Section: User Contributed Perl Documentation (3pm)
"HTTP::Request"objects. These functions are usually more convenient to use than the standard
"HTTP::Request"constructor for the most common requests. The following functions are provided:
"HTTP::Request"object initialized with the ``GET'' method and the specified URL. It is roughly equivalent to the following call
HTTP::Request->new( GET => $url, HTTP::Headers->new(Header => Value,...), )but is less cluttered. What is different is that a header named
"Content"will initialize the content part of the request instead of setting a header field. Note that GET requests should normally not have a content, so this hack makes more sense for the PUT'() and POST'() functions described below. The get(...) method of
"LWP::UserAgent"exists as a shortcut for
:PUT $url, Header => Value,...
The content of the request can be specified using the ``Content pseudo-header. This steals a bit of the header field namespace as there is no way to directly specify a header that is actually called ``Content. If you really need this you must update the request returned in a separate statement.
:POST $url, Header => Value,...
:POST $url, $form_ref, Header => Value,...
:POST $url, Header => Value,..., Content => $form_ref
$form_ref. As for PUT'() the content can also be specified directly using the ``Content pseudo-header, and you may also provide the
$form_refargument can be used to pass key/value pairs for the form content. By default we will initialize a request using the
"application/x-www-form-urlencoded"content type. This means that you can emulate an HTML <form> POSTing like this:
This will create an HTTP::Request object that looks like this:
POST http://www.perl.org/survey.cgi Content-Length: 66 Content-Type: application/x-www-form-urlencoded
Multivalued form fields can be specified by either repeating the field name or by passing the value as an array reference.The POST method also supports the
"multipart/form-data"content used for Form-based File Upload as specified in RFC 1867. You trigger this content format by specifying a content type of
'form-data'as one of the request headers. If one of the values in the
$form_refis an array reference, then it is treated as a file part specification with the following interpretation:
[ $file, $filename, Header => Value... ] [ undef, $filename, Header => Value,..., Content => $content ]The first value in the array ($file) is the name of a file to open. This file will be read and its content placed in the request. The routine will croak if the file can't be opened. Use an
$filevalue if you want to specify the content directly with a
$filenameis the filename to report in the request. If this value is undefined, then the basename of the
$filewill be used. You can specify an empty string as
$filenameif you want to suppress sending the filename when you provide a
$filevalue. If a
$fileis provided by no
"Content-Encoding"will be filled in automatically with the values returned by LWP::MediaTypes::guess_media_type()
Sending my ~/.profile to the survey used as example above can be achieved by this:
This will create an HTTP::Request object that almost looks this (the boundary and the content of your ~/.profile is likely to be different):
POST http://www.perl.org/survey.cgi Content-Length: 388 Content-Type: multipart/form-data; boundary="6G+f"
--6G+f Content-Disposition: form-data; name="name"
Gisle Aas --6G+f Content-Disposition: form-data; name="email"
[email protected] --6G+f Content-Disposition: form-data; name="gender"
M --6G+f Content-Disposition: form-data; name="born"
1964 --6G+f Content-Disposition: form-data; name="init"; filename=".profile" Content-Type: text/plain
PATH=/local/perl/bin:$PATH export PATH
@]If you set the
$DYNAMIC_FILE_UPLOADvariable (exportable) to some TRUE value, then you get back a request object with a subroutine closure as the content attribute. This subroutine will read the content of any files on demand and return it in suitable chunks. This allow you to upload arbitrary big files without using lots of memory. You can even upload infinite files like /dev/audio if you wish; however, if the file is not a plain file, there will be no Content-Length header defined for the request. Not all servers (or server applications) like this. Also, if the file(s) change in size between the time the Content-Length is calculated and the time that the last chunk is delivered, the subroutine will
"Croak". The post(...) method of ``LWP::UserAgent'' exists as a shortcut for
Copyright 1997-2004, Gisle Aas
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
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