFIG = "$ENV{HOME}/.mrconfig";
$ENV{MR_CONFIG}=find_mrconfig();

# globals :-(
my %config;
my %configfiles;
my %knownactions;
my %alias;
my (@ok, @failed, @skipped);

main();

sub shellquote {
        my $i=shift;
        $i=~s/'/'"'"'/g;
        return "'$i'";
}

# Runs a shell command using a supplied function.
# The lib will be included in the shell command line, and any params
# will be available in the shell as $1, $2, etc.
my $lastlib;
sub runsh {
        my ($action, $topdir, $subdir, $command, $params, $runner) = @_;

        # optimisation: avoid running the shell for true and false
        if ($command =~ /^\s*true\s*$/) {
                $?=0;
                return 0;
        }
        elsif ($command =~ /^\s*false\s*$/) {
                $?=0;
                return 1;
        }
        
        my $quotedparams=join(" ", (map { shellquote($_) } @$params));
        my $lib=exists $config{$topdir}{$subdir}{lib} ?
                       $config{$topdir}{$subdir}{lib}."\n" : "";
        if ($verbose && (! defined $lastlib || $lastlib ne $lib)) {
                print "mr library now: >>$lib<<\n";
                $lastlib=$lib;
        }
        my $shellcode="set -e;".$lib.
                "my_sh(){ $command\n }; my_sh $quotedparams";
        print "mr $action: running $action >>$command<<\n" if $verbose;
        $runner->($shellcode);
}

my %perl_cache;
sub perl {
        my $id=shift;
        my $s=shift;
        if ($s =~ m/^perl:\s+(.*)/s) {
                return $perl_cache{$1} if exists $perl_cache{$1};
                my $sub=eval "sub {$1}";
                if (! defined $sub) {
                        print STDERR "mr: bad perl code in $id: $@\n";
                }
                return $perl_cache{$1} = $sub;
        }
        return undef;
}

my %vcs;
sub vcs_test {
        my ($action, $dir, $topdir, $subdir) = @_;

        if (exists $vcs{$dir}) {
                return $vcs{$dir};
        }

        my $test="";
        my %perltest;
        foreach my $vcs_test (
                        sort {
                                length $a <=> length $b 
                                          ||
                                       $a cmp $b
                        } grep { /_test$/ } keys %{$config{$topdir}{$subdir}}) {
                my ($vcs)=$vcs_test =~ /(.*)_test/;
                my $p=perl($vcs_test, $config{$topdir}{$subdir}{$vcs_test});
                if (defined $p) {
                        $perltest{$vcs}=$p;
                }
                else {
                        $test="my_$vcs_test() {\n$config{$topdir}{$subdir}{$vcs_test}\n}\n".$test;
                        $test.="if my_$vcs_test; then echo $vcs; fi\n";
                }
        }

        my @vcs;
        foreach my $vcs (keys %perltest) {
                if ($perltest{$vcs}->()) {
                        push @vcs, $vcs;
                }
        }

        push @vcs, split(/\n/,
                runsh("vcs test", $topdir, $subdir, $test, [], sub {
                        my $sh=shift;
                        my $ret=`$sh`;
                        return $ret;
                })) if length $test;
        if (@vcs > 1) {
                print STDERR "mr $action: found multiple possible repository types (@vcs) for ".fulldir($topdir, $subdir)."\n";
                return undef;
        }
        if (! @vcs) {
                return $vcs{$dir}=undef;
        }
        else {
                return $vcs{$dir}=$vcs[0];
        }
}
        
sub findcommand {
        my ($action, $dir, $topdir, $subdir, $is_checkout) = @_;
        
        if (exists $config{$topdir}{$subdir}{$action}) {
                return $config{$topdir}{$subdir}{$action};
        }

        if ($is_checkout) {
                return undef;
        }

        my $vcs=vcs_test(@_);

        if (defined $vcs && 
            exists $config{$topdir}{$subdir}{$vcs."_".$action}) {
                return $config{$topdir}{$subdir}{$vcs."_".$action};
        }
        else {
                return undef;
        }
}

sub fulldir {
        my ($topdir, $subdir) = @_;
        return $subdir =~ /^\// ? $subdir : $topdir.$subdir;
}

sub terminal_friendly_spawn {
        my $actionmsg = shift;
        my $sh = shift;
        my $quiet = shift;
        my $minimal = shift;
        my $output = "";
        if ($terminal) {
                my $pty = IO::Pty::Easy->new;
                $pty->spawn($sh);
                while ($pty->is_active) {
                        my $data = $pty->read();
                        $output .= $data if defined $data;
                }
                $pty->close;
        } else {
                $output = qx/$sh 2>&1/;
        }
        my $ret = $?;
        if ($quiet && $ret != 0) {
                print "$actionmsg\n" if $actionmsg;
                print STDERR $output;
        } elsif (!$quiet && (!$minimal || $output)) {
                print "$actionmsg\n" if $actionmsg;
                print $output;
        }
        return ($ret, $output ? 1 : 0);
}

sub action {
        my ($action, $dir, $topdir, $subdir, $force_checkout) = @_;
        my $fulldir=fulldir($topdir, $subdir);
        my $checkout_dir;

        $ENV{MR_CONFIG}=$configfiles{$topdir};
        my $is_checkout=($action eq 'checkout');
        my $is_update=($action =~ /update/);

        ($ENV{MR_REPO}=$dir) =~ s!/$!!;
        $ENV{MR_ACTION}=$action;
        
        foreach my $testname ("skip", "deleted") {
                next if $force && $testname eq "skip";

                my $testcommand=findcommand($testname, $dir, $topdir, $subdir, $is_checkout);

                if (defined $testcommand) {
                        my $ret=runsh "$testname test", $topdir, $subdir,
                                $testcommand, [$action],
                                sub { system(shift()) };
                        if ($ret != 0) {
                                if (($? & 127) == 2) {
                                        print STDERR "mr $action: interrupted\n";
                                        return ABORT;
                                }
                                elsif ($? & 127) {
                                        print STDERR "mr $action: $testname test received signal ".($? & 127)."\n";
                                        return ABORT;
                                }
                        }
                        if ($ret >> 8 == 0) {
                                if ($testname eq "deleted") {
                                        if (-d $dir) {
                                                print STDERR "mr error: $dir should be deleted yet still exists\n";
                                                return FAILED;
                                        }
                                }
                                print "mr $action: skip $dir skipped\n" if $verbose;
                                return SKIPPED;
                        }
                }
        }

        if ($is_checkout) {
                $checkout_dir=$dir;
                if (! $force_checkout) {
                        if (-d $dir) {
                                print "mr $action: $dir already exists, skipping checkout\n" if $verbose;
                                return SKIPPED;
                        }
        
