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Simple(3)	      User Contributed Perl Documentation	     Simple(3)

NAME
       Config::Simple -	simple configuration file class

SYNOPSIS
	 use Config::Simple;

	 # --- Simple usage. Loads the config. file into a hash:
	 Config::Simple->import_from('app.ini',	\%Config);

	 # --- OO interface:
	 $cfg =	new Config::Simple('app.ini');

	 # accessing values:
	 $user = $cfg->param('User');

	 # getting the values as a hash:
	 %Config = $cfg->vars();

	 # updating value with a string
	 $cfg->param('User', 'sherzodR');

	 # updating a value with an array:
	 $cfg->param('Users', ['sherzodR', 'geek', 'merlyn']);

	 # adding a new	block to an ini-file:
	 $cfg->param(-block=>'last-access', -values=>{'time'=>time()});

	 # accessing a block of	an ini-file;
	 $mysql	= $cfg->param(-block=>'mysql');

	 # saving the changes back to file:
	 $cfg->save();

	 # --- tie() interface
	 tie %Config, "Config::Simple",	'app.ini';

ABSTRACT
       Reading and writing configuration files is one of the most frequent
       tasks of	any software design. Config::Simple is the library that	helps
       you with	it.

       Config::Simple is a class representing configuration file object.  It
       supports	several	configuration file syntax and tries to identify	the
       file syntax automatically. Library supports parsing, updating and
       creating	configuration files.

ABOUT CONFIGURATION FILES
       Keeping configurable variables in your program source code is ugly,
       really.	And for	people without much of a programming experience,
       configuring your	programs is like performing black magic. Besides, if
       you need	to access these	values from within multiple files, want	your
       programs	to be able to update configuration files or want to provide a
       friendlier user interface for your configuration	files, you just	have
       to store	them in	an external file. That's where Config::Simple comes
       into play, making it very easy to read and write	configuration files.

       If you have never used configuration files before, here is a brief
       overview	of various syntax to choose from. Otherwise you	can jump to
       "PROGRAMMING STYLE".

   SIMPLE CONFIGURATION	FILE
       Simple syntax is	what you need for most of your projects. These are, as
       the name	asserts, the simplest. File consists of	key/value pairs,
       delimited by nothing but	white space. Keys (variables) should be
       strictly	alpha-numeric with possible dashes (-).	Values can hold	any
       arbitrary text. Here is an example of such a configuration file:

	 Alias	   /exec
	 TempFile  /usr/tmp

       Comments	start with a pound ('#') sign and cannot share the same	line
       with other configuration	data.

   HTTP-LIKE SYNTAX
       This format of separating key/value pairs is used by HTTP messages.
       Each key/value is separated by semi-colon (:). Keys are alphanumeric
       strings with possible '-'. Values can be	any arbitrary text:

       Example:

	 Alias:	/exec
	 TempFile: /usr/tmp

       It is OK	to have	spaces around ':'. Comments start with '#' and cannot
       share the same line with	other configuration data.

   INI-FILE
       These configuration files are more native to Win32 systems. Data	is
       organized in blocks. Each key/value pair	is delimited with an equal (=)
       sign. Blocks are	declared on their own lines enclosed in	'[' and	']':

	 [BLOCK1]
	 KEY1=VALUE1
	 KEY2=VALUE2

	 [BLOCK2]
	 KEY1=VALUE1
	 KEY2=VALUE2

       Your Winamp 2.x play list is an example of such a configuration file.

       This is the perfect choice if you need to organize your configuration
       file into categories:

	 [site]
	 url="http://www.handalak.com"
	 title="Web site of a \"Geek\""
	 author=sherzodr

	 [mysql]
	 dsn="dbi:mysql:db_name;host=handalak.com"
	 user=sherzodr
	 password=marley01

   SIMPLIFIED INI-FILE
       These files are pretty much similar to traditional ini-files, except
       they don't have any block declarations. This style is handy if you do
       not want	any categorization in your configuration file, but still want
       to use '=' delimited key/value pairs.  While working with such files,
       Config::Simple assigns them to a	default	block, called 'default'	by
       default :-).

	 url = "http://www.handalak.com"

