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-rw-r--r--perl/.gitignore5
-rw-r--r--perl/Git.pm878
-rw-r--r--perl/Makefile42
-rw-r--r--perl/Makefile.PL33
-rw-r--r--perl/private-Error.pm827
5 files changed, 1785 insertions, 0 deletions
diff --git a/perl/.gitignore b/perl/.gitignore
new file mode 100644
index 0000000000..98b24772c7
--- /dev/null
+++ b/perl/.gitignore
@@ -0,0 +1,5 @@
+perl.mak
+perl.mak.old
+blib
+blibdirs
+pm_to_blib
diff --git a/perl/Git.pm b/perl/Git.pm
new file mode 100644
index 0000000000..8fd3611753
--- /dev/null
+++ b/perl/Git.pm
@@ -0,0 +1,878 @@
+=head1 NAME
+
+Git - Perl interface to the Git version control system
+
+=cut
+
+
+package Git;
+
+use strict;
+
+
+BEGIN {
+
+our ($VERSION, @ISA, @EXPORT, @EXPORT_OK);
+
+# Totally unstable API.
+$VERSION = '0.01';
+
+
+=head1 SYNOPSIS
+
+ use Git;
+
+ my $version = Git::command_oneline('version');
+
+ git_cmd_try { Git::command_noisy('update-server-info') }
+ '%s failed w/ code %d';
+
+ my $repo = Git->repository (Directory => '/srv/git/cogito.git');
+
+
+ my @revs = $repo->command('rev-list', '--since=last monday', '--all');
+
+ my ($fh, $c) = $repo->command_output_pipe('rev-list', '--since=last monday', '--all');
+ my $lastrev = <$fh>; chomp $lastrev;
+ $repo->command_close_pipe($fh, $c);
+
+ my $lastrev = $repo->command_oneline( [ 'rev-list', '--all' ],
+ STDERR => 0 );
+
+=cut
+
+
+require Exporter;
+
+@ISA = qw(Exporter);
+
+@EXPORT = qw(git_cmd_try);
+
+# Methods which can be called as standalone functions as well:
+@EXPORT_OK = qw(command command_oneline command_noisy
+ command_output_pipe command_input_pipe command_close_pipe
+ version exec_path hash_object git_cmd_try);
+
+
+=head1 DESCRIPTION
+
+This module provides Perl scripts easy way to interface the Git version control
+system. The modules have an easy and well-tested way to call arbitrary Git
+commands; in the future, the interface will also provide specialized methods
+for doing easily operations which are not totally trivial to do over
+the generic command interface.
+
+While some commands can be executed outside of any context (e.g. 'version'
+or 'init'), most operations require a repository context, which in practice
+means getting an instance of the Git object using the repository() constructor.
+(In the future, we will also get a new_repository() constructor.) All commands
+called as methods of the object are then executed in the context of the
+repository.
+
+Part of the "repository state" is also information about path to the attached
+working copy (unless you work with a bare repository). You can also navigate
+inside of the working copy using the C<wc_chdir()> method. (Note that
+the repository object is self-contained and will not change working directory
+of your process.)
+
+TODO: In the future, we might also do
+
+ my $remoterepo = $repo->remote_repository (Name => 'cogito', Branch => 'master');
+ $remoterepo ||= Git->remote_repository ('http://git.or.cz/cogito.git/');
+ my @refs = $remoterepo->refs();
+
+Currently, the module merely wraps calls to external Git tools. In the future,
+it will provide a much faster way to interact with Git by linking directly
+to libgit. This should be completely opaque to the user, though (performance
+increate nonwithstanding).
+
+=cut
+
+
+use Carp qw(carp croak); # but croak is bad - throw instead
+use Error qw(:try);
+use Cwd qw(abs_path);
+
+}
+
+
+=head1 CONSTRUCTORS
+
+=over 4
+
+=item repository ( OPTIONS )
+
+=item repository ( DIRECTORY )
+
+=item repository ()
+
+Construct a new repository object.
+C<OPTIONS> are passed in a hash like fashion, using key and value pairs.
+Possible options are:
+
+B<Repository> - Path to the Git repository.
+
+B<WorkingCopy> - Path to the associated working copy; not strictly required
+as many commands will happily crunch on a bare repository.
+
+B<WorkingSubdir> - Subdirectory in the working copy to work inside.
+Just left undefined if you do not want to limit the scope of operations.
+
+B<Directory> - Path to the Git working directory in its usual setup.
+The C<.git> directory is searched in the directory and all the parent
+directories; if found, C<WorkingCopy> is set to the directory containing
+it and C<Repository> to the C<.git> directory itself. If no C<.git>
+directory was found, the C<Directory> is assumed to be a bare repository,
+C<Repository> is set to point at it and C<WorkingCopy> is left undefined.
+If the C<$GIT_DIR> environment variable is set, things behave as expected
+as well.
+
+You should not use both C<Directory> and either of C<Repository> and
+C<WorkingCopy> - the results of that are undefined.
+
+Alternatively, a directory path may be passed as a single scalar argument
+to the constructor; it is equivalent to setting only the C<Directory> option
+field.
+
+Calling the constructor with no options whatsoever is equivalent to
+calling it with C<< Directory => '.' >>. In general, if you are building
+a standard porcelain command, simply doing C<< Git->repository() >> should
+do the right thing and setup the object to reflect exactly where the user
+is right now.
+
+=cut
+
+sub repository {
+ my $class = shift;
+ my @args = @_;
+ my %opts = ();
+ my $self;
+
+ if (defined $args[0]) {
+ if ($#args % 2 != 1) {
+ # Not a hash.
+ $#args == 0 or throw Error::Simple("bad usage");
+ %opts = ( Directory => $args[0] );
+ } else {
+ %opts = @args;
+ }
+ }
+
+ if (not defined $opts{Repository} and not defined $opts{WorkingCopy}) {
+ $opts{Directory} ||= '.';
+ }
+
+ if ($opts{Directory}) {
+ -d $opts{Directory} or throw Error::Simple("Directory not found: $!");
+
+ my $search = Git->repository(WorkingCopy => $opts{Directory});
+ my $dir;
+ try {
+ $dir = $search->command_oneline(['rev-parse', '--git-dir'],
+ STDERR => 0);
+ } catch Git::Error::Command with {
+ $dir = undef;
+ };
+
+ if ($dir) {
+ $dir =~ m#^/# or $dir = $opts{Directory} . '/' . $dir;
+ $opts{Repository} = $dir;
+
+ # If --git-dir went ok, this shouldn't die either.
