Config::GitLike(3) User Contributed Perl Documentation Config::GitLike(3)NAMEConfig::GitLike - git-compatible config file parsing
SYNOPSIS
This module parses git-style config files, which look like this:
[core]
repositoryformatversion = 0
filemode = true
bare = false
logallrefupdates = true
[remote "origin"]
url = spang.cc:/srv/git/home.git
fetch = +refs/heads/*:refs/remotes/origin/*
[another-section "subsection"]
key = test
key = multiple values are OK
emptyvalue =
novalue
Code that uses this config module might look like:
use Config::GitLike;
# just load a specific file
my $data = Config::GitLike->load_file("~/.fooconf");
# or use the object interface to load /etc/config, ~/.config, and
# `pwd`/.config
my $c = Config::GitLike->new(confname => 'config');
$c->get( key => 'section.name' );
# make the return value a Perl true/false value
$c->get( key => 'core.filemode', as => 'bool' );
# replace the old value
$c->set(
key => 'section.name',
value => 'val1',
filename => '/home/user/.config',
);
# make this key have multiple values rather than replacing the
# old value
$c->set(
key => 'section.name',
value => 'val2',
filename => '/home/user/.config',
multiple => 1,
);
# replace all occurrences of the old value for section.name with a new one
$c->set(
key => 'section.name',
value => 'val3',
filename => '/home/user/.config',
multiple => 1,
replace_all => 1,
);
# make sure to reload the config files before reading if you've set
# any variables!
$c->load;
# get only the value of 'section.name' that matches '2'
$c->get( key => 'section.name', filter => '2' );
$c->get_all( key => 'section.name' );
# prefixing a search regexp with a ! negates it
$c->get_regexp( key => '!na' );
$c->rename_section(
from => 'section',
to => 'new-section',
filename => '/home/user/.config'
);
$c->remove_section(
section => 'section',
filename => '/home/user/.config'
);
# unsets all instances of the given key
$c->set( key => 'section.name', filename => '/home/user/.config' );
my %config_vals = $config->dump;
# string representation of config data
my $str = $config->dump;
# prints rather than returning
$config->dump;
DESCRIPTION
This module handles interaction with configuration files of the style
used by the version control system Git. It can both parse and modify
these files, as well as create entirely new ones.
You only need to know a few things about the configuration format in
order to use this module. First, a configuration file is made up of
key/value pairs. Every key must be contained in a section. Sections can
have subsections, but they don't have to. For the purposes of setting
and getting configuration variables, we join the section name,
subsection name, and variable name together with dots to get a key name
that looks like "section.subsection.variable". These are the strings
that you'll be passing in to "key" arguments.
Configuration files inherit from each other. By default,
"Config::GitLike" loads data from a system-wide configuration file, a
per-user configuration file, and a per-directory configuration file,
but by subclassing and overriding methods you can obtain any
combination of configuration files. By default, configuration files
that don't exist are just skipped.
See
http://www.kernel.org/pub/software/scm/git/docs/git-config.html#_configuration_file
<http://www.kernel.org/pub/software/scm/git/docs/git-
config.html#_configuration_file> for details on the syntax of git
configuration files. We won't waste pixels on the nitty gritty here.
While the behavior of a couple of this module's methods differ slightly
from the "git config" equivalents, this module can read any config file
written by git. The converse is usually true, but only if you don't
take advantage of this module's increased permissiveness when it comes
to key names. (See "DIFFERENCES FROM GIT-CONFIG" for details.)
This is an object-oriented module using Any::Moose. All subroutines are
object method calls.
A few methods have parameters that are always used for the same
purpose:
Filenames
All methods that change things in a configuration file require a
filename to write to, via the "filename" parameter. Since a
"Config::GitLike" object can be working with multiple config files that
inherit from each other, we don't try to figure out which one to write
to automatically and let you specify instead.
Casting
All get and set methods can make sure the values they're returning or
setting are valid values of a certain type: "bool", "int", "num", or
"bool-or-int" (or at least as close as Perl can get to having these
types). Do this by passing one of these types in via the "as"
parameter. The set method, if told to write bools, will always write
"true" or "false" (not anything else that "cast" considers a valid
bool).
