NAME
HTTP::ProxyCheck - a class to check the functionality of HTTP proxy
servers.
SYNOPSIS
use HTTP::ProxyCheck;
my $proxy = 'proxy:8080';
my $url = 'http://search.cpan.org/';
my $proxy_check = new HTTP::ProxyCheck(
proxy => $proxy,
url => $url,
answer_size => 'header',
print_error => 0,
)
or die $HTTP::ProxyCheck::error;
print "Trying to connect to '$proxy' and retrieve '$url'\n";
if ( $proxy_check->check() ) {
print "'$proxy' returns:\n\n", $proxy_check->get_answer(), "\n\n";
}
else {
print "Error: ", $proxy_check->get_error(), "\n";
}
DESCRIPTION
HTTP::ProxyCheck is a class to check HTTP proxy servers. It connects to
given HTTP proxy servers and tries to retrieve a provided URL through
them.
CONSTRUCTOR
new( [attribute => $value, ...] )
"new()" is the HTTP::ProxyCheck object constructor.
If an error happens while constructing the object, use
$HTTP::ProxyCheck::error to get the error message.
All named attributes of "new()" are optional.
Attributes
* proxy => $proxy
Specifies the address of the proxy server to check. This can
also be done with "set_proxy()".
The proxy server address has to match the patter 'host:port'.
Host and port are tested whether they are valid. If you want
to disable this test, you can set "check_proxy => 0".
* check_proxy => 1|0
Set "check_proxy => 0" to disable the check whether the proxy
server address is valid.
The default value of "check_proxy" is 1 which means, the proxy
server address gets tested.
This attribute can also be set with "set_check_proxy()".
* url => $url
Specifies the URL to use for the proxy server check. This can
also be done with "set_url()".
The URL has to be of a valid form, e.g.
'http://search.cpan.org'. It gets tested whether it is valid.
If you want to disable this test, you can set "check_url =>
0".
* check_url => 1|0
Set "check_url => 0" to disable the check whether the URL is
valid.
The default value of "check_url" is 1 which means, the URL
gets tested.
This attribute can also be set with "set_check_url()".
* answer_size => short|header|full
Defines the size of the proxy server answer.
"short" means that only the HTTP status code, e.g.
HTTP/1.0 200 OK
is returned.
With "header" the full HTTP header gets returned, e.g.
HTTP/1.0 200 OK
Date: Tue, 12 Aug 2003 12:19:46 GMT
Server: Apache/1.3.27 (Unix) mod_perl/1.27
Cache-Control: max-age=3600
Expires: Tue, 12 Aug 2003 13:19:46 GMT
Last-Modified: Tue, 12 Aug 2003 12:19:46 GMT
Content-Type: text/html
X-Cache: MISS from search.cpan.org
X-Cache: MISS from hactar.earth.net
X-Cache-Lookup: HIT from hactar.earth.net:8080
Proxy-Connection: close
Use "full" if you want the HTTP header including the whole
data from the proxy server.
The default value of "answer_size" is "header".
This attribute can also be set with "set_answer_size()".
* user_agent => $user_agent
Specifies the name of the user agent sent to the proxy.
If you don't specify a user agent, "HTTP::ProxyCheck/1.3" is
used.
* verbose_errors => 0|1
Set "verbose_errors => 1" to enable verbose error messages.
Verbose error messages look like this:
$method failed: $error_message
And non-verbose error messages like this:
$error_message
The default value of "verbose_errors" is 0.
For more information see "ERROR HANDLING".
* print_error => 1|0
Set "print_error => 0" to disable that error messages are
displayed with "Carp::carp()".
The default value of "print_error" is 1.
For more information see "ERROR HANDLING".
* raise_error => 0|1
Set "raise_error => 1" to enable that error messages are
displayed with "Carp::croak()" and the program is brought to
an end.
The default value of "raise_error" is 0.
For more information see "ERROR HANDLING".
Return values
* Okay Blessed reference
* Error "undef"
The error message can be retrieved with
$HTTP::ProxyCheck::error.
METHODS
check( [attribute => $value, ...] )
"check()" does the actual proxy server checking. It connects to a
specified proxy server and tries to get a defined URL through it.
All named attributes of "check()" are optional, but "proxy" and "url"
must be either set as object or method attribute.