+ my $prefix = $search->command_oneline('rev-parse', '--show-prefix');
+ $dir = abs_path($opts{Directory}) . '/';
+ if ($prefix) {
+ if (substr($dir, -length($prefix)) ne $prefix) {
+ throw Error::Simple("rev-parse confused me - $dir does not have trailing $prefix");
+ }
+ substr($dir, -length($prefix)) = '';
+ }
+ $opts{WorkingCopy} = $dir;
+ $opts{WorkingSubdir} = $prefix;
+
+ } else {
+ # A bare repository? Let's see...
+ $dir = $opts{Directory};
+
+ unless (-d "$dir/refs" and -d "$dir/objects" and -e "$dir/HEAD") {
+ # Mimick git-rev-parse --git-dir error message:
+ throw Error::Simple('fatal: Not a git repository');
+ }
+ my $search = Git->repository(Repository => $dir);
+ try {
+ $search->command('symbolic-ref', 'HEAD');
+ } catch Git::Error::Command with {
+ # Mimick git-rev-parse --git-dir error message:
+ throw Error::Simple('fatal: Not a git repository');
+ }
+
+ $opts{Repository} = abs_path($dir);
+ }
+
+ delete $opts{Directory};
+ }
+
+ $self = { opts => \%opts };
+ bless $self, $class;
+}
+
+
+=back
+
+=head1 METHODS
+
+=over 4
+
+=item command ( COMMAND [, ARGUMENTS... ] )
+
+=item command ( [ COMMAND, ARGUMENTS... ], { Opt => Val ... } )
+
+Execute the given Git C<COMMAND> (specify it without the 'git-'
+prefix), optionally with the specified extra C<ARGUMENTS>.
+
+The second more elaborate form can be used if you want to further adjust
+the command execution. Currently, only one option is supported:
+
+B<STDERR> - How to deal with the command's error output. By default (C<undef>)
+it is delivered to the caller's C<STDERR>. A false value (0 or '') will cause
+it to be thrown away. If you want to process it, you can get it in a filehandle
+you specify, but you must be extremely careful; if the error output is not
+very short and you want to read it in the same process as where you called
+C<command()>, you are set up for a nice deadlock!
+
+The method can be called without any instance or on a specified Git repository
+(in that case the command will be run in the repository context).
+
+In scalar context, it returns all the command output in a single string
+(verbatim).
+
+In array context, it returns an array containing lines printed to the
+command's stdout (without trailing newlines).
+
+In both cases, the command's stdin and stderr are the same as the caller's.
+
+=cut
+
+sub command {
+ my ($fh, $ctx) = command_output_pipe(@_);
+
+ if (not defined wantarray) {
+ # Nothing to pepper the possible exception with.
+ _cmd_close($fh, $ctx);
+
+ } elsif (not wantarray) {
+ local $/;
+ my $text = <$fh>;
+ try {
+ _cmd_close($fh, $ctx);
+ } catch Git::Error::Command with {
+ # Pepper with the output:
+ my $E = shift;
+ $E->{'-outputref'} = \$text;
+ throw $E;
+ };
+ return $text;
+
+ } else {
+ my @lines = <$fh>;
+ defined and chomp for @lines;
+ try {
+ _cmd_close($fh, $ctx);
+ } catch Git::Error::Command with {
+ my $E = shift;
+ $E->{'-outputref'} = \@lines;
+ throw $E;
+ };
+ return @lines;
+ }
+}
+
+
+=item command_oneline ( COMMAND [, ARGUMENTS... ] )
+
+=item command_oneline ( [ COMMAND, ARGUMENTS... ], { Opt => Val ... } )
+
+Execute the given C<COMMAND> in the same way as command()
+does but always return a scalar string containing the first line
+of the command's standard output.
+
+=cut
+
+sub command_oneline {
+ my ($fh, $ctx) = command_output_pipe(@_);
+
+ my $line = <$fh>;
+ defined $line and chomp $line;
+ try {
+ _cmd_close($fh, $ctx);
+ } catch Git::Error::Command with {
+ # Pepper with the output:
+ my $E = shift;
+ $E->{'-outputref'} = \$line;
+ throw $E;
+ };
+ return $line;
+}
+
+
+=item command_output_pipe ( COMMAND [, ARGUMENTS... ] )
+
+=item command_output_pipe ( [ COMMAND, ARGUMENTS... ], { Opt => Val ... } )
+
+Execute the given C<COMMAND> in the same way as command()
+does but return a pipe filehandle from which the command output can be
+read.
+
+The function can return C<($pipe, $ctx)> in array context.
+See C<command_close_pipe()> for details.
+
+=cut
+
+sub command_output_pipe {
+ _command_common_pipe('-|', @_);
+}
+
+
+=item command_input_pipe ( COMMAND [, ARGUMENTS... ] )
+
+=item command_input_pipe ( [ COMMAND, ARGUMENTS... ], { Opt => Val ... } )
+
+Execute the given C<COMMAND> in the same way as command_output_pipe()
+does but return an input pipe filehandle instead; the command output
+is not captured.
+
+The function can return C<($pipe, $ctx)> in array context.
+See C<command_close_pipe()> for details.
+
+=cut
+
+sub command_input_pipe {
+ _command_common_pipe('|-', @_);
+}
+
+
+=item command_close_pipe ( PIPE [, CTX ] )
+
+Close the C<PIPE> as returned from C<command_*_pipe()>, checking
+whether the command finished successfully. The optional C<CTX> argument
+is required if you want to see the command name in the error message,
+and it is the second value returned by C<command_*_pipe()> when
+called in array context. The call idiom is:
+
+ my ($fh, $ctx) = $r->command_output_pipe('status');
+ while (<$fh>) { ... }
+ $r->command_close_pipe($fh, $ctx);
+
+Note that you should not rely on whatever actually is in C<CTX>;
+currently it is simply the command name but in future the context might
+have more complicated structure.
+
+=cut
+
+sub command_close_pipe {
+ my ($self, $fh, $ctx) = _maybe_self(@_);
+ $ctx ||= '<unknown>';
+ _cmd_close($fh, $ctx);
+}
+
+
+=item command_noisy ( COMMAND [, ARGUMENTS... ] )
+
+Execute the given C<COMMAND> in the same way as command() does but do not
+capture the command output - the standard output is not redirected and goes
+to the standard output of the caller application.
+
+While the method is called command_noisy(), you might want to as well use
+it for the most silent Git commands which you know will never pollute your
+stdout but you want to avoid the overhead of the pipe setup when calling them.
+
+The function returns only after the command has finished running.