       Comments	can begin with either pound ('#') or semi-colon	(';'). Each
       comment should reside on	its own	line

PROGRAMMING STYLE
       Most of the programs simply need	to be able to read settings from a
       configuration file and assign them to a hash. If	that's all you need,
       you can simply use its import_from() - class method with	the name of
       the configuration file and a reference to an existing (possibly empty)
       hash:

	 Config::Simple->import_from('myconf.cfg', \%Config);

       Now your	hash %Config holds all the configuration file's	key/value
       pairs.  Keys of a hash are variable names inside	your configuration
       file, and values	are their respective values. If	"myconf.cfg" was a
       traditional ini-file, keys of the hash consist of block name and
       variable	delimited with a dot, such as "block.var".

       If that's all you need, you can stop right here.	Otherwise, read	on.
       There is	much more Config::Simple offers.

   READING THE CONFIGURATION FILE
       To be able to use more features of the library, you will	need to	use
       its object interface:

	 $cfg =	new Config::Simple('app.cfg');

       The above line reads and	parses the configuration file accordingly.  It
       tries to	guess which syntax is used by passing the file to
       guess_syntax() method.  Alternatively, you can create an	empty object,
       and only	then read the configuration file in:

	 $cfg =	new Config::Simple();
	 $cfg->read('app.cfg');

       As in the first example,	read() also calls guess_syntax() method	on the
       file.

       If, for any reason, it fails to guess the syntax	correctly (which is
       less likely), you can try to debug by using its guess_syntax() method.
       It expects file handle for a  configuration file	and returns the	name
       of a syntax. Return value is one	of "ini", "simple" or "http".

	 open(FH, "app.cfg");
	 printf("This file uses	'%s' syntax\n",	$cfg->guess_syntax(\*FH));

   ACCESSING VALUES
       After you read the configuration	file in	successfully, you can use
       param() method to access	the configuration values. For example:

	 $user = $cfg->param("User");

       will return the value of	"User" from either simple configuration	file,
       or http-styled configuration as well as simplified ini-files. To	access
       the value from a	traditional ini-file, consider the following syntax:

	 $user = $cfg->param("mysql.user");

       The above returns the value of "user" from within "[mysql]" block.
       Notice the use of dot "." to delimit block and key names.

       Config::Simple also supports vars() method, which, depending on the
       context used, returns all the values either as hashref or hash:

	 my %Config = $cfg->vars();
	 print "Username: $Config{User}";

	 # If it was a traditional ini-file:
	 print "Username: $Config{'mysql.user'}";

       If you call vars() in scalar context, you will end up with a reference
       to a hash:

	 my $Config = $cfg->vars();
	 print "Username: $Config->{User}";

       If you know what	you're doing, you can also have	an option of importing
       all the names from the configuration file into your current name	space
       as global variables.  All the block/key names will be uppercased	and
       will be converted to Perl's valid variable names; that is, all the dots
       (block-key separator) and other '\W' characters will be substituted
       with underscore '_':

	 $cfg =	new Config::Simple('app.cfg');
	 $cfg->import_names();

	 # or, with a single line:
	 Config::Simple->new('app.cfg')->import_names();

	 print STDERR "Debugging mode is on" if	$DEBUG_MODE;

       In the above example, if	there was a variable 'mode' under '[debug]'
       block, it will be now accessible	via $DEBUG_MODE, as opposed to
       $cfg->param('debug.mode');

       "import_names()"	by default imports the values to its caller's name
       space.  Optionally, you can specify where to import the values by
       passing the name	of the name space as the first argument. It also
       prevents	potential name collisions:

	 Config::Simple->new('app.cfg')->import_names('CFG');
	 print STDERR "Debugging mode is on" if	$CFG::DEBUG_MODE;

       If all you want is to import values from	a configuration	file, the
       above syntax may	still seem longer than necessary. That's why
       Config::Simple supports import_from() - class method, which is called
       with the	name of	the configuration file.	It will	call import_names()
       for you:

	 Config::Simple->import_from('app.cfg');

       The above line imports all the variables	into the caller's name space.
       It's similar to calling import_names() on an object. If you pass	a
       string as the second argument, it will treat it as the alternative name
       space to	import the names into. As we already showed in the very	first
       example,	you can	also pass a reference to an existing hash as the
       second argument.	In this	case, that hash	will be	modified with the
       values of the configuration file.