                        $dir=~s/^(.*)\/[^\/]+\/?$/$1/;
                }
        }
        elsif ($is_update) {
                if (! -d $dir) {
                        return action("checkout", $dir, $topdir, $subdir);
                }
        }

        my $command=findcommand($action, $dir, $topdir, $subdir, $is_checkout);

        if ($is_checkout && ! -d $dir) {
                print "mr $action: creating parent directory $dir\n" if $verbose;
                system("mkdir", "-p", $dir);
        }

        if (! $no_chdir && ! chdir($dir)) {
                print STDERR "mr $action: failed to chdir to $dir: $!\n";
                return FAILED;
        }
        elsif (! defined $command) {
                my $vcs=vcs_test(@_);
                if (! defined $vcs) {
                        print STDERR "mr $action: unknown repository type and no defined $action command for $fulldir\n";
                        return FAILED;
                }
                else {
                        print STDERR "mr $action: no defined action for $vcs repository $fulldir, skipping\n" unless $minimal;
                        return SKIPPED;
                }
        }
        else {
                my $actionmsg;
                if (! $no_chdir) {
                        $actionmsg="mr $action: $fulldir";
                }
                else {
                        my $s=$directory;
                        $s=~s/^\Q$fulldir\E\/?//;
                        $actionmsg="mr $action: $fulldir (in subdir $s)";
                }
                print "$actionmsg\n" unless $quiet || $minimal;

                my ($hookret, $hook_out)=hook("pre_$action", $topdir, $subdir);
                return $hookret if $hookret != OK;

                my ($ret, $out)=runsh $action, $topdir, $subdir,
                        $command, \@ARGV, sub {
                                my $sh=shift;
                                if (!$jobs || $jobs > 1 || $quiet || $minimal) {
                                        return terminal_friendly_spawn($actionmsg, $sh, $quiet, $minimal);
                                }
                                else {
                                        system($sh);
                                }
                        };
                if ($ret != 0) {
                        if (($? & 127) == 2) {
                                print STDERR "mr $action: interrupted\n";
                                return ABORT;
                        }
                        elsif ($? & 127) {
                                print STDERR "mr $action: received signal ".($? & 127)."\n";
                                return ABORT;
                        }
                        print STDERR "mr $action: failed ($ret)\n" if $verbose;
                        if ($ret >> 8 != 0) {
                                print STDERR "mr $action: command failed\n";
                                if (-e "$ENV{HOME}/.mrlog" && $action ne 'remember') {
                                        # recreate original command line to
                                        # remember, and avoid recursing
                                        my @orig=@ARGV;
                                        @ARGV=('-n', $action, @orig);
                                        action("remember", $dir, $topdir, $subdir);
                                        @ARGV=@orig;
                                }
                        }
                        elsif ($ret != 0) {
                                print STDERR "mr $action: command died ($ret)\n";
                        }
                        return FAILED;
                }
                else {
                        if ($is_checkout && ! -d $dir) {
                                print STDERR "mr $action: $dir missing after checkout\n";;
                                return FAILED;
                        }

                        my ($ret, $hook_out)=hook("post_$action", $topdir, $subdir);
                        return $ret if $ret != OK;
                        
                        if ($is_checkout || $is_update) {
                                if ($is_checkout && ! $no_chdir) {
                                        if (! chdir($checkout_dir)) {
                                                print STDERR "mr $action: failed to chdir to $checkout_dir: $!\n";
                                                return FAILED;
                                        }
                                }
                                my ($ret, $hook_out)=hook("fixups", $topdir, $subdir);
                                return $ret if $ret != OK;
                        }
                        
                        return (OK, $out || $hook_out);
                }
        }
}

sub hook {
        my ($hook, $topdir, $subdir) = @_;

        my $command=$config{$topdir}{$subdir}{$hook};
        return OK unless defined $command;
        my ($ret,$out)=runsh $hook, $topdir, $subdir, $command, [], sub {
                        my $sh=shift;
                        if (!$jobs || $jobs > 1 || $quiet || $minimal) {
                                return terminal_friendly_spawn(undef, $sh, $quiet, $minimal);
                        }
                        else {
                                system($sh);
                        }
                };
        if ($ret != 0) {
                if (($? & 127) == 2) {
                        print STDERR "mr $hook: interrupted\n";
                        return ABORT;
                }
                elsif ($? & 127) {
                        print STDERR "mr $hook: received signal ".($? & 127)."\n";
                        return ABORT;
                }
                else {
                        return FAILED;
                }
        }

        return (OK, $out);
}

# run actions on multiple repos, in parallel
sub mrs {
        my $action=shift;
        my @repos=@_;

        $| = 1;
        my @active;
        my @fhs;
        my @out;
        my $running=0;
        while (@fhs or @repos) {
                while ((!$jobs || $running < $jobs) && @repos) {
                        $running++;
                        my $repo = shift @repos;
                        pipe(my $outfh, CHILD_STDOUT);
                        pipe(my $errfh, CHILD_STDERR);
                        my $pid;
                        unless ($pid = fork) {
                                die "mr $action: cannot fork: $!" unless defined $pid;
                                open(STDOUT, ">&CHILD_STDOUT") || die "mr $action cannot reopen stdout: $!";
                                open(STDERR, ">&CHILD_STDERR") || die "mr $action cannot reopen stderr: $!";
                                close CHILD_STDOUT;
                                close CHILD_STDERR;
                                close $outfh;
                                close $errfh;
                                exit +(action($action, @$repo))[0];
                        }
                        close CHILD_STDOUT;
                        close CHILD_STDERR;
                        push @active, [$pid, $repo];
                        push @fhs, [$outfh, $errfh];
                        push @out, ['',     ''];
                }
                my ($rin, $rout) = ('','');
                my $nfound;
                foreach my $fh (@fhs) {
                        next unless defined $fh;
                        vec($rin, fileno($fh->[0]), 1) = 1 if defined $fh->[0];
                        vec($rin, fileno($fh->[1]), 1) = 1 if defined $fh->[1];
                }
                $nfound = select($rout=$rin, undef, undef, 1);
                foreach my $channel (0, 1) {
                        foreach my $i (0..$#fhs) {
                                next unless defined $fhs[$i];
                                my $fh = $fhs[$i][$channel];
                                next unless defined $fh;
                                if (vec($rout, fileno($fh), 1) == 1) {
                                        my $r = '';
                                        if (sysread($fh, $r, 1024) == 0) {
                                                close($fh);
                                                $fhs[$i][$channel] = undef;
                                                if (! defined $fhs[$i][0] &&
                                                    ! defined $fhs[$i][1]) {
                                                        waitpid($active[$i][0], 0);
                                                        print STDOUT $out[$i][0];
                                                        print STDERR $out[$i][1];
                                                        record($active[$i][1], $? >> 8, $out[$i][0] || $out[$i][1]);
                                                        splice(@fhs, $i, 1);
                                                        splice(@active, $i, 1);
                                                        splice(@out, $i, 1);
                                                        $running--;
                                                }
                                        }
                                        $out[$i][$channel] .= $r;
                                }
                        }
                }
        }
}