+
+=cut
+
+sub command_noisy {
+ my ($self, $cmd, @args) = _maybe_self(@_);
+ _check_valid_cmd($cmd);
+
+ my $pid = fork;
+ if (not defined $pid) {
+ throw Error::Simple("fork failed: $!");
+ } elsif ($pid == 0) {
+ _cmd_exec($self, $cmd, @args);
+ }
+ if (waitpid($pid, 0) > 0 and $?>>8 != 0) {
+ throw Git::Error::Command(join(' ', $cmd, @args), $? >> 8);
+ }
+}
+
+
+=item version ()
+
+Return the Git version in use.
+
+=cut
+
+sub version {
+ my $verstr = command_oneline('--version');
+ $verstr =~ s/^git version //;
+ $verstr;
+}
+
+
+=item exec_path ()
+
+Return path to the Git sub-command executables (the same as
+C<git --exec-path>). Useful mostly only internally.
+
+=cut
+
+sub exec_path { command_oneline('--exec-path') }
+
+
+=item repo_path ()
+
+Return path to the git repository. Must be called on a repository instance.
+
+=cut
+
+sub repo_path { $_[0]->{opts}->{Repository} }
+
+
+=item wc_path ()
+
+Return path to the working copy. Must be called on a repository instance.
+
+=cut
+
+sub wc_path { $_[0]->{opts}->{WorkingCopy} }
+
+
+=item wc_subdir ()
+
+Return path to the subdirectory inside of a working copy. Must be called
+on a repository instance.
+
+=cut
+
+sub wc_subdir { $_[0]->{opts}->{WorkingSubdir} ||= '' }
+
+
+=item wc_chdir ( SUBDIR )
+
+Change the working copy subdirectory to work within. The C<SUBDIR> is
+relative to the working copy root directory (not the current subdirectory).
+Must be called on a repository instance attached to a working copy
+and the directory must exist.
+
+=cut
+
+sub wc_chdir {
+ my ($self, $subdir) = @_;
+ $self->wc_path()
+ or throw Error::Simple("bare repository");
+
+ -d $self->wc_path().'/'.$subdir
+ or throw Error::Simple("subdir not found: $!");
+ # Of course we will not "hold" the subdirectory so anyone
+ # can delete it now and we will never know. But at least we tried.
+
+ $self->{opts}->{WorkingSubdir} = $subdir;
+}
+
+
+=item config ( VARIABLE )
+
+Retrieve the configuration C<VARIABLE> in the same manner as C<config>
+does. In scalar context requires the variable to be set only one time
+(exception is thrown otherwise), in array context returns allows the
+variable to be set multiple times and returns all the values.
+
+Must be called on a repository instance.
+
+This currently wraps command('config') so it is not so fast.
+
+=cut
+
+sub config {
+ my ($self, $var) = @_;
+ $self->repo_path()
+ or throw Error::Simple("not a repository");
+
+ try {
+ if (wantarray) {
+ return $self->command('config', '--get-all', $var);
+ } else {
+ return $self->command_oneline('config', '--get', $var);
+ }
+ } catch Git::Error::Command with {
+ my $E = shift;
+ if ($E->value() == 1) {
+ # Key not found.
+ return undef;
+ } else {
+ throw $E;
+ }
+ };
+}
+
+
+=item config_bool ( VARIABLE )
+
+Retrieve the bool configuration C<VARIABLE>. The return value
+is usable as a boolean in perl (and C<undef> if it's not defined,
+of course).
+
+Must be called on a repository instance.
+
+This currently wraps command('config') so it is not so fast.
+
+=cut
+
+sub config_bool {
+ my ($self, $var) = @_;
+ $self->repo_path()
+ or throw Error::Simple("not a repository");
+
+ try {
+ my $val = $self->command_oneline('config', '--bool', '--get',
+ $var);
+ return undef unless defined $val;
+ return $val eq 'true';
+ } catch Git::Error::Command with {
+ my $E = shift;
+ if ($E->value() == 1) {
+ # Key not found.
+ return undef;
+ } else {
+ throw $E;
+ }
+ };
+}
+
+
+=item ident ( TYPE | IDENTSTR )
+
+=item ident_person ( TYPE | IDENTSTR | IDENTARRAY )
+
+This suite of functions retrieves and parses ident information, as stored
+in the commit and tag objects or produced by C<var GIT_type_IDENT> (thus
+C<TYPE> can be either I<author> or I<committer>; case is insignificant).
+
+The C<ident> method retrieves the ident information from C<git-var>
+and either returns it as a scalar string or as an array with the fields parsed.
+Alternatively, it can take a prepared ident string (e.g. from the commit
+object) and just parse it.
+
+C<ident_person> returns the person part of the ident - name and email;
+it can take the same arguments as C<ident> or the array returned by C<ident>.
+
+The synopsis is like:
+
+ my ($name, $email, $time_tz) = ident('author');
+ "$name <$email>" eq ident_person('author');
+ "$name <$email>" eq ident_person($name);
+ $time_tz =~ /^\d+ [+-]\d{4}$/;
+
+Both methods must be called on a repository instance.
+
+=cut
+
+sub ident {
+ my ($self, $type) = @_;
+ my $identstr;
+ if (lc $type eq lc 'committer' or lc $type eq lc 'author') {
+ $identstr = $self->command_oneline('var', 'GIT_'.uc($type).'_IDENT');
+ } else {
+ $identstr = $type;
+ }
+ if (wantarray) {
+ return $identstr =~ /^(.*) <(.*)> (\d+ [+-]\d{4})$/;
+ } else {
+ return $identstr;
+ }
+}
+
+sub ident_person {
+ my ($self, @ident) = @_;
+ $#ident == 0 and @ident = $self->ident($ident[0]);
+ return "$ident[0] <$ident[1]>";
+}
+
+
+=item hash_object ( TYPE, FILENAME )
+
+Compute the SHA1 object id of the given C<FILENAME> (or data waiting in
+C<FILEHANDLE>) considering it is of the C<TYPE> object type (C<blob>,
+C<commit>, C<tree>).
+
+The method can be called without any instance or on a specified Git repository,
+it makes zero difference.
+
+The function returns the SHA1 hash.
+
+=cut
+
+# TODO: Support for passing FILEHANDLE instead of FILENAME
+sub hash_object {
+ my ($self, $type, $file) = _maybe_self(@_);
+ command_oneline('hash-object', '-t', $type, $file);
+}
+
+
+
+=back
+
+=head1 ERROR HANDLING
+
+All functions are supposed to throw Perl exceptions in case of errors.
+See the L<Error> module on how to catch those. Most exceptions are mere
+L<Error::Simple> instances.
+
+However, the C<command()>, C<command_oneline()> and C<command_noisy()>
+functions suite can throw C<Git::Error::Command> exceptions as well: those are
+thrown when the external command returns an error code and contain the error
+code as well as access to the captured command's output. The exception class
+provides the usual C<stringify> and C<value> (command's exit code) methods and
+in addition also a C<cmd_output> method that returns either an array or a
+string with the captured command output (depending on the original function
+call context; C<command_noisy()> returns C<undef>) and $<cmdline> which
+returns the command and its arguments (but without proper quoting).