	 # import into $CFG name space:
	 Config::Simple->import_from('app.cfg',	'CFG');

	 # import into %Config hash:
	 Config::Simple->import_from('app.cfg',	\%Config);

       The above line imports all the values to	'CFG' name space.
       import_from() returns underlying	Config::Simple object (which you may
       not even	need anymore):

	 $cfg =	Config::Simple->import_from('app.cfg', \my %Config);
	 $cfg->write('app.cfg.bak');

   UPDATING THE	VALUES
       Configuration values, once read into Config::Simple, can	be updated
       from within your	program	by using the same param() method used for
       accessing them. For example:

	 $cfg->param("User", "sherzodR");

       The above line changes the value	of "User" to "sherzodR". Similar
       syntax is applicable for	ini-files as well:

	 $cfg->param("mysql.user", "sherzodR");

       If the key you're trying	to update does not exist, it will be created.
       For example, to add a new "[session]" block to your ini-file, assuming
       this block doesn't already exist:

	 $cfg->param("session.life", "+1M");

       You can also delete values calling delete() method with the name	of the
       variable:

	 $cfg->delete('mysql.user'); # deletes 'user' under [mysql] block

   SAVING/WRITING CONFIGURATION	FILES
       The above updates to the	configuration values are in-memory operations.
       They do not reflect in the file itself. To modify the files
       accordingly, you	need to	call either "write()" or "save()" methods on
       the object:

	 $cfg->write();

       The above line writes the modifications to the configuration file.
       Alternatively, you can pass a name to either write() or save() to
       indicate	the name of the	file to	create instead of modifying existing
       configuration file:

	 $cfg->write("app.cfg.bak");

       If you want the changes saved at	all times, you can turn	"autosave"
       mode on by passing true value to	$cfg->autosave(). It will make sure
       before your program is terminated, all the configuration	values are
       written back to its file:

	 $cfg =	new Config::Simple('aff.cfg');
	 $cfg->autosave(1);

   CREATING CONFIGURATION FILES
       Occasionally, your programs may want to create their own	configuration
       files on	the fly, possibly from a user input. To	create a configuration
       file from scratch using Config::Simple, simply create an	empty
       configuration file object and define your syntax. You can do it by
       either passing "syntax" option to new(),	or by calling syntax() method.
       Then play with param() method as	you normally would.  When you're done,
       call write() method with	the name of the	configuration file:

	 $cfg =	new Config::Simple(syntax=>'ini');
	 # or you could	also do:
	 # $cfg->autosave('ini')

	 $cfg->param("mysql.dsn", "DBI:mysql:db;host=handalak.com");
	 $cfg->param("mysql.user", "sherzodr");
	 $cfg->param("mysql.pass", 'marley01');
	 $cfg->param("site.title", 'sherzodR "The Geek"');
	 $cfg->write("new.cfg");

       This creates a file "new.cfg" with the following	content:

	 ; Config::Simple 4.43
	 ; Sat Mar  8 00:32:49 2003

	 [site]
	 title=sherzodR	"The Geek"

	 [mysql]
	 pass=marley01
	 dsn=DBI:mysql:db;host=handalak.com
	 user=sherzodr

       Neat, huh? Supported syntax keywords are	"ini", "simple"	or "http".
       Currently there is no support for creating simplified ini-files.

   MULTIPLE VALUES
       Ever wanted to define array of values in	your single configuration
       variable? I have!  That's why Config::Simple supports this fancy
       feature as well.	Simply separate	your values with a comma:

	 Files hp.cgi, template.html, styles.css

       Now param() method returns an array of values:

	 @files	= $cfg->param("Files");
	 unlink	$_ for @files;

       If you want a comma as part of a	value, enclose the value(s) in double
       quotes:

	 CVSFiles "hp.cgi,v", "template.html,v", "styles.css,v"

       In case you want	either of the values to	hold literal quote ("),	you
       can escape it with a backlash:

	 SiteTitle "sherzod \"The Geek\""