Attributes
* proxy => $proxy
Defines the proxy server to check.
"proxy => $proxy" has higher precedence than the object
attribute "proxy". It is only used by this method call. It
doesn't get saved as object attribute or changes the object
attribute. If you want to do this use "set_proxy()".
For more information see "CONSTRUCTOR".
* check_proxy => 1|0
Set "check_proxy => 0" to disable the check whether the proxy
server address is valid. If "check_proxy => 1" is set the
proxy server address gets tested.
This method attribute has higher precedence than the object
attribute "check_proxy". It is only used by this method call.
It doesn't get saved as object attribute or changes the object
attribute. If you want to do this use "set_check_proxy()".
* url => $url
Defines the URL to use with the proxy server check.
"url => $url" has higher precedence than the object attribute
"url". It is only used by this method call. It doesn't get
saved as object attribute or changes the object attribute. If
you want to do this use "set_url()".
For more information see "CONSTRUCTOR".
* check_url => 1|0
Set "check_url => 0" to disable the check whether the URL is
valid. If "check_url => 1" is set the URL gets tested.
This method attribute has higher precedence than the object
attribute "check_url". It is only used by this method call. It
doesn't get saved as object attribute or changes the object
attribute. If you want to do this use "set_check_url()".
* answer_size => short|header|full
Defines the size of the proxy server answer.
This method attribute has higher precedence than the object
attribute "answer_size". It is only used by this method call.
It doesn't get saved as object attribute or changes the object
attribute. If you want to do this use "set_answer_size()".
For more information see "CONSTRUCTOR".
Return values
* Okay 1
The answer of the proxy server can be retrieved with
"get_answer()" or $HTTP::ProxyCheck::answer
* Error "undef"
The error message can be retrieved with "get_error()" or
$HTTP::ProxyCheck::error
get_answer( )
"get_answer()" gets the most recent proxy server answer.
The proxy server answer is in the form specified by the "answer_size"
attribute of the HTTP::ProxyCheck object or the "check()" method.
For more information see "CONSTRUCTOR".
Return values
* Okay "$proxy_check->{answer}"
This is the most recent proxy server answer.
* Error "undef"
The error message can be retrieved with "get_error()" or
$HTTP::ProxyCheck::error
get_error( )
"get_error()" gets the most recent error message.
For more information see "ERROR HANDLING".
Return values
* Okay "$proxy_check->{error}"
This is the most recent error message.
get_proxy( )
"get_proxy()" gets the current value of the object attribute "proxy".
Return values
* Okay "$proxy_check->{proxy}"
This is the current proxy server address.
* Error "undef"
The error message can be retrieved with "get_error()" or
$HTTP::ProxyCheck::error
set_proxy( $proxy )
"set_proxy()" sets the value of the object attribute "proxy".
Attributes
* $proxy The proxy server address has to match the patter 'host:port'.
Host and port are tested whether they are valid. If you want
to disable this test, you can set the object attribute
"check_proxy => 0" or use set_check_proxy(0).
Return values
* Okay 1
* Error "undef"
The error message can be retrieved with "get_error()" or
$HTTP::ProxyCheck::error
get_check_proxy( )
"get_check_proxy()" gets the current value of the object attribute
"check_proxy".
Return values
* Okay "$proxy_check->{check_proxy}"
This is the current value of the "check_proxy" attribute.
set_check_proxy( $check )
"set_check_proxy" sets the object attribute "check_proxy".
Attributes
* $check Use 0 to disable the check whether the proxy server address is
valid and 1 to enable it.
Return values
* Okay 1
* Error "undef"
The error message can be retrieved with "get_error()" or
$HTTP::ProxyCheck::error
get_url( )
"get_url()" gets the current value of the object attribute "url".
Return values
* Okay "$proxy_check->{url}"
This is the current URL.
* Error "undef"
The error message can be retrieved with "get_error()" or
$HTTP::ProxyCheck::error
set_url( $url )
"set_url" sets the object attribute "url".
Attributes
* $url The URL has to be of a valid form, e.g.
'http://search.cpan.org'. It gets tested whether it is valid.
If you want to disable this test, you can set the object
attribute "check_url => 0" or use set_check_url(0).