+
+Note that the C<command_*_pipe()> functions cannot throw this exception since
+it has no idea whether the command failed or not. You will only find out
+at the time you C<close> the pipe; if you want to have that automated,
+use C<command_close_pipe()>, which can throw the exception.
+
+=cut
+
+{
+ package Git::Error::Command;
+
+ @Git::Error::Command::ISA = qw(Error);
+
+ sub new {
+ my $self = shift;
+ my $cmdline = '' . shift;
+ my $value = 0 + shift;
+ my $outputref = shift;
+ my(@args) = ();
+
+ local $Error::Depth = $Error::Depth + 1;
+
+ push(@args, '-cmdline', $cmdline);
+ push(@args, '-value', $value);
+ push(@args, '-outputref', $outputref);
+
+ $self->SUPER::new(-text => 'command returned error', @args);
+ }
+
+ sub stringify {
+ my $self = shift;
+ my $text = $self->SUPER::stringify;
+ $self->cmdline() . ': ' . $text . ': ' . $self->value() . "\n";
+ }
+
+ sub cmdline {
+ my $self = shift;
+ $self->{'-cmdline'};
+ }
+
+ sub cmd_output {
+ my $self = shift;
+ my $ref = $self->{'-outputref'};
+ defined $ref or undef;
+ if (ref $ref eq 'ARRAY') {
+ return @$ref;
+ } else { # SCALAR
+ return $$ref;
+ }
+ }
+}
+
+=over 4
+
+=item git_cmd_try { CODE } ERRMSG
+
+This magical statement will automatically catch any C<Git::Error::Command>
+exceptions thrown by C<CODE> and make your program die with C<ERRMSG>
+on its lips; the message will have %s substituted for the command line
+and %d for the exit status. This statement is useful mostly for producing
+more user-friendly error messages.
+
+In case of no exception caught the statement returns C<CODE>'s return value.
+
+Note that this is the only auto-exported function.
+
+=cut
+
+sub git_cmd_try(&$) {
+ my ($code, $errmsg) = @_;
+ my @result;
+ my $err;
+ my $array = wantarray;
+ try {
+ if ($array) {
+ @result = &$code;
+ } else {
+ $result[0] = &$code;
+ }
+ } catch Git::Error::Command with {
+ my $E = shift;
+ $err = $errmsg;
+ $err =~ s/\%s/$E->cmdline()/ge;
+ $err =~ s/\%d/$E->value()/ge;
+ # We can't croak here since Error.pm would mangle
+ # that to Error::Simple.
+ };
+ $err and croak $err;
+ return $array ? @result : $result[0];
+}
+
+
+=back
+
+=head1 COPYRIGHT
+
+Copyright 2006 by Petr Baudis E<lt>pasky@suse.czE<gt>.
+
+This module is free software; it may be used, copied, modified
+and distributed under the terms of the GNU General Public Licence,
+either version 2, or (at your option) any later version.
+
+=cut
+
+
+# Take raw method argument list and return ($obj, @args) in case
+# the method was called upon an instance and (undef, @args) if
+# it was called directly.
+sub _maybe_self {
+ # This breaks inheritance. Oh well.
+ ref $_[0] eq 'Git' ? @_ : (undef, @_);
+}
+
+# Check if the command id is something reasonable.
+sub _check_valid_cmd {
+ my ($cmd) = @_;
+ $cmd =~ /^[a-z0-9A-Z_-]+$/ or throw Error::Simple("bad command: $cmd");
+}
+
+# Common backend for the pipe creators.
+sub _command_common_pipe {
+ my $direction = shift;
+ my ($self, @p) = _maybe_self(@_);
+ my (%opts, $cmd, @args);
+ if (ref $p[0]) {
+ ($cmd, @args) = @{shift @p};
+ %opts = ref $p[0] ? %{$p[0]} : @p;
+ } else {
+ ($cmd, @args) = @p;
+ }
+ _check_valid_cmd($cmd);
+
+ my $fh;
+ if ($^O eq 'MSWin32') {
+ # ActiveState Perl
+ #defined $opts{STDERR} and
+ # warn 'ignoring STDERR option - running w/ ActiveState';
+ $direction eq '-|' or
+ die 'input pipe for ActiveState not implemented';
+ # the strange construction with *ACPIPE is just to
+ # explain the tie below that we want to bind to
+ # a handle class, not scalar. It is not known if
+ # it is something specific to ActiveState Perl or
+ # just a Perl quirk.
+ tie (*ACPIPE, 'Git::activestate_pipe', $cmd, @args);
+ $fh = *ACPIPE;
+
+ } else {
+ my $pid = open($fh, $direction);
+ if (not defined $pid) {
+ throw Error::Simple("open failed: $!");
+ } elsif ($pid == 0) {
+ if (defined $opts{STDERR}) {
+ close STDERR;
+ }
+ if ($opts{STDERR}) {
+ open (STDERR, '>&', $opts{STDERR})
+ or die "dup failed: $!";
+ }
+ _cmd_exec($self, $cmd, @args);
+ }
+ }
+ return wantarray ? ($fh, join(' ', $cmd, @args)) : $fh;
+}
+
+# When already in the subprocess, set up the appropriate state
+# for the given repository and execute the git command.
+sub _cmd_exec {
+ my ($self, @args) = @_;
+ if ($self) {
+ $self->repo_path() and $ENV{'GIT_DIR'} = $self->repo_path();
+ $self->wc_path() and chdir($self->wc_path());
+ $self->wc_subdir() and chdir($self->wc_subdir());
+ }
+ _execv_git_cmd(@args);
+ die "exec failed: $!";
+}
+
+# Execute the given Git command ($_[0]) with arguments ($_[1..])
+# by searching for it at proper places.
+sub _execv_git_cmd { exec('git', @_); }
+
+# Close pipe to a subprocess.
+sub _cmd_close {
+ my ($fh, $ctx) = @_;
+ if (not close $fh) {
+ if ($!) {
+ # It's just close, no point in fatalities
+ carp "error closing pipe: $!";
+ } elsif ($? >> 8) {
+ # The caller should pepper this.
+ throw Git::Error::Command($ctx, $? >> 8);
+ }
+ # else we might e.g. closed a live stream; the command
+ # dying of SIGPIPE would drive us here.
+ }
+}
+
+
+sub DESTROY { }
+
+
+# Pipe implementation for ActiveState Perl.