Methods that are told to cast values will throw exceptions if the
values they're trying to cast aren't valid values of the given type.
See the "cast" method documentation for more on what is considered
valid for each type.
Filtering
All get and set methods can filter what values they return via their
"filter" parameter, which is expected to be a string that is a valid
regex. If you want to filter items OUT instead of IN, you can prefix
your regex with a ! and that will do the trick.
Now, on the the methods!
MAIN METHODS
There are the methods you're likely to use the most.
new( confname => 'config', encoding => 'UTF-8' )
Create a new configuration object with the base config name "confname".
If you are interested simply in loading one specific file, and not in
automatically loading a global file, a per-user file, and a per-
directory file, see "load_file", below.
"confname" is used to construct the filenames that will be loaded; by
default, these are "/etc/confname" (global configuration file),
"~/.confname" (user configuration file), and "<Cwd"/.confname>
(directory configuration file).
You can override these defaults by subclassing "Config::GitLike" and
overriding the methods "global_file", "user_file", and "dir_file". (See
"METHODS YOU MAY WISH TO OVERRIDE" for details.)
If you wish to enforce only being able to read/write config files that
git can read or write, pass in "compatible => 1" to this constructor.
The default rules for some components of the config file are more
permissive than git's (see "DIFFERENCES FROM GIT-CONFIG").
If you know that your Git config files are encoded with a known
character encoding, pass in "encoding => $encoding" to specify the name
of the encoding. Config::GitLike will then properly serialize and
deserialize the files with that encoding. Note that configutation
files written with "git config" are usually, but are not required to
be, in UTF-8.
confname
The configuration filename that you passed in when you created the
"Config::GitLike" object. You can change it if you want by passing in a
new name (and then reloading via "load").
load
This method is usually called implicitly on the first "get", "get_all",
"get_regex", or "dump" call used, and is only necessary if you want to
explicitly reload the data.
Load the global, local, and directory configuration file with the
filename "confname"(if they exist). Configuration variables loaded
later override those loaded earlier, so variables from the directory
configuration file have the highest precedence.
Pass in an optional path, and it will be passed on to "load_dirs"
(which loads the directory configuration file(s)).
Returns a hash copy of all loaded configuration data stored in the
module after the files have been loaded, or a hashref to this hash in
scalar context.
config_files
An array reference containing the absolute filenames of all config
files that are currently loaded, in the order they were loaded.
get
Parameters:
key => 'sect.subsect.key'
as => 'int'
human => 1
filter => '!foo'
Return the config value associated with "key" cast as an "as".
The "key" option is required (will return undef if unspecified); the
"as" amd "human" options are not (see cast for their meaning). Sections
and subsections are specified in the key by separating them from the
key name with a "." character. Sections, subsections, and keys may all
be quoted (double or single quotes).
If "key" doesn't exist in the config, or has no values which match the
filter, undef is returned. Dies with the exception "Multiple values" if
the given key has more than one value associated with it which match
the filter. (Use "get_all" to retrieve multiple values.)
Calls "load" if it hasn't been done already. Note that if you've run
any "set" calls to the loaded configuration files since the last time
they were loaded, you MUST call "load" again before getting, or the
returned configuration data may not match the configuration variables
on-disk.
get_all
Parameters:
key => 'section.sub'
as => 'int'
human => 1
filter => 'regex'
Like "get" but does not fail if the number of values for the key is not
exactly one.
Returns a list of values (or an arrayref in scalar context).
get_regexp
Parameters:
key => 'regex'
as => 'bool'
human => 1
filter => 'regex'
Similar to "get_all" but searches for values based on a key regex.
Returns a hash of name/value pairs (or a hashref in scalar context).
dump
In scalar context, return a string containing all configuration data,
sorted in ASCII order, in the form:
section.key=value
section2.key=value
If called in void context, this string is printed instead.
In list context, returns a hash containing all the configuration data.
set
Parameters:
key => 'section.name'
value => 'bar'
filename => File::Spec->catfile(qw/home user/, '.'.$config->confname)
filter => 'regex'
as => 'bool'
multiple => 1
replace_all => 1
Set the key "foo" in the configuration section "section" to the value
"bar" in the given filename.
Replace "key"'s value if "key" already exists.
To unset a key, pass in "key" but not "value".
