bugfixes developed while writing blog post

[code/myrepos.git] / mr

diff --git a/mr b/mr
index aa15728925c0b3ee00cd09acce516e1cda41e2e1..96f3a16cbd4f2332194823ae9126dcb1ba16faf6 100755 (executable)
--- a/mr
+++ b/mr
@@ -12,7 +12,15 @@ B<mr> [options] update
 
 B<mr> [options] status
 
 
 B<mr> [options] status
 

-B<mr> [options] commit -m "message"
+B<mr> [options] commit [-m "message"]
+
+B<mr> [options] diff
+
+B<mr> [options] log
+
+B<mr> [options] register repository
+
+B<mr> [options] config section [parameter=[value] ...]

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


@@ -20,10 +28,85 @@ B<mr> [options] action [params ...]
 
 B<mr> is a Multiple Repository management tool. It allows you to register a
 set of repositories in a .mrconfig file, and then checkout, update, or
 
 B<mr> is a Multiple Repository management tool. It allows you to register a
 set of repositories in a .mrconfig file, and then checkout, update, or

-perform other actions on all of the repositories at once.
+perform other actions on the repositories as if they were one big
+respository.

 
 Any mix of revision control systems can be used with B<mr>, and you can
 
 Any mix of revision control systems can be used with B<mr>, and you can

-define arbitrary actions like "update", "checkout", or "commit".
+define arbitrary actions for commands like "update", "checkout", or "commit".
+
+B<mr> cds into and operates on all registered repsitories 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,
+
+The predefined commands should be fairly familiar to users of any revision
+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.
+
+=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.)
+
+The optional -m parameter allows specifying a commit message.
+
+=item diff
+
+Show a diff of uncommitted changes.
+
+=item log
+
+Show the commit log.
+
+=item list (or ls)
+
+List the repositories that mr will act on.
+
+=item register
+
+The next parameter is the directory of an existing repository. The
+repository will be registered in the mrconfig file.
+
+=item config
+
+Modifies the mrconfig file. The next parameter is the name of the section
+to add or modify, and it is followed by one or more instances of
+"parameter=value". Use "parameter=" to remove a parameter. 
+
+For example, to add (or edit) a repository in src/foo:
+
+  mr config src/foo checkout="svn co svn://example.com/foo/trunk foo"
+
+=item help
+
+Displays this help.
+
+=back
+
+Actions can be abbreviated to any unambiguous subsctring, so
+"mr st" is equivilant to "mr status", and "mr up" is equivilant to "mr
+update"
+
+Additional parameters can be passed to most commands, and are passed on
+unchanged to the underlying revision control system. This is mostly useful
+if the repositories mr will act on all use the same revision control
+system.

 
 =head1 OPTIONS
 
 
 =head1 OPTIONS
 


@@ -32,12 +115,11 @@ define arbitrary actions like "update", "checkout", or "commit".
 =item -d directory
 
 Specifies the topmost directory that B<mr> should work in. The default is
 =item -d directory
 
 Specifies the topmost directory that B<mr> should work in. The default is

-the current working directory. B<mr> will operate on all registered
-repositories at or under the directory.
+the current working directory.

 
 =item -c mrconfig
 
 
 =item -c mrconfig
 

-Use the specified mrconfig file, instead of looking for on in your home
+Use the specified mrconfig file, instead of looking for one in your home

 directory.
 
 =item -v
 directory.
 
 =item -v


@@ -48,40 +130,76 @@ Be verbose.
 
 =head1 FILES
 
 
 =head1 FILES
 

-B<mr> is configured by .mrconfig files. It searches for .mrconfig files in
-your home directory, and in the root directory of each repository specified
-in a .mrconfig file. So you could have a ~/.mrconfig that registers a
-repository ~/src, that itself contains a ~/src/.mrconfig file, that in turn
-registers several additional repositories.
+B<mr> is configured by .mrconfig files. It starts by reading the .mrconfig
+file in your home directory, and this can in turn chain load .mrconfig files
+from repositories.
+
+Here is an example .mrconfig file:
+
+  [src]
+  checkout = svn co 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

 
 The .mrconfig file uses a variant of the INI file format. Lines starting with
 "#" are comments. Lines ending with "\" are continued on to the next line.
 
