Git(3) User Contributed Perl Documentation Git(3)
NAME
Git - Perl interface to the Git version control system
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 );
my $sha1 = $repo->hash_and_insert_object('file.txt');
my $tempfile = tempfile();
my $size = $repo->cat_blob($sha1, $tempfile);
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 "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 increase notwithstanding).
CONSTRUCTORS
repository ( OPTIONS )
repository ( DIRECTORY )
repository ()
Construct a new repository object. "OPTIONS" are passed in a hash
like fashion, using key and value pairs. Possible options are:
Repository - Path to the Git repository.
WorkingCopy - Path to the associated working copy; not strictly
required as many commands will happily crunch on a bare repository.
WorkingSubdir - Subdirectory in the working copy to work inside.
Just left undefined if you do not want to limit the scope of
operations.
Directory - Path to the Git working directory in its usual setup.
The ".git" directory is searched in the directory and all the
parent directories; if found, "WorkingCopy" is set to the directory
containing it and "Repository" to the ".git" directory itself. If
no ".git" directory was found, the "Directory" is assumed to be a
bare repository, "Repository" is set to point at it and
"WorkingCopy" is left undefined. If the $GIT_DIR environment
variable is set, things behave as expected as well.
You should not use both "Directory" and either of "Repository" and
"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
"Directory" option field.
Calling the constructor with no options whatsoever is equivalent to
calling it with "Directory => '.'". In general, if you are building
a standard porcelain command, simply doing "Git->repository()"
should do the right thing and setup the object to reflect exactly
where the user is right now.
METHODS
command ( COMMAND [, ARGUMENTS... ] )
command ( [ COMMAND, ARGUMENTS... ], { Opt => Val ... } )
Execute the given Git "COMMAND" (specify it without the 'git-'
prefix), optionally with the specified extra "ARGUMENTS".
The second more elaborate form can be used if you want to further
adjust the command execution. Currently, only one option is
supported:
STDERR - How to deal with the command's error output. By default
("undef") it is delivered to the caller's "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
"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.
command_oneline ( COMMAND [, ARGUMENTS... ] )
command_oneline ( [ COMMAND, ARGUMENTS... ], { Opt => Val ... } )
Execute the given "COMMAND" in the same way as command() does but
always return a scalar string containing the first line of the
command's standard output.
command_output_pipe ( COMMAND [, ARGUMENTS... ] )
command_output_pipe ( [ COMMAND, ARGUMENTS... ], { Opt => Val ... } )
Execute the given "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 "($pipe, $ctx)" in array context. See
"command_close_pipe()" for details.
command_input_pipe ( COMMAND [, ARGUMENTS... ] )
command_input_pipe ( [ COMMAND, ARGUMENTS... ], { Opt => Val ... } )
Execute the given "COMMAND" in the same way as
command_output_pipe() does but return an input pipe filehandle
instead; the command output is not captured.
The function can return "($pipe, $ctx)" in array context. See
"command_close_pipe()" for details.
command_close_pipe ( PIPE [, CTX ] )
Close the "PIPE" as returned from "command_*_pipe()", checking
whether the command finished successfully. The optional "CTX"
argument is required if you want to see the command name in the
error message, and it is the second value returned by
"command_*_pipe()" when called in array context. The call idiom is:
my ($fh, $ctx) = $r->command_output_pipe('status');
while (<$fh>) { ... }
$r->command_close_pipe($fh, $ctx);
Note that you should not rely on whatever actually is in "CTX";
currently it is simply the command name but in future the context
might have more complicated structure.
command_bidi_pipe ( COMMAND [, ARGUMENTS... ] )
Execute the given "COMMAND" in the same way as
command_output_pipe() does but return both an input pipe filehandle
and an output pipe filehandle.
The function will return return "($pid, $pipe_in, $pipe_out,
$ctx)". See "command_close_bidi_pipe()" for details.
command_close_bidi_pipe ( PID, PIPE_IN, PIPE_OUT [, CTX] )
Close the "PIPE_IN" and "PIPE_OUT" as returned from
"command_bidi_pipe()", checking whether the command finished
successfully. The optional "CTX" argument is required if you want
to see the command name in the error message, and it is the fourth
value returned by "command_bidi_pipe()". The call idiom is:
my ($pid, $in, $out, $ctx) = $r->command_bidi_pipe('cat-file --batch-check');
print $out "000000000\n";
while (<$in>) { ... }
$r->command_close_bidi_pipe($pid, $in, $out, $ctx);
Note that you should not rely on whatever actually is in "CTX";
currently it is simply the command name but in future the context
might have more complicated structure.
