/ 
HTTP-Browscap-0.02
River stage zero No dependents
/ HTTP::Browscap

NAME

HTTP::Browscap - Parse and search browscap.ini files

SYNOPSIS

use HTTP::Browscap;

my $capable = browscap();

if( $capable->{wap} ) {
    output_WAP();
}

if( $capable->{css} > 1 ) {
    # Browser can handle CSS2
}

# OO interface
my $BC = HTTP::Browscap->new( 'browscap.ini' );

$capable = $BC->match( $ENV{HTTP_USER_AGENT} );

ABSTRACT

Browscap.ini is a file, introduced with Microsoft's IIS, that lists the User-Agent strings that different browsers send, and various capabilities of those browsers. This module parses browscap.ini and allows you to find the capability definitions for a given browser.

DESCRIPTION

Starting with Microsoft's IIS, a browscap.ini file was used to list the capabilities of various browsers. Using the User-Agent string that a browser sends in the HTTP request, the capabilities of a browser are retrieved. If an exact match of the User-Agent string isn't found, wild-card expantion is done. If all fails, a default browser definition is used.

There are limits the usefulness of browscap.ini. It only detects if a browser has a certain capability, but not if this capability has been deactivated or if it's a buggy implementation. In particular, most CSS and JavaScript implementations will make you scream.

Capabilities

The browser capability definition returned by browscap() or match() is a hash reference. The keys are defined below. Boolean capabilites can have values '' (false) or 1 (true).

Microsoft defines the following capabilities :

activexcontrols

Browser supports ActiveX controls? Boolean.

backgroundsounds

Browser supports background sounds? Boolean.

beta

Is this a beta version of the browser? Boolean.

browser

String containing a useful name for the browser.

cdf

Does the browser support Channel Definition Format for Webcasting? Boolean.

cookies

Does the browser support cookies? Note that this does not mean that the browser has cookie support currently turned on. Boolean.

frames

Does the browser support HTML <FRAMESET> and <FRAME> tags? Boolean.

javaapplets

Does the browser support Java applets? Note that even if this is true, the user could have Java turned off. Boolean.

javascript

Does the browser support javascript? Note that even if this is true, the user could have javascript turned off. Boolean.

platform

Which platform (ie, OS) is the browser running on. Example : WinNT, WinXP, Win2003, Palm, Linux, Debian.

If you want a list of all possible values, run the following on your browscap.ini file :

grep platform= browscap.ini | sort | uniq
tables

Does the browser support HTML <TABLE> tags? Boolean.

vbscript

Does the browser support VBscript? Note that even if this is true, the user should have VBscript turned off. Boolean.

version

Full version number of the browser. Example: 1.10

Gary Keith adds the following:

aol

Is this an AOL-branded browser? Boolean.

crawler

Is this browser in fact a web-crawler or spider, often sent by a search engine? Boolean.

css

CSS version supported by this browser. Possible values : 0 (no CSS support), 1 or 2.

iframes

Does the browser support MS's <IFRAME> tags? Boolean.

netclr

Is this a .NET CLR user-agent? Boolean.

majorver

Major version number. Example: given a version of 1.10, majorver is 1.

minorver

Minor version number. Example: given a version of 1.10, minorver is 10.

stripper

Identifies the browser as a crawler that does not obey robots.txt. This includes e-mail harvesters, download managers and so on. Boolean.

wap

Is browser a WAP-enabled mobile phone? Boolean.

win16

Is this the 16-bit windows version of the browser? Detecting this might be useful if you want the user to save a file. Boolean.

HTTP::Browscap adds the following:

UA

Full text of the User-Agent string used to match this definition.

LINE

Line in browscap.ini where the browser's capabilites are defined. Useful for debuging.

The browscap.ini standard also defines parent, which is a link to another capability list that complements the current definition. HTTP::Browscap handles these internaly, so that you only have to do one lookup.

Note that, contrary to other implementations, all capability names are in lower case, except for UA and LINE. This means you should look for win16 instead of Win16.

Cached data

Because parsing browscap.ini is slow, a cached version of the parsed data is automatically created and used where possible. Normaly this cached version is created when you ran browscap-update during installation.

The cache file is a MLDBM file created with DB_File and Storable. You may change this by overloading __save_cache and __open_cache.

UPDATING browscap.ini

You will want to periodically fetch a new browscap.ini. This can be done with the following :

wget -O browscap.ini \
    "http://www.garykeith.com/browsers/stream.asp?BrowsCapINI"
browscap-update browscap.ini
rm browscap.ini

However, you must read http://www.garykeith.com/browsers/terms.asp before automating this.

FUNCTIONS

browscap

$def = browscap();
$def = browscap( $ua );

Find the capabilities of a browser identified by a given User-Agent string. If the string is missing, browscap will attempt to find one. See __guess_ua below.

Returns a hashref. See Capabilities above.

METHODS

There is also an object oriented interface to this module.

new

my $BC = HTTP::Browscap->new;
my $BC = HTTP::Browscap->new( $ini_file );

Creates a new browscap object. If you do not specify $ini_file, the system's browscap.ini will be used.

match

$def = $BC->match;
$def = $BC->match( $ua );

Find the capabilities of a browser identified by the User-Agent string given in $ua. If the string is missing, browscap will attempt to find one. See __guess_ua below.

Returns a hashref. See Capabilities above.

open

$BC->open

Parse and load the browscap.ini file. If there is a cache-file present and it is more recent then browscap.ini, the cache-file is used instead. Creates the cache file if possible

This method is called automatically when needed. You should only call this yourself when you want to create a cache file but not bother with matching.

OVERLOADING METHODS

The following methods are documented in case you wish to create a sub-class.

__guess_ua

$BC->__guess_ua;

Used to guess at a User-Agent string. First __guess_ua looks in $ENV{HTTP_USER_AGENT} (CGI environement variable). If this fails and $ENV{MOD_PERL} is set, browscap will use the mod_perl's headers_in() to find it. If both these fails, the default User-Agent is returned, which is probably not what you want.

Returns the User-Agent string.

__set_file

$BC->__set_file( $file );

Called to set a new browscap.ini file. This method set's data members, generates the new cache-file name based on $file and clears any parsed data from memory.

__save_cache

Saves the parsed browscap.ini file (which is in {data}) to the cache file named {cache}.

Returns true on success.

Returns false on failure, with $! set accordingly.

__open_cache

Called to open the cache {cache} and tie it to {data}.

Returns true on success. Dies on failure.

__parse

Load and parse the browscap.ini file. You will have to read the source code if you want to modify it.

__parse_wild

Converts a UA string from browscap.ini to a Perl patern. The UA strings in browscap.ini may contain * or ., which act like file-globs.

SEE ALSO

http://www.garykeith.com/browsers, http://www.microsoft.com/windows2000/en/server/iis/default.asp?url=/windows2000/en/server/iis/htm/asp/comp1g11.htm HTTP::BrowserDetect.

AUTHOR

Philip Gwyn, <gwyn-AT-cpan.org>

COPYRIGHT AND LICENSE

Copyright 2005-2006 by Philip Gwyn

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.