sub record {
        my $dir=shift()->[0];
        my $ret=shift;
        my $out=shift;

        if ($ret == OK) {
                push @ok, $dir;
                print "\n" unless $quiet || ($minimal && !$out);
        }
        elsif ($ret == FAILED) {
                if ($interactive) {
                        chdir($dir) unless $no_chdir;
                        print STDERR "mr: Starting interactive shell. Exit shell to continue.\n";
                        system((getpwuid($<))[8], "-i");
                }
                push @failed, $dir;
                print "\n";
        }
        elsif ($ret == SKIPPED) {
                push @skipped, $dir;
        }
        elsif ($ret == ABORT) {
                exit 1;
        }
        else {
                die "unknown exit status $ret";
        }
}

sub showstats {
        my $action=shift;
        if (! @ok && ! @failed && ! @skipped) {
                die "mr $action: no repositories found to work on\n";
        }
        print "mr $action: finished (".join("; ",
                showstat($#ok+1, "ok", "ok"),
                showstat($#failed+1, "failed", "failed"),
                showstat($#skipped+1, "skipped", "skipped"),
        ).")\n" unless $quiet || $minimal;
        if ($stats) {
                if (@skipped) {
                        print "mr $action: (skipped: ".join(" ", @skipped).")\n" unless $quiet || $minimal;
                }
                if (@failed) {
                        print STDERR "mr $action: (failed: ".join(" ", @failed).")\n";
                }
        }
}

sub showstat {
        my $count=shift;
        my $singular=shift;
        my $plural=shift;
        if ($count) {
                return "$count ".($count > 1 ? $plural : $singular);
        }
        return;
}

# an ordered list of repos
sub repolist {
        my @list;
        foreach my $topdir (sort keys %config) {
                foreach my $subdir (sort keys %{$config{$topdir}}) {
                        push @list, {
                                topdir => $topdir,
                                subdir => $subdir,
                                order => $config{$topdir}{$subdir}{order},
                        };
                }
        }
        return sort {
                $a->{order}  <=> $b->{order}
                             ||
                $a->{topdir} cmp $b->{topdir}
                             ||
                $a->{subdir} cmp $b->{subdir}
        } @list;
}

sub repodir {
        my $repo=shift;
        my $topdir=$repo->{topdir};
        my $subdir=$repo->{subdir};
        my $ret=($subdir =~/^\//) ? $subdir : $topdir.$subdir;
        $ret=~s/\/\.$//;
        return $ret;
}

# Figure out which repos to act on.  Returns a list of array refs
# in the format:
#
#   [ "$full_repo_path/", "$mr_config_path/", $section_header ]
sub selectrepos {
        my @repos;
        foreach my $repo (repolist()) {
                my $topdir=$repo->{topdir};
                my $subdir=$repo->{subdir};

                next if $subdir eq 'DEFAULT';
                my $dir=repodir($repo);
                my $d=$directory;
                $dir.="/" unless $dir=~/\/$/;
                $d.="/" unless $d=~/\/$/;
                next if $dir ne $d && $dir !~ /^\Q$d\E/;
                if (defined $max_depth) {
                        my @a=split('/', $dir);
                        my @b=split('/', $d);
                        do { } while (@a && @b && shift(@a) eq shift(@b));
                        next if @a > $max_depth || @b > $max_depth;
                }
                push @repos, [$dir, $topdir, $subdir];
        }
        if (! @repos) {
                # fallback to find a leaf repo
                foreach my $repo (reverse repolist()) {
                        my $topdir=$repo->{topdir};
                        my $subdir=$repo->{subdir};
                        
                        next if $subdir eq 'DEFAULT';
                        my $dir=repodir($repo);
                        my $d=$directory;
                        $dir.="/" unless $dir=~/\/$/;
                        $d.="/" unless $d=~/\/$/;
                        if ($d=~/^\Q$dir\E/) {
                                push @repos, [$dir, $topdir, $subdir];
                                last;
                        }
                }
                $no_chdir=1;
        }
        return @repos;
}

sub expandenv {
        my $val=shift;
        

        if ($val=~/\$/) {
                $val=`echo "$val"`;
                chomp $val;
        }
        
        return $val;
}

my %trusted;
sub is_trusted_config {
        my $config=shift; # must be abs_pathed already

        # We always trust ~/.mrconfig.
        return 1 if $config eq abs_path($HOME_MR_CONFIG);

        return 1 if $trust_all;

        my $trustfile=$ENV{HOME}."/.mrtrust";

        if (! %trusted) {
                $trusted{$HOME_MR_CONFIG}=1;
                if (open (TRUST, "<", $trustfile)) {
                        while (<TRUST>) {
                                chomp;
                                s/^~\//$ENV{HOME}\//;
                                my $d=abs_path($_);
                                $trusted{$d}=1 if defined $d;
                        }
                        close TRUST;
                }
        }

        return $trusted{$config};
}


sub is_trusted_repo {
        my $repo=shift;
        
        # Tightly limit what is allowed in a repo name.
        # No ../, no absolute paths, and no unusual filenames
        # that might try to escape to the shell.
        return $repo =~ /^[-_.+\/A-Za-z0-9]+$/ &&
               $repo !~ /\.\./ && $repo !~ /^\//;
}

sub is_trusted_checkout {
        my $command=shift;
        
        # To determine if the command is safe, compare it with the
        # *_trusted_checkout config settings. Those settings are
        # templates for allowed commands, so make sure that each word
        # of the command matches the corresponding word of the template.
        
