• NAME
• SYNOPSIS
• DESCRIPTION
• CONSTRUCTOR
• new( [attribute => $value, ...] )
• METHODS
• check( [attribute => $value, ...] )
• get_answer( )
• get_error( )
• get_proxy( )
• set_proxy( $proxy )
• get_check_proxy( )
• set_check_proxy( $check )
• get_url( )
• set_url( $url )
• get_check_url( )
• set_check_url( $check )
• get_answer_size( )
• set_answer_size( $answer_size )
• ERROR HANDLING
• SUPPORT
• BUGS
• VERSION
• CHANGES
• AUTHOR
• COPYRIGHT

NAME

HTTP::ProxyCheck - a class to check the functionality of HTTP proxy servers.

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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";
    }

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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.

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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/1.4'' 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.

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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

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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.

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SUPPORT

Contact the AUTHOR.

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BUGS

Unknown

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VERSION

    HTTP::ProxyCheck version 1.2

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CHANGES

    1.4 Thu May 25 10:47:42 CEST 2006
        - Added installation instructions to README
    
    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

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AUTHOR

    Thomas Weibel
    cpan@beeblebrox.net
    http://beeblebrox.net/

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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.

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