Returns true on success.
If you need to have a . character in your variable name, you can
surround the name with quotes (single or double): "key =>
'section."foo.bar.com"'" Don't do this unless you really have to.
multiple values
By default, set will replace the old value rather than giving a key
multiple values. To override this, pass in "multiple => 1". If you want
to replace all instances of a multiple-valued key with a new value, you
need to pass in "replace_all => 1" as well.
group_set( $filename, $array_ref )
Same as "set", but set a group of variables at the same time without
writing to disk separately for each.
$array_ref contains a list of hash references which are essentially
hashes of arguments to "set", excluding the $filename argument since
that is specified separately and the same file is used for all
variables to be set at once.
rename_section
Parameters:
from => 'name.subname'
to => 'new.subname'
filename => '/file/to/edit'
Rename the section existing in "filename" given by "from" to the
section given by "to".
Throws an exception "No such section" if the section in "from" doesn't
exist in "filename".
If no value is given for "to", the section is removed instead of
renamed.
Returns true on success, false if "filename" didn't exist and thus the
rename did nothing.
remove_section
Parameters:
section => 'section.subsection'
filename => '/file/to/edit'
Just a convenience wrapper around "rename_section" for readability's
sake. Removes the given section (which you can do by renaming to
nothing as well).
add_comment
Parameters:
comment => "Begin editing here\n and then stop",
filename => '/file/to/edit'
indented => 1,
semicolon => 0,
Add a comment to the specified configuration file. The "comment" and
"filename" parameters are required. Comments will be added to the file
with "# " at the begnning of each line of the comment. Pass a true
value to "semicolon" if you'd rather they start with "; ". If your
comments are indented with leading white space, and you want that white
space to appear in front of the comment character, rather than after,
pass a true value to "indented".
cascade( $bool )
Gets or sets if only the deepest configuration file in a directory tree
is loaded, or if all of them are loaded, shallowest to deepest.
Alternately, "cascade => 1" can be passed to "new".
origins
Returns a hash mapping each config key with the file it was loaded
from.
METHODS YOU MAY WISH TO OVERRIDE
If your application's configuration layout is different from the
default, e.g. if its home directory config files are in a directory
within the home directory (like "~/.git/config") instead of just dot-
prefixed, override these methods to return the right directory names.
For fancier things like altering precedence, you'll need to override
"load" as well.
dir_file
Return a string containing the path to a configuration file with the
name "confname" in a directory. The directory isn't specified here.
global_file
Return the string "/etc/confname", the absolute name of the system-wide
configuration file with name "confname".
user_file
Return a string containing the path to a configuration file in the
current user's home directory with filename "confname".
load_dirs
Parameters:
'/path/to/look/in/'
Load the configuration file with the filename "dir_file" in the current
working directory into the memory or, if there is no config matching
"dir_file" in the current working directory, walk up the directory tree
until one is found. (No error is thrown if none is found.) If an
optional path is passed in, that directory will be used as the base
directory instead of the working directory.
You'll want to use "load_file" to load config files from your
overridden version of this subroutine.
Returns nothing of note.
OTHER METHODS
These are mostly used internally in other methods, but could be useful
anyway.
load_global
If a global configuration file with the absolute name given by
"global_file" exists, load its configuration variables into memory.
Returns the current contents of all the loaded configuration variables
after the file has been loaded, or undef if no global config file is
found.
load_user
If a configuration file with the absolute name given by "user_file"
exists, load its config variables into memory.
Returns the current contents of all the loaded configuration variables
after the file has been loaded, or undef if no user config file is
found.
load_file( $filename )
Takes a string containing the path to a file, opens it if it exists,
loads its config variables into memory, and returns the currently
loaded config variables (a hashref).
This method can also be called as a class method, which will die if the
file cannot be read. If called as an instance method, returns undef on
failure.
parse_content
Parameters:
content => 'str'
callback => sub {}
error => sub {}
Parses the given content and runs callbacks as it finds valid
information.
Returns undef on success and "error($content)" (the original content)
on failure.
"callback" is called like:
callback(section => $str, offset => $num, length => $num, name => $str, value => $str)
"name" and "value" may be omitted if the callback is not being called
on a key/value pair, or if it is being called on a key with no value.