   TIE INTERFACE
       If OO style intimidates you, and	"import_from()"	is too simple for you,
       Config::Simple also supports tie() interface. This interface allows you
       to tie()	an ordinary Perl hash to the configuration file. From that
       point on, you can use the variable as an	ordinary Perl hash.

	 tie %Config, "Config::Simple",	'app.cfg';

	 # Using %Config as an ordinary	hash
	 print "Username is '$Config{User}'\n";
	 $Config{User} = 'sherzodR';

       The difference between "import_from($file, \%Hash)" is, all the changes
       you make	to the hash after tie()ing it, will also reflect in the
       configuration file object.  If autosave() was turned on,	they will also
       be written back to file:

	 tie %Config, "Config::Simple",	"app.cfg";
	 tied(%Config)->autosave(1);

       To access the method provided in	OO syntax, you need to get underlying
       Config::Simple object. You can do so with tied()	function:

	 tied(%Config)->write();

       WARNING:	tie interface is experimental and not well tested yet. Let me
       know if you encounter a problem.

MISCELLANEOUS
   CASE	SENSITIVITY
       By default, configuration file keys and values are case sensitive.
       Which means, $cfg->param("User")	and $cfg->param("user")	are referring
       to two different	values.	 But it	is possible to force Config::Simple to
       ignore cases all	together by enabling "-lc" switch while	loading	the
       library:

	 use Config::Simple ('-lc');

       WARNING:	If you call write() or save(), while working on	"-lc" mode,
       all the case information	of the original	file will be lost. So use it
       if you know what	you're doing.

   USING QUOTES
       Some people suggest if values consist of	none alpha-numeric strings,
       they should be enclosed in double quotes. Well, says them! Although
       Config::Simple supports parsing such configuration files	already, it
       doesn't follow this rule	while writing them.  If	you really need	it to
       generate	such compatible	configuration files, "-strict" switch is what
       you need:

	 use Config::Simple '-strict';

       Now, when you write the configuration data back to files, if values
       hold any	none alpha-numeric strings, they will be quoted	accordingly.
       All the double quotes that are part of the value	will be	escaped	with a
       backslash.

   EXCEPTION HANDLING
       Config::Simple doesn't believe in dying that easily (unless you insult
       it using	wrong syntax).	It leaves the decision to the programmer
       implementing the	library. You can use its error() - class method	to
       access underlying error message.	Methods	that require you to check for
       their return values are read() and write(). If you pass filename	to
       new(), you will need to check its return	value as well. They return any
       true value indicating success, undef otherwise:

	 # following new() always returns true:
	 $cfg =	new Config::Simple();

	 # read() can fail:
	 $cfg->read('app.cfg') or die $cfg->error();

	 # following new() can fail:
	 $cfg =	new Config::Simple('app.cfg') or die Config::Simple->error();

	 # import_from() calls read(), so it can fail:
	 Config::Simple->import_from('app.cfg',	\%Config) or die Config::Simple->error();

	 # write() may fail:
	 $cfg->write() or die $cfg->error();

	 # tie() may fail, since it calls new()	with a filename
	 tie %Config, "Config::Simple",	'app.cfg' or die Config::Simple->error();

METHODS
       new()
	   - constructor. Optionally accepts several arguments.	Returns
	   Config::Simple object.  Supported arguments are filename, syntax,
	   autosave. If	there is a single argument, will be treated as the
	   name	of the configuration file.

       autosave([$bool])
	   - turns 'autosave' mode on if passed	true argument. Returns current
	   autosave mode if used without arguments. In 'autosave' mode
	   Config::Simple writes all the changes back to its file without you
	   having to call write() or save()

       read()
	   - accepts name  of the configuration	file to	parse. Before that, it
	   tries to guess the syntax of	the file by calling guess_syntax()
	   method. Then	calls either of	parse_ini_file(), parse_cfg_file() or
	   parse_http_file() accordingly. If the name of the file is provided
	   to the constructor -	new(), there is	no need	to call	read().

       param([$name], [$value])
	   - used for accessing	and updating configuration variables. If used
	   with	no arguments returns all the available names from the
	   configuration file.

       delete($name)
	   - deletes a variable	from a configuration file. $name has the same
	   meaning and syntax as it does in param($name)

       clear()
	   - clears all	the data from the object. Calling save() or turning
	   autosave() on results in an empty configuration file	as well.