 The .mrconfig file uses a variant of the INI file format. Lines starting with
 "#" are comments. Lines ending with "\" are continued on to the next line.

-Sections specify where each repository is located, relative to the
-directory that contains the .mrconfig file.
+
+The "DEFAULT" section allows setting default values for the sections that
+come after it.
+
+The "ALIAS" section allows adding aliases for actions. Each parameter
+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.

 
 Within a section, each parameter defines a shell command to run to handle a
 
 Within a section, each parameter defines a shell command to run to handle a

-given action. Note that these shell commands are run in a "set -e" shell
-environment, and B<mr> cds into the repository directory before running
-them, except for the "checkout" command, which is run in the parent of the
-repository directory, since the repository isn't checked out yet.
+given action. mr contains default handlers for the "update", "status", and
+"commit" actions, so normally you only need to specify what to do for
+"checkout".

 
 

-There are two special parameters. If the "skip" parameter is set and
-its command returns nonzero, then B<mr> will skip acting on that repository.
+Note that these shell commands are run in a "set -e" shell
+environment, where any additional parameters you pass are available in
+"$@". The "checkout" command is run in the parent of the repository
+directory, since the repository isn't checked out yet. All other commands
+are run inside the repository, though not necessarily at the top of it.
+The "MR_REPO" environment variable is set to the path to the top of the
+repository.

 
 

-The "default" section allows setting up default handlers for each action,
-and is overridden by the contents of other sections. mr contains default
-handlers for the "update", "status", and "commit" actions, so normally
-you only need to specify what to do for "checkout".
+A few parameters have special meanings:

 
 

-For example:
+=over 4

 
 

-  [src]
-  checkout = svn co svn://svn.example.com/src/trunk src
+=item skip

 
 

-  [src/linux-2.6]
-  # only check this out on kodama
-  skip = test $(hostname) != kodama
-  checkout = git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
+If the "skip" parameter is set and its command returns nonzero, then B<mr>
+will skip acting on that repository.
+
+=item chain
+
+If the "chain" parameter is set and its command returns nonzero, then B<mr>
+will try to load a .mrconfig file from the root of the repository. (You
+should avoid chaining from repositories with untrusted committers.)
+
+=item deleted
+
+If the "deleted" parameter is set and its command returns nonzero, 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 repsoitory's directory.
+This is useful when one mrconfig file is shared amoung multiple machines,
+to keep track of and remember to delete old repositories.
+
+=item lib
+
+The "lib" parameter can specify 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.
+
+=back

 
 =head1 AUTHOR
 
 
 =head1 AUTHOR
 


@@ -102,84 +220,208 @@ my $directory=getcwd();
 my $config="$ENV{HOME}/.mrconfig";
 my $verbose=0;
 my %config;
 my $config="$ENV{HOME}/.mrconfig";
 my $verbose=0;
 my %config;

+my %knownactions;
+my %alias;

 
 Getopt::Long::Configure("no_permute");
 my $result=GetOptions(
 
 Getopt::Long::Configure("no_permute");
 my $result=GetOptions(

-       "d=s" => sub { $directory=abs_path($_[1]) },
-       "c=s" => \$config,
-       "v" => \$verbose,
+       "d|directory=s" => sub { $directory=abs_path($_[1]) },
+       "c|config=s" => \$config,
+       "verbose" => \$verbose,

 );
 if (! $result || @ARGV < 1) {
 );
 if (! $result || @ARGV < 1) {

-       die("Usage: mr [-d directory] action [params ...]\n");
+       die("Usage: mr [-d directory] action [params ...]\n".
+           "(Use mr help for man page.)\n");
+

 }
 }

-my $action=shift @ARGV;

 
 loadconfig(\*DATA);
 loadconfig($config);
 #use Data::Dumper;
 #print Dumper(\%config);
 
 
 loadconfig(\*DATA);
 loadconfig($config);
 #use Data::Dumper;
 #print Dumper(\%config);
 