"error" is called like:
error( content => $content, offset => $offset )
Where "offset" is the point in the content where the parse error
occurred.
If you need to use this method, you might be interested in
"error_callback" as well.
error_callback
Parameters:
content => 'str'
offset => 45
filename => '/foo/bar/.baz'
Made especially for passing to "parse_content", passed through the
"error" parameter like this:
error => sub {
error_callback( @_, filename => '/file/you/were/parsing' )
}
It's used internally wherever "parse_content" is used and will throw an
exception with a useful message detailing the line number, position on
the line, and contents of the bad line; if you find the need to use
"parse_content" elsewhere, you may find it useful as well.
set_multiple( $name )
Mark the key string $name as containing multiple values.
Returns nothing.
is_multiple( $name )
Return a true value if the key string $name contains multiple values;
false otherwise.
define
Parameters:
section => 'str'
name => 'str'
value => 'str'
Given a section, a key name, and a valueAX store this information in
memory in the config object.
Returns the value that was just defined on success, or undef if no name
and section were given and thus the key cannot be defined.
cast
Parameters:
value => 'foo'
as => 'int'
human => 1
Return "value" cast into the type specified by "as".
Valid values for "as" are "bool", "int", "num", or "bool-or-num". For
"bool", "true", "yes", "on", 1, and undef are translated into a true
value (for Perl); anything else is false. Specifying a true value for
the "human" argument will get you a human-readable 'true' or 'false'
rather than a value that plays along with Perl's definition of
truthiness (0 or 1).
For "int"s and "num"s, if "value" ends in "k", "m", or "g", it will be
multiplied by 1024, 1048576, and 1073741824, respectively, before being
returned. "int"s are truncated after being multiplied, if they have a
decimal portion.
"bool-or-int", as you might have guessed, gives you either a bool or an
int depending on which one applies.
If "as" is unspecified, "value" is returned unchanged.
format_section
Parameters:
section => 'section.subsection'
base => 1
Return a string containing the section/subsection header, formatted as
it should appear in a config file. If "bare" is true, the returned
value is not followed be a newline.
format_definition
Parameters:
key => 'str'
value => 'str'
bare => 1
Return a string containing the key/value pair as they should be printed
in the config file. If "bare" is true, the returned value is not tab-
indented nor followed by a newline.
DIFFERENCES FROM GIT-CONFIG
This module does the following things differently from git-config:
We are much more permissive about valid key names and section names.
For variables, instead of limiting variable names to alphanumeric
characters and -, we allow any characters except for = and newlines,
including spaces as long as they are not leading or trailing, and . as
long as the key name is quoted. For sections, any characters but
whitespace, [], and " are allowed. You can enforce reading/writing
only git-compatible variable names and section headers by passing
"compatible => 1" to the constructor.
When replacing variable values and renaming sections, we merely use a
substring replacement rather than writing out new lines formatted in
the default manner for new lines. Git's replacement/renaming (as of
1.6.3.2) is currently buggy and loses trailing comments and variables
that are defined on the same line as a section being renamed. Our
method preserves original formatting and surrounding information.
We also allow the 'num' type for casting, since in many cases we might
want to be more lenient on numbers.
We truncate decimal numbers that are cast to "int"s, whereas Git just
rejects them.
We don't support NUL-terminating output (the --null flag to git-
config). Who needs it?
BUGS
If you find any bugs in this module, report them at:
http://rt.cpan.org/
Include the version of the module you're using and any relevant
problematic configuration files or code snippets.
SEE ALSO
http://www.kernel.org/pub/software/scm/git/docs/git-config.html#_configuration_file
<http://www.kernel.org/pub/software/scm/git/docs/git-
config.html#_configuration_file>, Config::GitLike::Git,
<http://syncwith.us/> ("Config::GitLike" is used in Prophet/SD and
provides a working example)
LICENSE
This program is free software; you may modify and/or redistribute it
under the same terms as Perl itself.
COPYRIGHT
Copyright 2010 Best Practical Solutions, LLC
AUTHORS
Alex Vandiver <alexmv@bestpractical.com>, Christine Spang
<spang@bestpractical.com>
perl v5.14.2 2012-08-10 Config::GitLike(3)