        my @words;
        foreach my $word (split(' ', $command)) {
                # strip quoting
                if ($word=~/^'(.*)'$/) {
                        $word=$1;
                }
                elsif ($word=~/^"(.*)"$/) {
                        $word=$1;
                }

                push @words, $word;
        }

        foreach my $key (grep { /_trusted_checkout$/ }
                         keys %{$config{''}{DEFAULT}}) {
                my @twords=split(' ', $config{''}{DEFAULT}{$key});
                next if @words > @twords;

                my $match=1;
                my $url;
                for (my $c=0; $c < @twords && $match; $c++) {
                        if ($twords[$c] eq '$url') {
                                # Match all the typical characters found in
                                # urls, plus @ which svn can use. Note
                                # that the "url" might also be a local
                                # directory.
                                $match=(
                                        defined $words[$c] &&
                                        $words[$c] =~ /^[-_.+:@\/A-Za-z0-9]+$/
                                );
                                $url=$words[$c];
                        }
                        elsif ($twords[$c] eq '$repo') {
                                # If a repo is not specified, assume it
                                # will be the last path component of the
                                # url, or something derived from it, and
                                # check that.
                                if (! defined $words[$c] && defined $url) {
                                        ($words[$c])=$url=~/\/([^\/]+)\/?$/;
                                }

                                $match=(
                                        defined $words[$c] &&
                                        is_trusted_repo($words[$c])
                                );
                        }
                        elsif (defined $words[$c] && $words[$c]=~/^($twords[$c])$/) {
                                $match=1;
                        }
                        else {
                                $match=0;
                        }
                }
                return 1 if $match;
        }

        return 0;
}

my %loaded;
sub loadconfig {
        my $f=shift;
        my $dir=shift;
        my $bootstrap_src=shift;

        my @toload;

        my $in;
        my $trusted;
        if (ref $f eq 'GLOB') {
                $dir="";
                $in=$f;
                $trusted=1;
        }
        else {
                my $absf=abs_path($f);
                if ($loaded{$absf}) {
                        return;
                }
                $loaded{$absf}=1;

                $trusted=is_trusted_config($absf);

                if (! defined $dir) {
                        ($dir)=$f=~/^(.*\/)[^\/]+$/;
                        if (! defined $dir) {
                                $dir=".";
                        }
                }

                $dir=abs_path($dir)."/";
                
                if (! exists $configfiles{$dir}) {
                        $configfiles{$dir}=$f;
                }

                # copy in defaults from first parent
                my $parent=$dir;
                while ($parent=~s/^(.*\/)[^\/]+\/?$/$1/) {
                        if ($parent eq '/') {
                                $parent="";
                        }
                        if (exists $config{$parent} &&
                            exists $config{$parent}{DEFAULT}) {
                                $config{$dir}{DEFAULT}={ %{$config{$parent}{DEFAULT}} };
                                last;
                        }
                }
                
                if (! -e $f) {
                        return;
                }

                print "mr: loading config $f\n" if $verbose;
                open($in, "<", $f) || die "mr: open $f: $!\n";
        }
        my @lines=<$in>;
        close $in unless ref $f eq 'GLOB';

        my $section;

        # Keep track of the current line in the config file;
        # when a file is included track the current line from the include.
        my $lineno=0;
        my $included=undef;

        my $line;
        my $nextline = sub {
                if ($included) {
                        $included--;
                }
                else {
                        $included=undef;
                        $lineno++;
                }
                $line=shift @lines;
                chomp $line;
                return $line;
        };
        my $lineerror = sub {
                my $msg=shift;
                if (defined $included) {
                        die "mr: $msg at $f line $lineno, included line: $line\n";
                }
                else {
                        die "mr: $msg at $f line $lineno\n";
                }
        };
        my $trusterror = sub {
                my $msg=shift;
        
                if (defined $bootstrap_src) {
                        die "mr: $msg in untrusted $bootstrap_src line $lineno\n".
                                "(To trust this url, --trust-all can be used; but please use caution;\n".
                                "this can allow arbitrary code execution!)\n";
                }
                else {
                        die "mr: $msg in untrusted $f line $lineno\n".
                                "(To trust this file, list it in ~/.mrtrust.)\n";
                }
        };

        while (@lines) {
                $_=$nextline->();

                next if /^\s*\#/ || /^\s*$/;

                if (! $trusted && /[[:cntrl:]]/) {
                        $trusterror->("illegal control character");
                }

                if (/^\[([^\]]*)\]\s*$/) {
                        $section=$1;

                        if (! $trusted) {
                                if (! is_trusted_repo($section) ||
                                    $section eq 'ALIAS' ||
                                    $section eq 'DEFAULT') {
                                        $trusterror->("illegal section \"[$section]\"");
                                }
                        }
                        $section=expandenv($section) if $trusted;
                        if ($section ne 'ALIAS' &&
                            ! exists $config{$dir}{$section} &&
                            exists $config{$dir}{DEFAULT}) {
                                # copy in defaults
                                $config{$dir}{$section}={ %{$config{$dir}{DEFAULT}} };
                        }
                }
                elsif (/^(\w+)\s*=\s*(.*)/) {
                        my $parameter=$1;
                        my $value=$2;

                        # continued value
                        while (@lines && $lines[0]=~/^\s(.+)/) {
                                $value.="\n$1";
                                chomp $value;
                                $nextline->();
                        }

                        if (! $trusted) {
                                # Untrusted files can only contain a few
                                # settings in specific known-safe formats.
                                if ($parameter eq 'checkout') {
                                        if (! is_trusted_checkout($value)) {
                                                $trusterror->("illegal checkout command \"$value\"");
                                        }
                                }
                                elsif ($parameter eq 'order') {
                                        # not interpreted as a command, so
                                        # safe.
                                }
                                elsif ($value eq 'true' || $value eq 'false') {
                                        # skip=true , deleted=true etc are
                                        # safe.
                                }
                                else {
                                        $trusterror->("illegal setting \"$parameter=$value\"");
                                }
                        }

                        if ($parameter eq "include") {
                                print "mr: including output of \"$value\"\n" if $verbose;
                                my @inc=`$value`;
                                if ($?) {
                                        print STDERR "mr: include command exited nonzero ($?)\n";
                                }
                                $included += @inc;
                                unshift @lines, @inc;
                                next;
                        }