"PIPE_IN" and "PIPE_OUT" may be "undef" if they have been closed
prior to calling this function. This may be useful in a query-
response type of commands where caller first writes a query and
later reads response, eg:
my ($pid, $in, $out, $ctx) = $r->command_bidi_pipe('cat-file --batch-check');
print $out "000000000\n";
close $out;
while (<$in>) { ... }
$r->command_close_bidi_pipe($pid, $in, undef, $ctx);
This idiom may prevent potential dead locks caused by data sent to
the output pipe not being flushed and thus not reaching the
executed command.
command_noisy ( COMMAND [, ARGUMENTS... ] )
Execute the given "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.
version ()
Return the Git version in use.
exec_path ()
Return path to the Git sub-command executables (the same as "git
--exec-path"). Useful mostly only internally.
html_path ()
Return path to the Git html documentation (the same as "git
--html-path"). Useful mostly only internally.
get_tz_offset ( TIME )
Return the time zone offset from GMT in the form +/-HHMM where HH
is the number of hours from GMT and MM is the number of minutes.
This is the equivalent of what strftime("%z", ...) would provide on
a GNU platform.
If TIME is not supplied, the current local time is used.
prompt ( PROMPT , ISPASSWORD )
Query user "PROMPT" and return answer from user.
Honours GIT_ASKPASS and SSH_ASKPASS environment variables for
querying the user. If no *_ASKPASS variable is set or an error
occoured, the terminal is tried as a fallback. If "ISPASSWORD" is
set and true, the terminal disables echo.
repo_path ()
Return path to the git repository. Must be called on a repository
instance.
wc_path ()
Return path to the working copy. Must be called on a repository
instance.
wc_subdir ()
Return path to the subdirectory inside of a working copy. Must be
called on a repository instance.
wc_chdir ( SUBDIR )
Change the working copy subdirectory to work within. The "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.
config ( VARIABLE )
Retrieve the configuration "VARIABLE" in the same manner as
"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.
config_bool ( VARIABLE )
Retrieve the bool configuration "VARIABLE". The return value is
usable as a boolean in perl (and "undef" if it's not defined, of
course).
config_path ( VARIABLE )
Retrieve the path configuration "VARIABLE". The return value is an
expanded path or "undef" if it's not defined.
config_int ( VARIABLE )
Retrieve the integer configuration "VARIABLE". The return value is
simple decimal number. An optional value suffix of 'k', 'm', or
'g' in the config file will cause the value to be multiplied by
1024, 1048576 (1024^2), or 1073741824 (1024^3) prior to output. It
would return "undef" if configuration variable is not defined,
get_colorbool ( NAME )
Finds if color should be used for NAMEd operation from the
configuration, and returns boolean (true for "use color", false for
"do not use color").
get_color ( SLOT, COLOR )
Finds color for SLOT from the configuration, while defaulting to
COLOR, and returns the ANSI color escape sequence:
print $repo->get_color("color.interactive.prompt", "underline blue white");
print "some text";
print $repo->get_color("", "normal");
remote_refs ( REPOSITORY [, GROUPS [, REFGLOBS ] ] )
This function returns a hashref of refs stored in a given remote
repository. The hash is in the format "refname =\" hash>. For
tags, the "refname" entry contains the tag object while a
"refname^{}" entry gives the tagged objects.
"REPOSITORY" has the same meaning as the appropriate
"git-ls-remote" argument; either a URL or a remote name (if called
on a repository instance). "GROUPS" is an optional arrayref that
can contain 'tags' to return all the tags and/or 'heads' to return
all the heads. "REFGLOB" is an optional array of strings containing
a shell-like glob to further limit the refs returned in the hash;
the meaning is again the same as the appropriate "git-ls-remote"
argument.
This function may or may not be called on a repository instance. In
the former case, remote names as defined in the repository are
recognized as repository specifiers.
ident ( TYPE | IDENTSTR )
ident_person ( TYPE | IDENTSTR | IDENTARRAY )
This suite of functions retrieves and parses ident information, as
stored in the commit and tag objects or produced by "var
GIT_type_IDENT" (thus "TYPE" can be either author or committer;
case is insignificant).
The "ident" method retrieves the ident information from "git var"
and either returns it as a scalar string or as an array with the
fields parsed. Alternatively, it can take a prepared ident string
(e.g. from the commit object) and just parse it.
"ident_person" returns the person part of the ident - name and
email; it can take the same arguments as "ident" or the array
returned by "ident".
The synopsis is like:
my ($name, $email, $time_tz) = ident('author');
"$name <$email>" eq ident_person('author');
"$name <$email>" eq ident_person($name);
$time_tz =~ /^\d+ [+-]\d{4}$/;
hash_object ( TYPE, FILENAME )
Compute the SHA1 object id of the given "FILENAME" considering it
is of the "TYPE" object type ("blob", "commit", "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.
hash_and_insert_object ( FILENAME )
Compute the SHA1 object id of the given "FILENAME" and add the
object to the object database.