       vars()
	   - depending on the context used, returns all	the values available
	   in the configuration	file either as a hash or a reference to	a hash

       import_names([$NS])
	   - imports all the names from	the configuration file to the caller's
	   name	space. Optional	argument, if passed, will be treated as	the
	   name	space variables	to be imported into.  All the names will be
	   uppercased. Non-alphanumeric	strings	in the values will be
	   underscored

       import_from($file, \%hash | $NS)
	   - class method. If the second argument is a reference to an
	   existing hash, it will load all the configuration contents into
	   that	hash. If the second argument is	a string, it will be treated
	   as the name space variables should be imported into,	just like
	   import_names() does.

       get_block($name)
	   is mostly used for accessing	blocks in ini-styled configuration
	   files.  Returns a hashref of	all the	key/value pairs	of a given
	   block. Also supported by param() method with	the help of "-block"
	   option:

	     $hash = $cfg->get_block('Project');
	     # is the same as saying:
	     $hash = $cfg->param(-block=>'Project');

       set_block($name,	$values)
	   used	in assigning contents to a block in ini-styled configuration
	   files. $name	should be the name of a	[block], and $values is
	   assumed to be a hashref mapping key/value pairs.  Also supported by
	   param() method with the help	of "-block" and	"-value" (or
	   "-values") options:

	     $cfg->set_block('Project',	{Count=>3, 'Multiple Column' =>	20});
	     # is the same as:
	     $cfg->param(-block=>'Project', -value=>{Count=>3, 'Multiple Column' => 20});

	   Warning: all	the contents of	a block, if previously existed will be
	   wiped out.  If you want to set specific key/value pairs, use
	   explicit method:

	     $cfg->param('Project.Count', 3);

       as_string()
	   - returns the configuration file as a chunk of text.	It is the same
	   text	used by	write()	and save() to store the	new configuration file
	   back	to file.

       write()
	   - writes the	configuration file into	disk. Argument,	if passed,
	   will	be treated as the name of the file configuration variables
	   should be saved in.

       save()
	   - same as write().

       dump()
	   - for debugging only. Dumps the whole Config::Simple	object using
	   Data::Dumper.  Argument, if passed, will be treated as the name of
	   the file object should be dumped in.	 The second argument specifies
	   amount of indentation as documented in Data::Dumper manual. Default
	   indent size is 2.

       error()
	   - returns the last error message from read/write or import_*
	   operations.

TODO
       o   Support for lines with continuation character, '\'. Currently its
	   support is restricted and quite possibly buggy.

       o   Retaining comments while writing the	configuration files back
	   and/or methods for manipulating comments. Everyone loves comments!

       o   Retain the order of the blocks and other variables in the
	   configuration files.

BUGS
       Submit bugs and possibly	patches	to Sherzod B. Ruzmetov
       <sherzodr@cpan.org>.

CREDITS
       Michael Caldwell	(mjc@mjcnet.com)
	   whitespace support, "-lc" switch and	for various bug	fixes

       Scott Weinstein (Scott.Weinstein@lazard.com)
	   bug fix in TIEHASH

       Ruslan U. Zakirov <cubic@wr.miee.ru>
	   default name	space suggestion and patch

       Hirosi Taguti
	   import_names() and import_from() idea.

       Vitaly Kushneriuk
	   for bug fixes and suggestions

COPYRIGHT
	 Copyright (C) 2002-2003 Sherzod B. Ruzmetov.

	 This software is free library.	You can	modify and/or distribute it
	 under the same	terms as Perl itself

AUTHOR
	 Sherzod B. Ruzmetov E<lt>sherzodr@cpan.orgE<gt>
	 URI: http://author.handalak.com

SEE ALSO
       Config::General,	Config::Simple,	Config::Tiny

perl v5.32.0			  2006-09-12			     Simple(3)

NAME | SYNOPSIS | ABSTRACT | ABOUT CONFIGURATION FILES | PROGRAMMING STYLE | MISCELLANEOUS | METHODS | TODO | BUGS | CREDITS | COPYRIGHT | AUTHOR | SEE ALSO

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