                        if (! defined $section) {
                                $lineerror->("parameter ($parameter) not in section");
                        }
                        if ($section eq 'ALIAS') {
                                $alias{$parameter}=$value;
                        }
                        elsif ($parameter eq 'lib' or $parameter =~ s/_append$//) {
                                $config{$dir}{$section}{$parameter}.="\n".$value."\n";
                        }
                        else {
                                $config{$dir}{$section}{$parameter}=$value;
                                if ($parameter =~ /.*_(.*)/) {
                                        $knownactions{$1}=1;
                                }
                                else {
                                        $knownactions{$parameter}=1;
                                }
                                if ($parameter eq 'chain' &&
                                    length $dir && $section ne "DEFAULT") {
                                        my $chaindir="$section";
                                        if ($chaindir !~ m!^/!) {
                                                $chaindir=$dir.$chaindir;
                                        }
                                        if (-e "$chaindir/.mrconfig") {
                                                my $ret=system($value);
                                                if ($ret != 0) {
                                                        if (($? & 127) == 2) {
                                                                print STDERR "mr: chain test interrupted\n";
                                                                exit 2;
                                                        }
                                                        elsif ($? & 127) {
                                                                print STDERR "mr: chain test received signal ".($? & 127)."\n";
                                                        }
                                                }
                                                else {
                                                        push @toload, ["$chaindir/.mrconfig", $chaindir];
                                                }
                                        }
                                }
                        }
                }
                else {
                        $lineerror->("parse error");
                }
        }

        foreach my $c (@toload) {
                loadconfig(@$c);
        }
}

sub startingconfig {
        %alias=%config=%configfiles=%knownactions=%loaded=();
        my $datapos=tell(DATA);
        loadconfig(\*DATA);
        seek(DATA,$datapos,0); # rewind
}

sub modifyconfig {
        my $f=shift;
        # the section to modify or add
        my $targetsection=shift;
        # fields to change in the section
        # To remove a field, set its value to "".
        my %changefields=@_;

        my @lines;
        my @out;

        if (-e $f) {
                open(my $in, "<", $f) || die "mr: open $f: $!\n";
                @lines=<$in>;
                close $in;
        }

        my $formatfield=sub {
                my $field=shift;
                my @value=split(/\n/, shift);

                return "$field = ".shift(@value)."\n".
                        join("", map { "\t$_\n" } @value);
        };
        my $addfields=sub {
                my @blanks;
                while ($out[$#out] =~ /^\s*$/) {
                        unshift @blanks, pop @out;
                }
                foreach my $field (sort keys %changefields) {
                        if (length $changefields{$field}) {
                                push @out, "$field = $changefields{$field}\n";
                                delete $changefields{$field};
                        }
                }
                push @out, @blanks;
        };

        my $section;
        while (@lines) {
                $_=shift(@lines);

                if (/^\s*\#/ || /^\s*$/) {
                        push @out, $_;
                }
                elsif (/^\[([^\]]*)\]\s*$/) {
                        if (defined $section && 
                            $section eq $targetsection) {
                                $addfields->();
                        }

                        $section=expandenv($1);

                        push @out, $_;
                }
                elsif (/^(\w+)\s*=\s(.*)/) {
                        my $parameter=$1;
                        my $value=$2;

                        # continued value
                        while (@lines && $lines[0]=~/^\s(.+)/) {
                                shift(@lines);
                                $value.="\n$1";
                                chomp $value;
                        }

                        if ($section eq $targetsection) {
                                if (exists $changefields{$parameter}) {
                                        if (length $changefields{$parameter}) {
                                                $value=$changefields{$parameter};
                                        }
                                        delete $changefields{$parameter};
                                }
                        }

                        push @out, $formatfield->($parameter, $value);
                }
        }

        if (defined $section && 
            $section eq $targetsection) {
                $addfields->();
        }
        elsif (%changefields) {
                push @out, "\n[$targetsection]\n";
                foreach my $field (sort keys %changefields) {
                        if (length $changefields{$field}) {
                                push @out, $formatfield->($field, $changefields{$field});
                        }
                }
        }

        open(my $out, ">", $f) || die "mr: write $f: $!\n";
        print $out @out;
        close $out;     
}

sub dispatch {
        my $action=shift;

        # actions that do not operate on all repos
        if ($action eq 'config') {
                config(@ARGV);
        }
        elsif ($action eq 'register') {
                register(@ARGV);
        }
        elsif ($action eq 'bootstrap') {
                bootstrap();
        }
        elsif ($action eq 'remember' ||
               $action eq 'offline' ||
               $action eq 'online') {
                my @repos=selectrepos;
                action($action, @{$repos[0]}) if @repos;
                exit 0;
        }

        if (!$jobs || $jobs > 1) {
                mrs($action, selectrepos());
        }
        else {
                foreach my $repo (selectrepos()) {
                        record($repo, action($action, @$repo));
                }
        }
}

sub help {
        my $help=q#
                case `uname -s` in
                        SunOS)
                        SHOWMANFILE="man -f"
                        ;;
                        Darwin)
                        SHOWMANFILE="man"
                        ;;
                        *)
                        SHOWMANFILE="man"
                        ;;
                esac
                if [ ! -e "$MR_PATH" ]; then
                        error "cannot find program path"
                fi
                tmp=$(mktemp -t mr.XXXXXXXXXX) || error "mktemp failed"
                trap "rm -f $tmp" exit
                pod2man -c mr "$MR_PATH" > "$tmp" || error "pod2man failed"
                $SHOWMANFILE "$tmp" || error "man failed"
        #;
        exec($help) || die "exec: $!";
}

sub config {
        if (@_ < 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=$1;
                }
        }
        my %changefields;
        foreach (@_) {
                if (/^([^=]+)=(.*)$/) {
                        $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 config: $section $_ not set\n";
                        }
                }
        }
        modifyconfig($ENV{MR_CONFIG}, $section, %changefields) if %changefields;
        exit 0;
}

sub register {
        if ($config_overridden) {
                # Find the directory that the specified config file is
                # located in.
                ($directory)=abs_path($ENV{MR_CONFIG})=~/^(.*\/)[^\/]+$/;
        }
        else {
                # Find the closest known mrconfig file to the current
                # directory.
                $directory.="/" unless $directory=~/\/$/;
                my $foundconfig=0;
                foreach my $topdir (reverse sort keys %config) {
                        next unless length $topdir;
                        if ($directory=~/^\Q$topdir\E/) {
                                $ENV{MR_CONFIG}=$configfiles{$topdir};
                                $directory=$topdir;
                                $foundconfig=1;
                                last;
                        }
                }
                if (! $foundconfig) {
                        $directory=""; # no config file, use builtin
                }
        }
        if (@ARGV) {
                my $subdir=shift @ARGV;
                if (! chdir($subdir)) {
                        print STDERR "mr register: failed to chdir to $subdir: $!\n";
                }
        }