Return values
* Okay 1
* Error "undef"
The error message can be retrieved with "get_error()" or
$HTTP::ProxyCheck::error
get_check_url( )
"get_check_url()" gets the current value of the object attribute
"check_url".
Return values
* Okay "$proxy_check->{check_url}"
This is the current value of the "check_url" attribute.
set_check_url( $check )
"set_check_url" sets the object attribute "check_url".
Attributes
* $check Use 0 to disable the check whether the URL is valid and 1 to
enable it.
Return values
* Okay 1
* Error "undef"
The error message can be retrieved with "get_error()" or
$HTTP::ProxyCheck::error
get_answer_size( )
"get_answer_size()" gets the current value of the object attribute
"answer_size".
Return values
* Okay "$proxy_check->{answer_size}"
This is the current answer size.
* Error "undef"
The error message can be retrieved with "get_error()" or
$HTTP::ProxyCheck::error
set_answer_size( $answer_size )
"set_answer_size" sets the object attribute "answer_size".
Attributes
* $answer_size
Defines the size of the proxy server answer. Use either
"short", "header" or "full" as value.
For more information see "CONSTRUCTOR".
Return values
* Okay 1
* Error "undef"
The error message can be retrieved with "get_error()" or
$HTTP::ProxyCheck::error
ERROR HANDLING
HTTP::ProxyCheck has a highly configurable error handling system. It is
configured with the attributes "verbose_errors", "print_error" and
"raise_error" at object creation:
my $proxy_check = new HTTP::ProxyCheck(
proxy => 'proxy:8080',
url => 'http://search.cpan.org',
verbose_errors => 1,
print_error => 0,
raise_error => 1,
);
Every time you call a method of HTTP::ProxyCheck and an error happens,
which means the method returns "undef", the error message can be
retrieved with "get_error()" or $HTTP::ProxyCheck::error:
$proxy_check->set_answer_size( 'full' )
or die $proxy_check->get_error();
$proxy_check->check()
or die $HTTP::ProxyCheck::error;
If there's an error during the object construction, you can't get the
error message through "get_error()". Use $HTTP::ProxyCheck::error
instead:
my $proxy_check = new HTTP::ProxyCheck( proxy => 'proxy' )
or die $HTTP::ProxyCheck::error;
The object attribute "verbose_errors" configures the verbosity of the
error message. Set "verbose_errors => 1" to enable verbose error
messages and "verbose_errors => 0" to disable verbose error messages.
Verbose error messages look like this:
$method failed: $error_message
And non-verbose error messages like this:
$error_message
The default value of "verbose_errors" is 0.
With "print_error" and "raise_error" you can set the degree of
automation of the error handling.
If "print_error" is set to 1, the error message is displayed with
"Carp::carp()". Set "print_error" to 0 to disable this feature.
If "raise_error" is set to 1, the error message is displayed with
"Carp::croak()" and the program is brought to an end. If "raise_error"
is set to 0, this feature is disabled.
The default value of "print_error" is 1 and of "raise_error" it is 0.
SUPPORT
Contact the "AUTHOR".
BUGS
Unknown
VERSION
HTTP::ProxyCheck version 1.2
CHANGES
1.3 Sun May 7 11:51:50 CEST 2006
- Charles Longeau <chl attuxfamily dot org> made a small patch to
specify the user agent, instead of a fixed "HTTP::ProxyCheck/$VERSION"
one.
1.2 Sat May 8 09:38:02 CEST 2004
- Fix to unset the error message of a previous IO::Socket::INET run
Thanks to Ben Schnopp <ben at schnopp dot com>
1.1 Tue Aug 12 19:45:00 CEST 2003
- rewrote the module
- added better error handling
- updated POD
1.0 Fri Feb 21 17:09:32 CET 2003
- gone stable after detailed testing
- updated POD (synopsis)
0.2 Fri Feb 21 11:57:43 CET 2003
- added check(answer => $type)
- renamed methods to gain more consistency
- updated POD (synopsis, methods)
0.1 Wed Feb 5 14:35:25 CET 2003
- original version
AUTHOR
Thomas Weibel
cpan@beeblebrox.net
http://beeblebrox.net/
COPYRIGHT
Copyright (c) 2004 - 2006 Thomas Weibel. All rights reserved.
This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.