-my (@failures, @successes, @skipped);
-my $first=1;
+eval {
+       use FindBin qw($Bin $Script);
+       $ENV{MR_PATH}=$Bin."/".$Script;
+};
+
+# 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";
+       }
+}
+
+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 $config's dir
+               my ($dir)=$config=~/^(.*\/)[^\/]+$/;
+               if ($section=~/^\Q$dir\E(.*)/) {
+                       $section=$1;
+               }
+       }
+       my %fields;
+       foreach (@ARGV) {
+               if (/^([^=]+)=(.*)$/) {
+                       $fields{$1}=$2;
+               }
+               else {
+                       die "mr config: expected parameter=value, not \"$_\"\n";
+               }
+       }
+       modifyconfig($config, $section, %fields);
+       exit 0;
+}
+elsif ($action eq 'register') {
+       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;

 foreach my $topdir (sort keys %config) {
        foreach my $subdir (sort keys %{$config{$topdir}}) {
 foreach my $topdir (sort keys %config) {
        foreach my $subdir (sort keys %{$config{$topdir}}) {

-               next if $subdir eq 'default';
-               
-               my $dir=$topdir.$subdir;
-
-               if (defined $directory &&
-                   $dir !~ /^\Q$directory\E\//) {
-                       print "mr $action: $dir skipped per -d parameter\n" if $verbose;
-                       push @skipped, $dir;
-                       next;
+               next if $subdir eq 'DEFAULT';
+               my $dir=($subdir =~/^\//) ? $subdir : $topdir.$subdir;
+               my $d=$directory;
+               $dir.="/" unless $dir=~/\/$/;
+               $d.="/" unless $d=~/\/$/;
+               next if $dir ne $directory && $dir !~ /^\Q$directory\E/;
+               push @repos, [$dir, $topdir, $subdir];
+       }
+}
+if (! @repos) {
+       # fallback to find a leaf repo
+       LEAF: foreach my $topdir (reverse sort keys %config) {
+               foreach my $subdir (reverse sort keys %{$config{$topdir}}) {
+                       next if $subdir eq 'DEFAULT';
+                       my $dir=($subdir =~/^\//) ? $subdir : $topdir.$subdir;
+                       my $d=$directory;
+                       $dir.="/" unless $dir=~/\/$/;
+                       $d.="/" unless $d=~/\/$/;
+                       if ($d=~/^\Q$dir\E/) {
+                               push @repos, [$dir, $topdir, $subdir];
+                               last LEAF;
+                       }

                }
                }

+       }
+       $nochdir=1;
+}

 
 

-               print "\n" unless $first;
-               $first=0;
+my (@failed, @successful, @skipped);
+foreach my $repo (@repos) {
+       action($action, @$repo);
+}
+
+sub action {
+       my ($action, $dir, $topdir, $subdir) = @_;
+       
+       my $lib= exists $config{$topdir}{$subdir}{lib} ?
+                       $config{$topdir}{$subdir}{lib}."\n" : "";

 
 

-               if (exists $config{$topdir}{$subdir}{skip}) {
-                       my $ret=system($config{$topdir}{$subdir}{skip});
+       if (exists $config{$topdir}{$subdir}{deleted}) {
+               if (! -d $dir) {
+                       return;
+               }
+               else {
+                       my $test="set -e;".$lib.$config{$topdir}{$subdir}{deleted};
+                       print "mr $action: running deleted test >>$test<<\n" if $verbose;
+                       my $ret=system($test);

                        if ($ret >> 8 == 0) {
                        if ($ret >> 8 == 0) {

-                               print "mr $action: $dir skipped per config file\n" if $verbose;
-                               push @skipped, $dir;
-                               next;
+                               print STDERR "mr error: $dir should be deleted yet still exists\n\n";
+                               push @failed, $dir;
+                               return;

                        }
                }
                        }
                }

+       }

 
 

-               if ($action eq 'checkout') {
-                       if (-e $dir) {
-                               print "mr $action: $dir already exists, skipping checkout\n";
-                               push @skipped, $dir;
-                               next;
-                       }
-                       $dir=~s/^(.*)\/[^\/]+\/?$/$1/;
-               }
-               if (! chdir($dir)) {
-                       print STDERR "mr $action: failed to chdir to $dir: $!\n";
+       if ($action eq 'checkout') {
+               if (-d $dir) {
+                       print "mr $action: $dir already exists, skipping checkout\n" if $verbose;

                        push @skipped, $dir;
                        push @skipped, $dir;

+                       return;
+               }
+               $dir=~s/^(.*)\/[^\/]+\/?$/$1/;
+       }
+       elsif ($action eq 'update') {
+               if (! -d $dir) {
+                       return action("checkout", $dir, $topdir, $subdir);

                }
                }

-               elsif (! exists $config{$topdir}{$subdir}{$action}) {
-                       print STDERR "mr $action: no defined $action command for $topdir$subdir, skipping\n";
+       }
+       
+       $ENV{MR_REPO}=$dir;
+
+       if (exists $config{$topdir}{$subdir}{skip}) {
+               my $test="set -e;".$lib.$config{$topdir}{$subdir}{skip};
+               print "mr $action: running skip test >>$test<<\n" if $verbose;
+               my $ret=system($test);
+               if ($ret >> 8 == 0) {
+                       print "mr $action: $dir skipped per config file\n" if $verbose;

                        push @skipped, $dir;
                        push @skipped, $dir;

+                       return;
+               }
+       }
+       
+       if (! $nochdir && ! chdir($dir)) {
+               print STDERR "mr $action: failed to chdir to $dir: $!\n";
+               push @failed, $dir;
+       }
+       elsif (! exists $config{$topdir}{$subdir}{$action}) {
+               print STDERR "mr $action: no defined $action command for $topdir$subdir, skipping\n";
+               push @skipped, $dir;
+       }
+       else {
+               if (! $nochdir) {
+                       print "mr $action: $topdir$subdir\n";

                }
                else {
                }
                else {

-                       print "mr $action: in $dir\n";
-                       my $command="set -e; my_action(){ $config{$topdir}{$subdir}{$action} ; }; my_action @ARGV";
-                       my $ret=system($command);
-                       if ($ret != 0) {
-                               print STDERR "mr $action: failed to run: $command\n" if $verbose;
-                               push @failures, $topdir.$subdir;
-                               if ($ret >> 8 != 0) {
-                                       print STDERR "mr $action: command failed\n";
-                               }
-                               elsif ($ret != 0) {
-                                       print STDERR "mr $action: command died ($ret)\n";
-                               }
+                       print "mr $action: $topdir$subdir (in subdir $directory)\n";
+               }
+               my $command="set -e; ".$lib.
+                       "my_action(){ $config{$topdir}{$subdir}{$action}\n }; my_action ".
+                       join(" ", map { s/\//\/\//g; s/"/\"/g; '"'.$_.'"' } @ARGV);
+               print STDERR "mr $action: running >>$command<<\n" if $verbose;
+               my $ret=system($command);
+               if ($ret != 0) {
+                       print STDERR "mr $action: failed ($ret)\n" if $verbose;
+                       push @failed, $dir;
+                       if ($ret >> 8 != 0) {
+                               print STDERR "mr $action: command failed\n";

                        }
                        }

-                       else {
-                               push @successes, $dir;
+                       elsif ($ret != 0) {
+                               print STDERR "mr $action: command died ($ret)\n";

                        }
                }
                        }
                }

+               else {
+                       push @successful, $dir;
+               }
+
+               print "\n";

        }
 }
 
        }
 }
 


@@ -192,12 +434,21 @@ sub showstat {
        }
        return;
 }
        }
        return;
 }