        $ENV{MR_REPO}=getcwd();
        my $command=findcommand("register", $ENV{MR_REPO}, $directory, 'DEFAULT', 0);
        if (! defined $command) {
                die "mr register: unknown repository type\n";
        }

        $ENV{MR_REPO}=~s/.*\/(.*)/$1/;
        $command="set -e; ".$config{$directory}{DEFAULT}{lib}."\n".
                "my_action(){ $command\n }; my_action ".
                join(" ", map { s/\\/\\\\/g; s/"/\"/g; '"'.$_.'"' } @ARGV);
        print "mr register: running >>$command<<\n" if $verbose;
        exec($command) || die "exec: $!";
}

sub bootstrap {
        eval q{use File::Copy};
        die $@ if $@;

        my $src=shift @ARGV;
        my $dir=shift @ARGV || ".";
        
        if (! defined $src || ! length $src) {
                die "mr: bootstrap requires source\n";
        }

        # Retrieve config file.
        eval q{use File::Temp};
        die $@ if $@;
        my $tmpconfig=File::Temp->new();
        if ($src =~ m!^[\w\d]+://!) {
                # Download the config file to a temporary location.
                my @downloader;
                if ($src =~ m!^ssh://(.*)!) {
                        @downloader = ("scp", $1, $tmpconfig);
                }
                else {
                        @downloader = ("curl", "-A", "mr", "-L", "-s", $src, "-o", $tmpconfig);
                        push(@downloader, "-k") if $insecure;
                }
                my $status = system(@downloader);
                die "mr bootstrap: invalid SSL certificate for $src (consider -k)\n"
                        if $downloader[0] eq 'curl' && $status >> 8 == 60;
                die "mr bootstrap: download of $src failed\n" if $status != 0;
        }
        elsif ($src eq '-') {
                # Config file is read from stdin.
                copy(\*STDIN, $tmpconfig) || die "stdin: $!";
        }
        else {
                # Config file is local.
                die "mr bootstrap: cannot read file '$src'"
                        unless -r $src;
                copy($src, $tmpconfig) || die "copy: $!";
        }

        # Sanity check on destination directory.
        if (! -e $dir) {
                system("mkdir", "-p", $dir);
        }
        chdir($dir) || die "chdir $dir: $!";

        # Special case to handle checkout of the "." repo, which 
        # would normally be skipped.
        my $topdir=abs_path(".")."/";
        my @repo=($topdir, $topdir, ".");
        loadconfig($tmpconfig, $topdir, $src);
        record(\@repo, action("checkout", @repo, 1))
                if exists $config{$topdir}{"."}{"checkout"};

        if (-e ".mrconfig") {
                print STDERR "mr bootstrap: .mrconfig file already exists, not overwriting with $src\n";
        }
        else {
                move($tmpconfig, ".mrconfig") || die "rename: $!";
        }

        # Reload the config file (in case we got a different version)
        # and checkout everything else.
        startingconfig();
        loadconfig(".mrconfig");
        dispatch("checkout");
        @skipped=grep { abs_path($_) ne abs_path($topdir) } @skipped;
        showstats("bootstrap");
        exitstats();
}

# alias expansion and command stemming
sub expandaction {
        my $action=shift;
        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";
                }
        }
        return $action;
}

sub find_mrconfig {
        my $dir=getcwd();
        while (length $dir) {
                if (-e "$dir/.mrconfig") {
                        return "$dir/.mrconfig";
                }
                $dir=~s/\/[^\/]*$//;
        }
        return $HOME_MR_CONFIG;
}

sub getopts {
        my @saved=@ARGV;
        Getopt::Long::Configure("bundling", "no_permute");
        my $result=GetOptions(
                "d|directory=s" => sub { $directory=abs_path($_[1]) },
                "c|config=s" => sub { $ENV{MR_CONFIG}=$_[1]; $config_overridden=1 },
                "p|path" => sub { }, # now default, ignore
                "f|force" => \$force,
                "v|verbose" => \$verbose,
                "m|minimal" => \$minimal,
                "q|quiet" => \$quiet,
                "s|stats" => \$stats,
                "k|insecure" => \$insecure,
                "i|interactive" => \$interactive,
                "n|no-recurse:i" => \$max_depth,
                "j|jobs:i" => \$jobs,
                "t|trust-all" => \$trust_all,
        );
        if (! $result || @ARGV < 1) {
                die("Usage: mr [options] action [params ...]\n".
                    "(Use mr help for man page.)\n");
        }
        
        $ENV{MR_SWITCHES}="";
        foreach my $option (@saved) {
                last if $option eq $ARGV[0];
                $ENV{MR_SWITCHES}.="$option ";
        }
}

sub check {
        my @env = qw(GIT_DIR VCSH_COMMAND);
        foreach (@env) {
                die ("mr: environment variable '$_' is set. You are about to shoot your own foot.\n") if ($ENV{$_});
        }
}

sub init {
        $SIG{INT}=sub {
                print STDERR "mr: interrupted\n";
                exit 2;
        };
        
        # This can happen if it's run in a directory that was removed
        # or other strangeness.
        if (! defined $directory) {
                die("mr: failed to determine working directory\n");
        }
        # Make sure MR_CONFIG is an absolute path, but don't use abs_path since
        # the config file might be a symlink to elsewhere, and the directory it's
        # in is significant.
        if ($ENV{MR_CONFIG} !~ /^\//) {
                $ENV{MR_CONFIG}=getcwd()."/".$ENV{MR_CONFIG};
        }
        # Try to set MR_PATH to the path to the program.
        eval {
                use FindBin qw($Bin $Script);
                $ENV{MR_PATH}=$Bin."/".$Script;
        };
}
        
sub exitstats {
        if (@failed) {
                exit 1;
        }
        else {
                exit 0;
        }
}

sub main {
        getopts();
        check();
        init();
        help(@ARGV) if $ARGV[0] eq 'help';

        startingconfig();
        loadconfig($HOME_MR_CONFIG);
        loadconfig($ENV{MR_CONFIG});
        #use Data::Dumper; print Dumper(\%config);
        
        my $action=expandaction(shift @ARGV);
        dispatch($action);

        showstats($action);
        exitstats();
}

# Finally, some useful actions that mr knows about by default.
# These can be overridden in ~/.mrconfig.
__DATA__
[ALIAS]
co = checkout
ci = commit
ls = list