The function returns the SHA1 hash.
cat_blob ( SHA1, FILEHANDLE )
Prints the contents of the blob identified by "SHA1" to
"FILEHANDLE" and returns the number of bytes printed.
credential_read( FILEHANDLE )
Reads credential key-value pairs from "FILEHANDLE". Reading stops
at EOF or when an empty line is encountered. Each line must be of
the form "key=value" with a non-empty key. Function returns hash
with all read values. Any white space (other than new-line
character) is preserved.
credential_write( FILEHANDLE, CREDENTIAL_HASHREF )
Writes credential key-value pairs from hash referenced by
"CREDENTIAL_HASHREF" to "FILEHANDLE". Keys and values cannot
contain new-lines or NUL bytes characters, and key cannot contain
equal signs nor be empty (if they do Error::Simple is thrown). Any
white space is preserved. If value for a key is "undef", it will
be skipped.
If 'url' key exists it will be written first. (All the other key-
value pairs are written in sorted order but you should not depend
on that). Once all lines are written, an empty line is printed.
credential( CREDENTIAL_HASHREF [, OPERATION ] )
credential( CREDENTIAL_HASHREF, CODE )
Executes "git credential" for a given set of credentials and
specified operation. In both forms "CREDENTIAL_HASHREF" needs to
be a reference to a hash which stores credentials. Under certain
conditions the hash can change.
In the first form, "OPERATION" can be 'fill', 'approve' or
'reject', and function will execute corresponding "git credential"
sub-command. If it's omitted 'fill' is assumed. In case of 'fill'
the values stored in "CREDENTIAL_HASHREF" will be changed to the
ones returned by the "git credential fill" command. The usual
usage would look something like:
my %cred = (
'protocol' => 'https',
'host' => 'example.com',
'username' => 'bob'
);
Git::credential \%cred;
if (try_to_authenticate($cred{'username'}, $cred{'password'})) {
Git::credential \%cred, 'approve';
... do more stuff ...
} else {
Git::credential \%cred, 'reject';
}
In the second form, "CODE" needs to be a reference to a subroutine.
The function will execute "git credential fill" to fill the
provided credential hash, then call "CODE" with
"CREDENTIAL_HASHREF" as the sole argument. If "CODE"'s return
value is defined, the function will execute "git credential
approve" (if return value yields true) or "git credential reject"
(if return value is false). If the return value is undef, nothing
at all is executed; this is useful, for example, if the credential
could neither be verified nor rejected due to an unrelated network
error. The return value is the same as what "CODE" returns. With
this form, the usage might look as follows:
if (Git::credential {
'protocol' => 'https',
'host' => 'example.com',
'username' => 'bob'
}, sub {
my $cred = shift;
return !!try_to_authenticate($cred->{'username'},
$cred->{'password'});
}) {
... do more stuff ...
}
temp_acquire ( NAME )
Attempts to retrieve the temporary file mapped to the string
"NAME". If an associated temp file has not been created this
session or was closed, it is created, cached, and set for autoflush
and binmode.
Internally locks the file mapped to "NAME". This lock must be
released with "temp_release()" when the temp file is no longer
needed. Subsequent attempts to retrieve temporary files mapped to
the same "NAME" while still locked will cause an error. This
locking mechanism provides a weak guarantee and is not threadsafe.
It does provide some error checking to help prevent temp file refs
writing over one another.
In general, the File::Handle returned should not be closed by
consumers as it defeats the purpose of this caching mechanism. If
you need to close the temp file handle, then you should use
File::Temp or another temp file faculty directly. If a handle is
closed and then requested again, then a warning will issue.
temp_release ( NAME )
temp_release ( FILEHANDLE )
Releases a lock acquired through "temp_acquire()". Can be called
either with the "NAME" mapping used when acquiring the temp file or
with the "FILEHANDLE" referencing a locked temp file.
Warns if an attempt is made to release a file that is not locked.
The temp file will be truncated before being released. This can
help to reduce disk I/O where the system is smart enough to detect
the truncation while data is in the output buffers. Beware that
after the temp file is released and truncated, any operations on
that file may fail miserably until it is re-acquired. All contents
are lost between each release and acquire mapped to the same
string.
temp_reset ( FILEHANDLE )
Truncates and resets the position of the "FILEHANDLE".
temp_path ( NAME )
temp_path ( FILEHANDLE )
Returns the filename associated with the given tempfile.
ERROR HANDLING
All functions are supposed to throw Perl exceptions in case of errors.
See the Error module on how to catch those. Most exceptions are mere
Error::Simple instances.
However, the "command()", "command_oneline()" and "command_noisy()"
functions suite can throw "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 "stringify" and "value"
(command's exit code) methods and in addition also a "cmd_output"
method that returns either an array or a string with the captured
command output (depending on the original function call context;
"command_noisy()" returns "undef") and $<cmdline> which returns the
command and its arguments (but without proper quoting).
Note that the "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 "close" the pipe; if you want to have that
automated, use "command_close_pipe()", which can throw the exception.
git_cmd_try { CODE } ERRMSG
This magical statement will automatically catch any
"Git::Error::Command" exceptions thrown by "CODE" and make your
program die with "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 "CODE"'s
return value.
Note that this is the only auto-exported function.
COPYRIGHT
Copyright 2006 by Petr Baudis <pasky AT suse.cz>.
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.
perl v5.16.3 2013-06-10 Git(3)
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