-print "\nmr $action: finished (".join("; ",
-       showstat($#successes+1, "success", "sucesses"),
-       showstat($#failures+1, "failure", "failures"),
+if (! @successful && ! @failed && ! @skipped) {
+       die "mr $action: no repositories found to work on\n";
+}
+print "mr $action: finished (".join("; ",
+       showstat($#successful+1, "successful", "successful"),
+       showstat($#failed+1, "failed", "failed"),

        showstat($#skipped+1, "skipped", "skipped"),
 ).")\n";
        showstat($#skipped+1, "skipped", "skipped"),
 ).")\n";

-exit @failures ? 1 : 0;
+if (@failed) {
+       exit 1;
+}
+elsif (! @successful && @skipped) {
+       exit 1;
+}
+exit 0;

 
 my %loaded;
 sub loadconfig {
 
 my %loaded;
 sub loadconfig {


@@ -212,23 +463,30 @@ sub loadconfig {
                $dir="";
        }
        else {
                $dir="";
        }
        else {

-               $f=abs_path($f);
+               if (! -e $f) {
+                       return;
+               }

 
 

-               if ($loaded{$f}) {
+               my $absf=abs_path($f);
+               if ($loaded{$absf}) {

                        return;
                }
                        return;
                }

-               $loaded{$f}=1;
+               $loaded{$absf}=1;

 
                print "mr: loading config $f\n" if $verbose;
                open($in, "<", $f) || die "mr: open $f: $!\n";
                ($dir)=$f=~/^(.*\/)[^\/]+$/;
 
                print "mr: loading config $f\n" if $verbose;
                open($in, "<", $f) || die "mr: open $f: $!\n";
                ($dir)=$f=~/^(.*\/)[^\/]+$/;

+               if (! defined $dir) {
+                       $dir=".";
+               }
+               $dir=abs_path($dir)."/";

 
                # copy in defaults from first parent
                my $parent=$dir;
                while ($parent=~s/^(.*)\/[^\/]+\/?$/$1/) {
                        if (exists $config{$parent} &&
 
                # copy in defaults from first parent
                my $parent=$dir;
                while ($parent=~s/^(.*)\/[^\/]+\/?$/$1/) {
                        if (exists $config{$parent} &&

-                           exists $config{$parent}{default}) {
-                               $config{$dir}{default}={ %{$config{$parent}{default}} };
+                           exists $config{$parent}{DEFAULT}) {
+                               $config{$dir}{DEFAULT}={ %{$config{$parent}{DEFAULT}} };

                                last;
                        }
                }
                                last;
                        }
                }


@@ -240,33 +498,45 @@ sub loadconfig {
                next if /^\s*\#/ || /^\s*$/;
                if (/^\s*\[([^\]]*)\]\s*$/) {
                        $section=$1;
                next if /^\s*\#/ || /^\s*$/;
                if (/^\s*\[([^\]]*)\]\s*$/) {
                        $section=$1;

-                       if (length $dir && $section ne "default" &&
-                           -e $dir.$section."/.mrconfig") {
-                               push @toload, $dir.$section."/.mrconfig";
-                       }

                }
                elsif (/^\s*(\w+)\s*=\s*(.*)/) {
                        my $parameter=$1;
                        my $value=$2;
 
                        # continuation line
                }
                elsif (/^\s*(\w+)\s*=\s*(.*)/) {
                        my $parameter=$1;
                        my $value=$2;
 
                        # continuation line

-                       while ($value=~/(.*)\\$/) {
-                               $value=$1.<$in>;
+                       while ($value=~/(.*)\\$/s) {
+                               $value=$1."\n".<$in>;

                                chomp $value;
                        }
 
                        if (! defined $section) {
                                die "$f line $.: parameter ($parameter) not in section\n";
                        }
                                chomp $value;
                        }
 
                        if (! defined $section) {
                                die "$f line $.: parameter ($parameter) not in section\n";
                        }

-                       if (! exists $config{$dir}{$section} &&
-                             exists $config{$dir}{default}) {
+                       if ($section ne 'ALIAS' &&
+                           ! exists $config{$dir}{$section} &&
+                           exists $config{$dir}{DEFAULT}) {

                                # copy in defaults
                                # copy in defaults

-                               $config{$dir}{$section}={ %{$config{$dir}{default}} };
+                               $config{$dir}{$section}={ %{$config{$dir}{DEFAULT}} };
+                       }
+                       if ($section eq 'ALIAS') {
+                               $alias{$parameter}=$value;
+                       }
+                       elsif ($parameter eq 'lib') {
+                               $config{$dir}{$section}{lib}.=$value."\n";
+                       }
+                       else {
+                               $config{$dir}{$section}{$parameter}=$value;
+                               $knownactions{$parameter}=1;
+                               if ($parameter eq 'chain' &&
+                                   length $dir && $section ne "DEFAULT" &&
+                                   -e $dir.$section."/.mrconfig" &&
+                                   system($value) >> 8 == 0) {
+                                       push @toload, $dir.$section."/.mrconfig";
+                               }

                        }
                        }

-                       $config{$dir}{$section}{$parameter}=$value;

                }
                else {
                }
                else {

-                               die "$f line $.: parse error\n";
+                       die "$f line $.: parse error\n";

                }
        }
        close $in;
                }
        }
        close $in;


@@ -276,34 +546,201 @@ sub loadconfig {
        }
 }
 
        }
 }
 

-__DATA__
-# Some useful actions that mr knows about by default.
+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 $addfields=sub {
+               my @blanks;
+               while ($out[$#out] =~ /^\s*$/) {
+                       unshift @blanks, pop @out;
+               }
+               foreach my $field (sort keys %changefields) {
+                       if (length $changefields{$field}) {
+                               push @out, "$field = $changefields{$field}\n";
+                       }
+               }
+               push @out, @blanks;
+       };
+
+       my $section;
+       while (@lines) {
+               $_=shift(@lines);
+
+               if (/^\s*\#/ || /^\s*$/) {
+                       push @out, $_;
+               }
+               elsif (/^\s*\[([^\]]*)\]\s*$/) {
+                       if (defined $section && 
+                           $section eq $targetsection) {
+                               $addfields->();
+                       }
+
+                       $section=$1;
+
+                       push @out, $_;
+               }
+               elsif (/^\s*(\w+)\s*=\s(.*)/) {
+                       my $parameter=$1;
+                       my $value=$2;
+
+                       # continuation line
+                       while ($value=~/(.*\\)$/s) {
+                               $value=$1."\n".shift(@lines);
+                               chomp $value;
+                       }
+
+                       if ($section eq $targetsection) {
+                               if (exists $changefields{$parameter}) {
+                                       if (length $changefields{$parameter}) {
+                                               $value=$changefields{$parameter};
+                                       }
+                                       delete $changefields{$parameter};
+                               }
+                       }
+
+                       push @out, "$parameter = $value\n";
+               }
+       }
+
+       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, "$field = $changefields{$field}\n";
+                       }
+               }
+       }
+
+       open(my $out, ">", $f) || die "mr: write $f: $!\n";
+       print $out @out;
+       close $out;     
+}
+
+# Finally, some useful actions that mr knows about by default.