[DEFAULT]
order = 10
lib =
        error() {
                echo "mr: $@" >&2
                exit 1
        }
        warning() {
                echo "mr (warning): $@" >&2
        }
        info() {
                echo "mr: $@" >&2
        }
        hours_since() {
                if [ -z "$1" ] || [ -z "$2" ]; then
                        error "mr: usage: hours_since action num"
                fi
                for dir in .git .svn .bzr CVS .hg _darcs _FOSSIL_; do
                        if [ -e "$MR_REPO/$dir" ]; then
                                flagfile="$MR_REPO/$dir/.mr_last$1"
                                break
                        fi
                done
                if [ -z "$flagfile" ]; then
                        error "cannot determine flag filename"
                fi
                delta=`perl -wle 'print -f shift() ? int((-M _) * 24) : 9999' "$flagfile"`
                if [ "$delta" -lt "$2" ]; then
                        return 1
                else
                        touch "$flagfile"
                        return 0
                fi
        }
        is_bzr_checkout() {
                LANG=C bzr info | egrep -q '^Checkout'
        }
        lazy() {
                if [ -d "$MR_REPO" ]; then
                        return 1
                else
                        return 0
                fi
        }

svn_test = perl: -d "$ENV{MR_REPO}/.svn"
git_test = perl: -e "$ENV{MR_REPO}/.git"
bzr_test = perl: -d "$ENV{MR_REPO}/.bzr"
cvs_test = perl: -d "$ENV{MR_REPO}/CVS"
hg_test  = perl: -d "$ENV{MR_REPO}/.hg"
darcs_test = perl: -d "$ENV{MR_REPO}/_darcs"
fossil_test = perl: -f "$ENV{MR_REPO}/_FOSSIL_"
git_bare_test = perl: 
        -d "$ENV{MR_REPO}/refs/heads" && -d "$ENV{MR_REPO}/refs/tags" &&
        -d "$ENV{MR_REPO}/objects" && -f "$ENV{MR_REPO}/config" &&
        `GIT_CONFIG="$ENV{MR_REPO}"/config git config --get core.bare` =~ /true/
vcsh_test = perl:
        -d "$ENV{MR_REPO}/refs/heads" && -d "$ENV{MR_REPO}/refs/tags" &&
        -d "$ENV{MR_REPO}/objects" && -f "$ENV{MR_REPO}/config" &&
        `GIT_CONFIG="$ENV{MR_REPO}"/config git config --get vcsh.vcsh` =~ /true/
veracity_test  = perl: -d "$ENV{MR_REPO}/.sgdrawer"

svn_update = svn update "$@"
git_update = git pull "$@"
bzr_update = 
        if is_bzr_checkout; then
                bzr update "$@"
        else
                bzr merge --pull "$@"
        fi
cvs_update = cvs -q update "$@"
hg_update  = hg pull "$@"; hg update "$@"
darcs_update = darcs pull -a "$@"
fossil_update = fossil pull "$@"
vcsh_update = vcsh run "$MR_REPO" git pull "$@"
veracity_update = vv pull "$@" && vv update "$@"

git_fetch = git fetch --all --prune --tags
git_svn_fetch = git svn fetch
darcs_fetch = darcs fetch
hg_fetch = hg pull

svn_clean = 
        if [ "x$1" = x-f ] ; then
                shift
                svn-clean "$@"
        else
                svn-clean --print "$@"
        fi
git_clean = 
        if [ "x$1" = x-f ] ; then
                shift
                git clean -dx --force "$@"
        else
                git clean -dx --dry-run "$@"
        fi
git_svn_clean = 
        if [ "x$1" = x-f ] ; then
                shift
                git clean -dx --force "$@"
        else
                git clean -dx --dry-run "$@"
        fi
bzr_clean = 
        if [ "x$1" = x-f ] ; then
                shift
                bzr clean-tree --verbose --force --ignored --unknown --detritus "$@"
        else
                bzr clean-tree --verbose --dry-run --ignored --unknown --detritus "$@"
        fi
cvs_clean = 
        if [ "x$1" = x-f ] ; then
                shift
                cvs-clean "$@"
        else
                cvs-clean --dry-run "$@"
        fi
hg_clean = 
        if [ "x$1" = x-f ] ; then
                shift
                hg purge --print --all "$@"
                hg purge --all "$@"
        else
                hg purge --print --all "$@"
        fi
fossil_clean = 
        if [ "x$1" = x-f ] ; then
                shift
                fossil clean --dry-run --dotfiles --emptydirs "$@"
        else
                fossil clean --force --dotfiles --emptydirs "$@"
        fi
vcsh_clean = 
        if [ "x$1" = x-f ] ; then
                shift
                vcsh run "$MR_REPO" git clean -dx "$@"
        else
                vcsh run "$MR_REPO" git clean -dx --dry-run "$@"
        fi

svn_status = svn status "$@"
git_status = git status -s "$@" || true; git --no-pager log --branches --not --remotes --simplify-by-decoration --decorate --oneline || true
bzr_status = bzr status --short "$@"; bzr missing
cvs_status = cvs -q status | grep -E '^(File:.*Status:|\?)' | grep -v 'Status: Up-to-date'
hg_status  = hg status "$@"; hg summary --quiet | grep -v 'parent: 0:'
darcs_status = darcs whatsnew -ls "$@" || true
fossil_status = fossil changes "$@"
vcsh_status = vcsh run "$MR_REPO" git -c status.relativePaths=false status -s "$@" || true
veracity_status = vv status "$@"

svn_commit = svn commit "$@"
git_commit = git commit -a "$@" && git push --all
bzr_commit = 
        if is_bzr_checkout; then
                bzr commit "$@"
        else
                bzr commit "$@" && bzr push
        fi
cvs_commit = cvs commit "$@"
hg_commit  = hg commit "$@" && hg push
darcs_commit = darcs record -a "$@" && darcs push -a
fossil_commit = fossil commit "$@"
vcsh_commit = vcsh run "$MR_REPO" git commit -a "$@" && vcsh run "$MR_REPO" git push --all
veracity_commit = vv commit "$@" && vv push

git_record = git commit -a "$@"
bzr_record =
        if is_bzr_checkout; then
                bzr commit --local "$@"
        else
                bzr commit "$@"
        fi
hg_record  = hg commit "$@"
darcs_record = darcs record -a "$@"
fossil_record = fossil commit "$@"
vcsh_record = vcsh run "$MR_REPO" git commit -a "$@"
veracity_record = vv commit "$@"

svn_push = :
git_push = git push "$@"
bzr_push = bzr push "$@"
cvs_push = :
hg_push = hg push "$@"
darcs_push = darcs push -a "$@"
fossil_push = fossil push "$@"
vcsh_push = vcsh run "$MR_REPO" git push "$@"
veracity_push = vv push "$@"