+
+package Git::activestate_pipe;
+use strict;
+
+sub TIEHANDLE {
+ my ($class, @params) = @_;
+ # FIXME: This is probably horrible idea and the thing will explode
+ # at the moment you give it arguments that require some quoting,
+ # but I have no ActiveState clue... --pasky
+ # Let's just hope ActiveState Perl does at least the quoting
+ # correctly.
+ my @data = qx{git @params};
+ bless { i => 0, data => \@data }, $class;
+}
+
+sub READLINE {
+ my $self = shift;
+ if ($self->{i} >= scalar @{$self->{data}}) {
+ return undef;
+ }
+ return $self->{'data'}->[ $self->{i}++ ];
+}
+
+sub CLOSE {
+ my $self = shift;
+ delete $self->{data};
+ delete $self->{i};
+}
+
+sub EOF {
+ my $self = shift;
+ return ($self->{i} >= scalar @{$self->{data}});
+}
+
+
+1; # Famous last words
diff --git a/perl/Makefile b/perl/Makefile
new file mode 100644
index 0000000000..5e079ad011
--- /dev/null
+++ b/perl/Makefile
@@ -0,0 +1,42 @@
+#
+# Makefile for perl support modules and routine
+#
+makfile:=perl.mak
+
+PERL_PATH_SQ = $(subst ','\'',$(PERL_PATH))
+prefix_SQ = $(subst ','\'',$(prefix))
+
+ifndef V
+ QUIET = @
+endif
+
+all install instlibdir: $(makfile)
+ $(QUIET)$(MAKE) -f $(makfile) $@
+
+clean:
+ $(QUIET)test -f $(makfile) && $(MAKE) -f $(makfile) $@ || exit 0
+ $(RM) ppport.h
+ $(RM) $(makfile)
+ $(RM) $(makfile).old
+
+ifdef NO_PERL_MAKEMAKER
+instdir_SQ = $(subst ','\'',$(prefix)/lib)
+$(makfile): ../GIT-CFLAGS Makefile
+ echo all: > $@
+ echo ' :' >> $@
+ echo install: >> $@
+ echo ' mkdir -p $(instdir_SQ)' >> $@
+ echo ' $(RM) $(instdir_SQ)/Git.pm; cp Git.pm $(instdir_SQ)' >> $@
+ echo ' $(RM) $(instdir_SQ)/Error.pm; \
+ cp private-Error.pm $(instdir_SQ)/Error.pm' >> $@
+ echo instlibdir: >> $@
+ echo ' echo $(instdir_SQ)' >> $@
+else
+$(makfile): Makefile.PL ../GIT-CFLAGS
+ $(PERL_PATH) $< PREFIX='$(prefix_SQ)'
+endif
+
+# this is just added comfort for calling make directly in perl dir
+# (even though GIT-CFLAGS aren't used yet. If ever)
+../GIT-CFLAGS:
+ $(MAKE) -C .. GIT-CFLAGS
diff --git a/perl/Makefile.PL b/perl/Makefile.PL
new file mode 100644
index 0000000000..437516142c
--- /dev/null
+++ b/perl/Makefile.PL
@@ -0,0 +1,33 @@
+use ExtUtils::MakeMaker;
+
+sub MY::postamble {
+ return <<'MAKE_FRAG';
+instlibdir:
+ @echo '$(INSTALLSITELIB)'
+
+MAKE_FRAG
+}
+
+my %pm = ('Git.pm' => '$(INST_LIBDIR)/Git.pm');
+
+# We come with our own bundled Error.pm. It's not in the set of default
+# Perl modules so install it if it's not available on the system yet.
+eval { require Error };
+if ($@ || $Error::VERSION < 0.15009) {
+ $pm{'private-Error.pm'} = '$(INST_LIBDIR)/Error.pm';
+}
+
+my %extra;
+$extra{DESTDIR} = $ENV{DESTDIR} if $ENV{DESTDIR};
+
+# redirect stdout, otherwise the message "Writing perl.mak for Git"
+# disrupts the output for the target 'instlibdir'
+open STDOUT, ">&STDERR";
+
+WriteMakefile(
+ NAME => 'Git',
+ VERSION_FROM => 'Git.pm',
+ PM => \%pm,
+ MAKEFILE => 'perl.mak',
+ %extra
+);
diff --git a/perl/private-Error.pm b/perl/private-Error.pm
new file mode 100644
index 0000000000..11e9cd9a02
--- /dev/null
+++ b/perl/private-Error.pm
@@ -0,0 +1,827 @@
+# Error.pm
+#
+# Copyright (c) 1997-8 Graham Barr <gbarr@ti.com>. All rights reserved.
+# This program is free software; you can redistribute it and/or
+# modify it under the same terms as Perl itself.
+#
+# Based on my original Error.pm, and Exceptions.pm by Peter Seibel
+# <peter@weblogic.com> and adapted by Jesse Glick <jglick@sig.bsh.com>.
+#
+# but modified ***significantly***
+
+package Error;
+
+use strict;
+use vars qw($VERSION);
+use 5.004;
+
+$VERSION = "0.15009";
+
+use overload (
+ '""' => 'stringify',
+ '0+' => 'value',
+ 'bool' => sub { return 1; },
+ 'fallback' => 1
+);
+
+$Error::Depth = 0; # Depth to pass to caller()
+$Error::Debug = 0; # Generate verbose stack traces
+@Error::STACK = (); # Clause stack for try
+$Error::THROWN = undef; # last error thrown, a workaround until die $ref works
+
+my $LAST; # Last error created
+my %ERROR; # Last error associated with package
+
+sub throw_Error_Simple
+{
+ my $args = shift;
+ return Error::Simple->new($args->{'text'});
+}
+
+$Error::ObjectifyCallback = \&throw_Error_Simple;
+
+
+# Exported subs are defined in Error::subs
+
+sub import {
+ shift;
+ local $Exporter::ExportLevel = $Exporter::ExportLevel + 1;
+ Error::subs->import(@_);
+}
+
+# I really want to use last for the name of this method, but it is a keyword
+# which prevent the syntax last Error
+
+sub prior {
+ shift; # ignore
+
+ return $LAST unless @_;
+
+ my $pkg = shift;
+ return exists $ERROR{$pkg} ? $ERROR{$pkg} : undef
+ unless ref($pkg);
+
+ my $obj = $pkg;
+ my $err = undef;
+ if($obj->isa('HASH')) {
+ $err = $obj->{'__Error__'}
+ if exists $obj->{'__Error__'};
+ }
+ elsif($obj->isa('GLOB')) {
+ $err = ${*$obj}{'__Error__'}
+ if exists ${*$obj}{'__Error__'};
+ }
+
+ $err;
+}
+
+sub flush {
+ shift; #ignore
+
+ unless (@_) {
+ $LAST = undef;
+ return;
+ }
+
+ my $pkg = shift;
+ return unless ref($pkg);
+
+ undef $ERROR{$pkg} if defined $ERROR{$pkg};
+}
+
+# Return as much information as possible about where the error
+# happened. The -stacktrace element only exists if $Error::DEBUG
+# was set when the error was created
+
+sub stacktrace {
+ my $self = shift;
+
+ return $self->{'-stacktrace'}
+ if exists $self->{'-stacktrace'};
+
+ my $text = exists $self->{'-text'} ? $self->{'-text'} : "Died";
+
+ $text .= sprintf(" at %s line %d.\n", $self->file, $self->line)
+ unless($text =~ /\n$/s);
+
+ $text;
+}
+
+# Allow error propagation, ie
+#
+# $ber->encode(...) or
+# return Error->prior($ber)->associate($ldap);
+
+sub associate {
+ my $err = shift;
+ my $obj = shift;
+
+ return unless ref($obj);
+
+ if($obj->isa('HASH')) {
+ $obj->{'__Error__'} = $err;
+ }
+ elsif($obj->isa('GLOB')) {
+ ${*$obj}{'__Error__'} = $err;
+ }
+ $obj = ref($obj);
+ $ERROR{ ref($obj) } = $err;
+
+ return;
+}
+
+sub new {
+ my $self = shift;
+ my($pkg,$file,$line) = caller($Error::Depth);
+
+ my $err = bless {
+ '-package' => $pkg,
+ '-file' => $file,
+ '-line' => $line,
+ @_
+ }, $self;
+
+ $err->associate($err->{'-object'})
+ if(exists $err->{'-object'});
+
+ # To always create a stacktrace would be very inefficient, so
+ # we only do it if $Error::Debug is set
+
+ if($Error::Debug) {
+ require Carp;
+ local $Carp::CarpLevel = $Error::Depth;
+ my $text = defined($err->{'-text'}) ? $err->{'-text'} : "Error";
+ my $trace = Carp::longmess($text);
+ # Remove try calls from the trace
+ $trace =~ s/(\n\s+\S+__ANON__[^\n]+)?\n\s+eval[^\n]+\n\s+Error::subs::try[^\n]+(?=\n)//sog;
+ $trace =~ s/(\n\s+\S+__ANON__[^\n]+)?\n\s+eval[^\n]+\n\s+Error::subs::run_clauses[^\n]+\n\s+Error::subs::try[^\n]+(?=\n)//sog;
+ $err->{'-stacktrace'} = $trace
+ }
+
+ $@ = $LAST = $ERROR{$pkg} = $err;
+}
+
+# Throw an error. this contains some very gory code.
+
+sub throw {
+ my $self = shift;
+ local $Error::Depth = $Error::Depth + 1;
+
+ # if we are not rethrow-ing then create the object to throw
+ $self = $self->new(@_) unless ref($self);
+
+ die $Error::THROWN = $self;
+}
+
+# syntactic sugar for
+#
+# die with Error( ... );
+
+sub with {
+ my $self = shift;
+ local $Error::Depth = $Error::Depth + 1;
+
+ $self->new(@_);
+}
+
+# syntactic sugar for
+#
+# record Error( ... ) and return;
+
+sub record {
+ my $self = shift;
+ local $Error::Depth = $Error::Depth + 1;
+
+ $self->new(@_);
+}
+
+# catch clause for
+#
+# try { ... } catch CLASS with { ... }
+
+sub catch {
+ my $pkg = shift;
+ my $code = shift;
+ my $clauses = shift || {};
+ my $catch = $clauses->{'catch'} ||= [];
+
+ unshift @$catch, $pkg, $code;
+
+ $clauses;
+}
+
+# Object query methods
+
+sub object {
+ my $self = shift;
+ exists $self->{'-object'} ? $self->{'-object'} : undef;
+}
+
+sub file {
+ my $self = shift;
+ exists $self->{'-file'} ? $self->{'-file'} : undef;
+}
+
+sub line {
+ my $self = shift;
+ exists $self->{'-line'} ? $self->{'-line'} : undef;
+}
+
+sub text {
+ my $self = shift;
+ exists $self->{'-text'} ? $self->{'-text'} : undef;
+}
+
+# overload methods
+
+sub stringify {
+ my $self = shift;
+ defined $self->{'-text'} ? $self->{'-text'} : "Died";
+}
+
+sub value {
+ my $self = shift;
+ exists $self->{'-value'} ? $self->{'-value'} : undef;
+}
+
+package Error::Simple;
+
+@Error::Simple::ISA = qw(Error);
+
+sub new {
+ my $self = shift;
+ my $text = "" . shift;
+ my $value = shift;
+ my(@args) = ();
+
+ local $Error::Depth = $Error::Depth + 1;
+
+ @args = ( -file => $1, -line => $2)
+ if($text =~ s/\s+at\s+(\S+)\s+line\s+(\d+)(?:,\s*<[^>]*>\s+line\s+\d+)?\.?\n?$//s);
+ push(@args, '-value', 0 + $value)
+ if defined($value);
+
+ $self->SUPER::new(-text => $text, @args);
+}
+
+sub stringify {
+ my $self = shift;
+ my $text = $self->SUPER::stringify;
+ $text .= sprintf(" at %s line %d.\n", $self->file, $self->line)
+ unless($text =~ /\n$/s);
+ $text;
+}
+
+##########################################################################
+##########################################################################
+
+# Inspired by code from Jesse Glick <jglick@sig.bsh.com> and
+# Peter Seibel <peter@weblogic.com>
+
+package Error::subs;
+
+use Exporter ();
+use vars qw(@EXPORT_OK @ISA %EXPORT_TAGS);
+
+@EXPORT_OK = qw(try with finally except otherwise);
+%EXPORT_TAGS = (try => \@EXPORT_OK);
+
+@ISA = qw(Exporter);
+
+
+sub blessed {
+ my $item = shift;
+ local $@; # don't kill an outer $@
+ ref $item and eval { $item->can('can') };
+}
+
+
+sub run_clauses ($$$\@) {
+ my($clauses,$err,$wantarray,$result) = @_;
+ my $code = undef;
+
+ $err = $Error::ObjectifyCallback->({'text' =>$err}) unless ref($err);
+
+ CATCH: {
+
+ # catch
+ my $catch;
+ if(defined($catch = $clauses->{'catch'})) {
+ my $i = 0;
+
+ CATCHLOOP:
+ for( ; $i < @$catch ; $i += 2) {
+ my $pkg = $catch->[$i];
+ unless(defined $pkg) {
+ #except
+ splice(@$catch,$i,2,$catch->[$i+1]->());
+ $i -= 2;
+ next CATCHLOOP;
+ }
+ elsif(blessed($err) && $err->isa($pkg)) {
+ $code = $catch->[$i+1];
+ while(1) {
+ my $more = 0;
+ local($Error::THROWN);
+ my $ok = eval {
+ if($wantarray) {
+ @{$result} = $code->($err,\$more);
+ }
+ elsif(defined($wantarray)) {
+ @{$result} = ();
+ $result->[0] = $code->($err,\$more);
+ }
+ else {
+ $code->($err,\$more);
+ }
+ 1;
+ };
+ if( $ok ) {
+ next CATCHLOOP if $more;
+ undef $err;
+ }
+ else {
+ $err = defined($Error::THROWN)
+ ? $Error::THROWN : $@;
+ $err = $Error::ObjectifyCallback->({'text' =>$err})
+ unless ref($err);
+ }
+ last CATCH;
+ };
+ }
+ }
+ }
+
+ # otherwise
+ my $owise;
+ if(defined($owise = $clauses->{'otherwise'})) {
+ my $code = $clauses->{'otherwise'};
+ my $more = 0;
+ my $ok = eval {
+ if($wantarray) {
+ @{$result} = $code->($err,\$more);
+ }
+ elsif(defined($wantarray)) {
+ @{$result} = ();
+ $result->[0] = $code->($err,\$more);
+ }
+ else {
+ $code->($err,\$more);
+ }
+ 1;
+ };
+ if( $ok ) {
+ undef $err;
+ }
+ else {
+ $err = defined($Error::THROWN)
+ ? $Error::THROWN : $@;
+
+ $err = $Error::ObjectifyCallback->({'text' =>$err})
+ unless ref($err);
+ }
+ }
+ }
+ $err;
+}
+
+sub try (&;$) {
+ my $try = shift;
+ my $clauses = @_ ? shift : {};
+ my $ok = 0;
+ my $err = undef;
+ my @result = ();
+
+ unshift @Error::STACK, $clauses;
+
+ my $wantarray = wantarray();
+
+ do {
+ local $Error::THROWN = undef;
+ local $@ = undef;
+
+ $ok = eval {
+ if($wantarray) {
+ @result = $try->();
+ }
+ elsif(defined $wantarray) {
+ $result[0] = $try->();
+ }
+ else {
+ $try->();
+ }
+ 1;
+ };
+
+ $err = defined($Error::THROWN) ? $Error::THROWN : $@
+ unless $ok;
+ };
+
+ shift @Error::STACK;
+
+ $err = run_clauses($clauses,$err,wantarray,@result)
+ unless($ok);
+
+ $clauses->{'finally'}->()
+ if(defined($clauses->{'finally'}));
+
+ if (defined($err))
+ {
+ if (blessed($err) && $err->can('throw'))
+ {
+ throw $err;
+ }
+ else
+ {
+ die $err;
+ }
+ }
+
+ wantarray ? @result : $result[0];
+}
+
+# Each clause adds a sub to the list of clauses. The finally clause is
+# always the last, and the otherwise clause is always added just before
+# the finally clause.
+#
+# All clauses, except the finally clause, add a sub which takes one argument
+# this argument will be the error being thrown. The sub will return a code ref
+# if that clause can handle that error, otherwise undef is returned.
+#
+# The otherwise clause adds a sub which unconditionally returns the users
+# code reference, this is why it is forced to be last.
+#
+# The catch clause is defined in Error.pm, as the syntax causes it to
+# be called as a method
+
+sub with (&;$) {
+ @_
+}
+
+sub finally (&) {
+ my $code = shift;
+ my $clauses = { 'finally' => $code };
+ $clauses;
+}
+
+# The except clause is a block which returns a hashref or a list of
+# key-value pairs, where the keys are the classes and the values are subs.
+
+sub except (&;$) {
+ my $code = shift;
+ my $clauses = shift || {};
+ my $catch = $clauses->{'catch'} ||= [];
+
+ my $sub = sub {
+ my $ref;
+ my(@array) = $code->($_[0]);
+ if(@array == 1 && ref($array[0])) {
+ $ref = $array[0];
+ $ref = [ %$ref ]
+ if(UNIVERSAL::isa($ref,'HASH'));
+ }
+ else {
+ $ref = \@array;
+ }
+ @$ref
+ };
+
+ unshift @{$catch}, undef, $sub;
+
+ $clauses;
+}
+
+sub otherwise (&;$) {
+ my $code = shift;
+ my $clauses = shift || {};
+
+ if(exists $clauses->{'otherwise'}) {
+ require Carp;
+ Carp::croak("Multiple otherwise clauses");
+ }
+
+ $clauses->{'otherwise'} = $code;
+
+ $clauses;
+}
+
+1;
+__END__
+
+=head1 NAME
+
+Error - Error/exception handling in an OO-ish way
+
+=head1 SYNOPSIS
+
+ use Error qw(:try);
+
+ throw Error::Simple( "A simple error");
+
+ sub xyz {
+ ...
+ record Error::Simple("A simple error")
+ and return;
+ }
+
+ unlink($file) or throw Error::Simple("$file: $!",$!);
+
+ try {
+ do_some_stuff();
+ die "error!" if $condition;
+ throw Error::Simple -text => "Oops!" if $other_condition;
+ }
+ catch Error::IO with {
+ my $E = shift;
+ print STDERR "File ", $E->{'-file'}, " had a problem\n";
+ }
+ except {
+ my $E = shift;
+ my $general_handler=sub {send_message $E->{-description}};
+ return {
+ UserException1 => $general_handler,
+ UserException2 => $general_handler
+ };
+ }
+ otherwise {
+ print STDERR "Well I don't know what to say\n";
+ }
+ finally {
+ close_the_garage_door_already(); # Should be reliable
+ }; # Don't forget the trailing ; or you might be surprised
+
+=head1 DESCRIPTION
+
+The C<Error> package provides two interfaces. Firstly C<Error> provides
+a procedural interface to exception handling. Secondly C<Error> is a
+base class for errors/exceptions that can either be thrown, for
+subsequent catch, or can simply be recorded.
+
+Errors in the class C<Error> should not be thrown directly, but the
+user should throw errors from a sub-class of C<Error>.
+
+=head1 PROCEDURAL INTERFACE
+
+C<Error> exports subroutines to perform exception handling. These will
+be exported if the C<:try> tag is used in the C<use> line.
+
+=over 4
+
+=item try BLOCK CLAUSES
+
+C<try> is the main subroutine called by the user. All other subroutines
+exported are clauses to the try subroutine.
+
+The BLOCK will be evaluated and, if no error is throw, try will return
+the result of the block.
+
+C<CLAUSES> are the subroutines below, which describe what to do in the
+event of an error being thrown within BLOCK.
+
+=item catch CLASS with BLOCK
+
+This clauses will cause all errors that satisfy C<$err-E<gt>isa(CLASS)>
+to be caught and handled by evaluating C<BLOCK>.
+
+C<BLOCK> will be passed two arguments. The first will be the error
+being thrown. The second is a reference to a scalar variable. If this
+variable is set by the catch block then, on return from the catch
+block, try will continue processing as if the catch block was never
+found.
+
+To propagate the error the catch block may call C<$err-E<gt>throw>
+
+If the scalar reference by the second argument is not set, and the
+error is not thrown. Then the current try block will return with the
+result from the catch block.
+
+=item except BLOCK
+
+When C<try> is looking for a handler, if an except clause is found
+C<BLOCK> is evaluated. The return value from this block should be a
+HASHREF or a list of key-value pairs, where the keys are class names
+and the values are CODE references for the handler of errors of that
+type.
+
+=item otherwise BLOCK
+
+Catch any error by executing the code in C<BLOCK>
+
+When evaluated C<BLOCK> will be passed one argument, which will be the
+error being processed.
+
+Only one otherwise block may be specified per try block
+
+=item finally BLOCK
+
+Execute the code in C<BLOCK> either after the code in the try block has
+successfully completed, or if the try block throws an error then
+C<BLOCK> will be executed after the handler has completed.
+
+If the handler throws an error then the error will be caught, the
+finally block will be executed and the error will be re-thrown.
+
+Only one finally block may be specified per try block
+
+=back
+
+=head1 CLASS INTERFACE
+
+=head2 CONSTRUCTORS
+
+The C<Error> object is implemented as a HASH. This HASH is initialized
+with the arguments that are passed to it's constructor. The elements
+that are used by, or are retrievable by the C<Error> class are listed
+below, other classes may add to these.
+
+ -file
+ -line
+ -text
+ -value
+ -object
+
+If C<-file> or C<-line> are not specified in the constructor arguments
+then these will be initialized with the file name and line number where
+the constructor was called from.
+
+If the error is associated with an object then the object should be
+passed as the C<-object> argument. This will allow the C<Error> package
+to associate the error with the object.
+
+The C<Error> package remembers the last error created, and also the
+last error associated with a package. This could either be the last
+error created by a sub in that package, or the last error which passed
+an object blessed into that package as the C<-object> argument.
+
+=over 4
+
+=item throw ( [ ARGS ] )
+
+Create a new C<Error> object and throw an error, which will be caught
+by a surrounding C<try> block, if there is one. Otherwise it will cause
+the program to exit.
+
+C<throw> may also be called on an existing error to re-throw it.
+
+=item with ( [ ARGS ] )
+
+Create a new C<Error> object and returns it. This is defined for
+syntactic sugar, eg
+
+ die with Some::Error ( ... );
+
+=item record ( [ ARGS ] )
+
+Create a new C<Error> object and returns it. This is defined for
+syntactic sugar, eg
+
+ record Some::Error ( ... )
+ and return;
+
+=back
+
+=head2 STATIC METHODS
+
+=over 4
+
+=item prior ( [ PACKAGE ] )
+
+Return the last error created, or the last error associated with
+C<PACKAGE>
+
+=item flush ( [ PACKAGE ] )
+
+Flush the last error created, or the last error associated with
+C<PACKAGE>.It is necessary to clear the error stack before exiting the
+package or uncaught errors generated using C<record> will be reported.
+
+ $Error->flush;
+
+=cut
+
+=back
+
+=head2 OBJECT METHODS
+
+=over 4
+
+=item stacktrace
+
+If the variable C<$Error::Debug> was non-zero when the error was
+created, then C<stacktrace> returns a string created by calling
+C<Carp::longmess>. If the variable was zero the C<stacktrace> returns
+the text of the error appended with the filename and line number of
+where the error was created, providing the text does not end with a
+newline.
+
+=item object
+
+The object this error was associated with
+
+=item file
+
+The file where the constructor of this error was called from
+
+=item line
+
+The line where the constructor of this error was called from
+
+=item text
+
+The text of the error
+
+=back
+
+=head2 OVERLOAD METHODS
+
+=over 4
+
+=item stringify
+
+A method that converts the object into a string. This method may simply
+return the same as the C<text> method, or it may append more
+information. For example the file name and line number.
+
+By default this method returns the C<-text> argument that was passed to
+the constructor, or the string C<"Died"> if none was given.
+
+=item value
+
+A method that will return a value that can be associated with the
+error. For example if an error was created due to the failure of a
+system call, then this may return the numeric value of C<$!> at the
+time.
+
+By default this method returns the C<-value> argument that was passed
+to the constructor.
+
+=back
+
+=head1 PRE-DEFINED ERROR CLASSES
+
+=over 4
+
+=item Error::Simple
+
+This class can be used to hold simple error strings and values. It's
+constructor takes two arguments. The first is a text value, the second
+is a numeric value. These values are what will be returned by the
+overload methods.
+
+If the text value ends with C<at file line 1> as $@ strings do, then
+this infomation will be used to set the C<-file> and C<-line> arguments
+of the error object.
+
+This class is used internally if an eval'd block die's with an error
+that is a plain string. (Unless C<$Error::ObjectifyCallback> is modified)
+
+=back
+
+=head1 $Error::ObjectifyCallback
+
+This variable holds a reference to a subroutine that converts errors that
+are plain strings to objects. It is used by Error.pm to convert textual
+errors to objects, and can be overridden by the user.
+
+It accepts a single argument which is a hash reference to named parameters.
+Currently the only named parameter passed is C<'text'> which is the text
+of the error, but others may be available in the future.
+
+For example the following code will cause Error.pm to throw objects of the
+class MyError::Bar by default:
+
+ sub throw_MyError_Bar
+ {
+ my $args = shift;
+ my $err = MyError::Bar->new();
+ $err->{'MyBarText'} = $args->{'text'};
+ return $err;
+ }
+
+ {
+ local $Error::ObjectifyCallback = \&throw_MyError_Bar;
+
+ # Error handling here.
+ }
+
+=head1 KNOWN BUGS
+
+None, but that does not mean there are not any.
+
+=head1 AUTHORS
+
+Graham Barr <gbarr@pobox.com>
+
+The code that inspired me to write this was originally written by
+Peter Seibel <peter@weblogic.com> and adapted by Jesse Glick
+<jglick@sig.bsh.com>.
+
+=head1 MAINTAINER
+
+Shlomi Fish <shlomif@iglu.org.il>
+
+=head1 PAST MAINTAINERS
+
+Arun Kumar U <u_arunkumar@yahoo.com>
+
+=cut