 # These can be overridden in ~/.mrconfig.
 # These can be overridden in ~/.mrconfig.

-[default]
-update = \
-       if [ -d .svn ]; then \
-               svn update; \
-       elif [ -d .git ]; then \
-               git pull origin master; \
-       else \
-               echo "mr update: unknown RCS"; \
-               exit 1; \
+__DATA__
+[ALIAS]
+       co = checkout
+       ci = commit
+       ls = list
+
+[DEFAULT]
+lib =                                                  \
+       error() {                                       \
+               echo "mr: $@" >&2                       \
+               exit 1                                  \
+       }
+
+update =                                               \
+       if [ -d "$MR_REPO"/.svn ]; then                 \
+               svn update "$@"                         \
+       elif [ -d "$MR_REPO"/.git ]; then               \
+               git pull origin master "$@"             \
+       elif [ -d "$MR_REPO"/.bzr ]; then               \
+               bzr merge "$@"                          \
+       elif [ -d "$MR_REPO"/CVS ]; then                \
+               cvs update "$@"                         \
+       else                                            \
+               error "unknown repo type"               \
+       fi
+status =                                               \
+       if [ -d "$MR_REPO"/.svn ]; then                 \
+               svn status "$@"                         \
+       elif [ -d "$MR_REPO"/.git ]; then               \
+               git status "$@" || true                 \
+       elif [ -d "$MR_REPO"/.bzr ]; then               \
+               bzr status "$@"                         \
+       elif [ -d "$MR_REPO"/CVS ]; then                \
+               cvs status "$@"                         \
+       else                                            \
+               error "unknown repo type"               \
+       fi
+commit =                                               \
+       if [ -d "$MR_REPO"/.svn ]; then                 \
+               svn commit "$@"                         \
+       elif [ -d "$MR_REPO"/.git ]; then               \
+               git commit -a "$@" && git push --all    \
+       elif [ -d "$MR_REPO"/.bzr ]; then               \
+               bzr commit "$@" && bzr push             \
+       elif [ -d "$MR_REPO"/CVS ]; then                \
+               cvs commit "$@"                         \
+       else                                            \
+               error "unknown repo type"               \
+       fi
+diff =                                                 \
+       if [ -d "$MR_REPO"/.svn ]; then                 \
+               svn diff "$@"                           \
+       elif [ -d "$MR_REPO"/.git ]; then               \
+               git diff "$@"                           \
+       elif [ -d "$MR_REPO"/.bzr ]; then               \
+               bzr diff "$@"                           \
+       elif [ -d "$MR_REPO"/CVS ]; then                \
+               cvs diff "$@"                           \
+       else                                            \
+               error "unknown repo type"               \

        fi
        fi

-status = \
-       if [ -d .svn ]; then \
-               svn status; \
-       elif [ -d .git ]; then \
-               git status || true; \
-       else \
-               echo "mr status: unknown RCS"; \
-               exit 1; \
+log =                                                  \
+       if [ -d "$MR_REPO"/.svn ]; then                 \
+               svn log"$@"                             \
+       elif [ -d "$MR_REPO"/.git ]; then               \
+               git log "$@"                            \
+       elif [ -d "$MR_REPO"/.bzr ]; then               \
+               bzr log "$@"                            \
+       elif [ -d "$MR_REPO"/CVS ]; then                \
+               cvs log "$@"                            \
+       else                                            \
+               error "unknown repo type"               \

        fi
        fi

-commit = \
-       if [ -d .svn ]; then \
-               svn commit "$@"; \
-       elif [ -d .git ]; then \
-               git commit -a "$@"; \
-       else \
-               echo "mr commit: unknown RCS"; \
-               exit 1; \
+register =                                                             \
+       if [ -z "$1" ]; then                                            \
+               error "repository directory not specified"              \
+       fi                                                              \
+       cd "$1"                                                         \
+       basedir="$(basename $(pwd))"                                    \
+       if [ -d .svn ]; then                                            \
+               url=$(svn info . |                                      \
+                     grep -i ^URL: | cut -d ' ' -f 2)                  \
+               if [ -z "$url" ]; then                                  \
+                       error "cannot determine svn url"                \
+               fi                                                      \
+               echo "Registering svn url: $url"                        \
+               mr config "$(pwd)" checkout="svn co $url $basedir"      \
+       elif [ -d .git ]; then                                          \
+               url=$(git-config --get remote.origin.url)               \
+               if [ -z "$url" ]; then                                  \
+                       error "cannot determine git url"                \
+               fi                                                      \
+               echo "Registering git url: $url"                        \
+               mr config "$(pwd)" checkout="git clone $url $basedir"   \
+       else                                                            \
+               error "unable to register this repo type"               \

        fi
        fi

+list = true
+config = 
+help =                                                 \
+       if [ ! -e "$MR_PATH" ]; then                    \
+               error "cannot find program path"        \
+       fi                                              \
+       (pod2man -c mr "$MR_PATH" | man -l -) ||        \
+               error "pod2man or man failed"
+
+ed = echo "A horse is a horse, of course, of course.."
+T = echo "I pity the fool."