svn_diff = svn diff "$@"
git_diff = git diff "$@"
bzr_diff = bzr diff "$@"
cvs_diff = cvs -q diff "$@"
hg_diff  = hg diff "$@"
darcs_diff = darcs diff -u "$@"
fossil_diff = fossil diff "$@"
vcsh_diff = vcsh run "$MR_REPO" git diff "$@"
veracity_diff = vv diff "$@"

svn_log = svn log "$@"
git_log = git log "$@"
bzr_log = bzr log "$@"
cvs_log = cvs log "$@"
hg_log  = hg log "$@"
darcs_log = darcs changes "$@"
git_bare_log = git log "$@"
fossil_log = fossil timeline "$@"
vcsh_log = vcsh run "$MR_REPO" git log "$@"
veracity_log = vv log "$@"

hg_grep = hg grep "$@"
cvs_grep = ack-grep "$@"
svn_grep = ack-grep "$@"
git_svn_grep = git grep "$@"
git_grep = git grep "$@"
bzr_grep = ack-grep "$@"
darcs_grep = ack-grep "$@"

run = "$@"

svn_register =
        url=`LC_ALL=C svn info . | grep -i '^URL:' | cut -d ' ' -f 2`
        if [ -z "$url" ]; then
                error "cannot determine svn url"
        fi
        echo "Registering svn url: $url in $MR_CONFIG"
        mr -c "$MR_CONFIG" config "`pwd`" checkout="svn co '$url' '$MR_REPO'"
git_register = 
        url="`LC_ALL=C git config --get remote.origin.url`" || true
        if [ -z "$url" ]; then
                error "cannot determine git url"
        fi
        echo "Registering git url: $url in $MR_CONFIG"
        mr -c "$MR_CONFIG" config "`pwd`" checkout="git clone '$url' '$MR_REPO'"
bzr_register =
        url="`LC_ALL=C bzr info . | egrep -i 'checkout of branch|parent branch' | awk '{print $NF}' | head -n 1`"
        if [ -z "$url" ]; then
                error "cannot determine bzr url"
        fi
        echo "Registering bzr url: $url in $MR_CONFIG"
        mr -c "$MR_CONFIG" config "`pwd`" checkout="bzr branch '$url' '$MR_REPO'"
cvs_register =
        repo=`cat CVS/Repository`
        root=`cat CVS/Root`
        if [ -z "$root" ]; then
                error "cannot determine cvs root"
                fi
        echo "Registering cvs repository $repo at root $root"
        mr -c "$MR_CONFIG" config "`pwd`" checkout="cvs -d '$root' co -d '$MR_REPO' '$repo'"
hg_register = 
        url=`hg showconfig paths.default`
        echo "Registering mercurial repo url: $url in $MR_CONFIG"
        mr -c "$MR_CONFIG" config "`pwd`" checkout="hg clone '$url' '$MR_REPO'"
darcs_register = 
        url=`cat _darcs/prefs/defaultrepo`
        echo "Registering darcs repository $url in $MR_CONFIG"
        mr -c "$MR_CONFIG" config "`pwd`" checkout="darcs get '$url' '$MR_REPO'"
git_bare_register = 
        url="`LC_ALL=C GIT_CONFIG=config git config --get remote.origin.url`" || true
        if [ -z "$url" ]; then
                error "cannot determine git url"
        fi
        echo "Registering git url: $url in $MR_CONFIG"
        mr -c "$MR_CONFIG" config "`pwd`" checkout="git clone --bare '$url' '$MR_REPO'"
vcsh_register =
        url="`LC_ALL=C vcsh run "$MR_REPO" git config --get remote.origin.url`" || true
        if [ -z "$url" ]; then
                error "cannot determine git url"
        fi
        echo "Registering git url: $url in $MR_CONFIG"
        mr -c "$MR_CONFIG" config "`pwd`" checkout="vcsh clone '$url' '$MR_REPO'"
fossil_register =
        url=`fossil remote-url`
        repo=`fossil info | grep repository | sed -e 's/repository:*.//g' -e 's/ //g'`
        echo "Registering fossil repository $url in $MR_CONFIG"
        mr -c "$MR_CONFIG" config "`pwd`" checkout="mkdir -p '$MR_REPO' && cd '$MR_REPO' && fossil open '$repo'"
veracity_register =
        url=`vv config | grep sync_targets | sed -e 's/sync_targets:*.//g' -e 's/ //g'`
        repo=`vv repo info | grep repository | sed -e 's/Current repository:*.//g' -e 's/ //g'`
        echo "Registering veracity repository $url in $MR_CONFIG"
        mr -c "$MR_CONFIG" config "`pwd`" checkout="mkdir -p '$MR_REPO' && cd '$MR_REPO' && vv checkout '$repo'"

svn_trusted_checkout = svn co $url $repo
svn_alt_trusted_checkout = svn checkout $url $repo
git_trusted_checkout = git clone $url $repo
bzr_trusted_checkout = bzr checkout|clone|branch|get $url $repo
# cvs: too hard
hg_trusted_checkout = hg clone $url $repo
darcs_trusted_checkout = darcs get $url $repo
git_bare_trusted_checkout = git clone --bare $url $repo
vcsh_old_trusted_checkout = vcsh run "$MR_REPO" git clone $url $repo
vcsh_trusted_checkout = vcsh clone $url $repo
# fossil: messy to do
veracity_trusted_checkout = vv clone $url $repo


list = true
config = 
bootstrap = 

online =
        if [ -s ~/.mrlog ]; then
                info "running offline commands"
                mv -f ~/.mrlog ~/.mrlog.old
                if ! sh -e ~/.mrlog.old; then
                        error "offline command failed; left in ~/.mrlog.old"
                fi
                rm -f ~/.mrlog.old
        else
                info "no offline commands to run"
        fi
offline =
        umask 077
        touch ~/.mrlog
        info "offline mode enabled"
remember =
        info "remembering command: 'mr $@'"
        command="mr -d '$(pwd)' $MR_SWITCHES"
        for w in "$@"; do
                command="$command '$w'"
        done
        if [ ! -e ~/.mrlog ] || ! grep -q -F "$command" ~/.mrlog; then
                echo "$command" >> ~/.mrlog
        fi

ed = echo "A horse is a horse, of course, of course.."
T = echo "I pity the fool."
right = echo "Not found."

# vim:sw=8:sts=0:ts=8:noet
# Local variables:
# indent-tabs-mode: t
# cperl-indent-level: 8
# End: