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LWP::Simple
simple procedural interface to LWP

LWP::Simple - simple procedural interface to LWP


NAME

LWP::Simple - simple procedural interface to LWP


SYNOPSIS


 perl -MLWP::Simple -e 'getprint "http://www.sn.no";'

 use LWP::Simple;

 $content = get("http://www.sn.no/";);

 die "Couldn't get it!" unless defined $content;

 if (mirror("http://www.sn.no/";, "foo") == RC_NOT_MODIFIED) {

     ...

 }

 if (is_success(getprint("http://www.sn.no/";))) {

     ...

 }


DESCRIPTION

This module is meant for people who want a simplified view of the libwww-perl library. It should also be suitable for one-liners. If you need more control or access to the header fields in the requests sent and responses received, then you should use the full object-oriented interface provided by the LWP::UserAgent module.

The following functions are provided (and exported) by this module:

get($url)
The get() function will fetch the document identified by the given URL and return it. It returns undef if it fails. The $url argument can be either a simple string or a reference to a URI object.

You will not be able to examine the response code or response headers (like 'Content-Type') when you are accessing the web using this function. If you need that information you should use the full OO interface (see the LWP::UserAgent manpage).

head($url)
Get document headers. Returns the following 5 values if successful: ($content_type, $document_length, $modified_time, $expires, $server)

Returns an empty list if it fails. In scalar context returns TRUE if successful.

getprint($url)
Get and print a document identified by a URL. The document is printed to the selected default filehandle for output (normally STDOUT) as data is received from the network. If the request fails, then the status code and message are printed on STDERR. The return value is the HTTP response code.

getstore($url, $file)
Gets a document identified by a URL and stores it in the file. The return value is the HTTP response code.

mirror($url, $file)
Get and store a document identified by a URL, using If-modified-since, and checking the Content-Length. Returns the HTTP response code.

This module also exports the HTTP::Status constants and procedures. You can use them when you check the response code from getprint(), getstore() or mirror(). The constants are:


   RC_CONTINUE

   RC_SWITCHING_PROTOCOLS

   RC_OK

   RC_CREATED

   RC_ACCEPTED

   RC_NON_AUTHORITATIVE_INFORMATION

   RC_NO_CONTENT

   RC_RESET_CONTENT

   RC_PARTIAL_CONTENT

   RC_MULTIPLE_CHOICES

   RC_MOVED_PERMANENTLY

   RC_MOVED_TEMPORARILY

   RC_SEE_OTHER

   RC_NOT_MODIFIED

   RC_USE_PROXY

   RC_BAD_REQUEST

   RC_UNAUTHORIZED

   RC_PAYMENT_REQUIRED

   RC_FORBIDDEN

   RC_NOT_FOUND

   RC_METHOD_NOT_ALLOWED

   RC_NOT_ACCEPTABLE

   RC_PROXY_AUTHENTICATION_REQUIRED

   RC_REQUEST_TIMEOUT

   RC_CONFLICT

   RC_GONE

   RC_LENGTH_REQUIRED

   RC_PRECONDITION_FAILED

   RC_REQUEST_ENTITY_TOO_LARGE

   RC_REQUEST_URI_TOO_LARGE

   RC_UNSUPPORTED_MEDIA_TYPE

   RC_INTERNAL_SERVER_ERROR

   RC_NOT_IMPLEMENTED

   RC_BAD_GATEWAY

   RC_SERVICE_UNAVAILABLE

   RC_GATEWAY_TIMEOUT

   RC_HTTP_VERSION_NOT_SUPPORTED

The HTTP::Status classification functions are:

is_success($rc)
True if response code indicated a successful request.

is_error($rc)
True if response code indicated that an error occurred.

The module will also export the LWP::UserAgent object as $ua if you ask for it explicitly.

The user agent created by this module will identify itself as ``LWP::Simple/#.##'' (where ``#.##'' is the libwww-perl version number) and will initialize its proxy defaults from the environment (by calling $ua->env_proxy).


CAVEAT

Note that if you are using both LWP::Simple and the very popular CGI.pm module, you may be importing a head function from each module, producing a warning like ``Prototype mismatch: sub main::head ($) vs none''. Get around this problem by just not importing LWP::Simple's head function, like so:


        use LWP::Simple qw(!head);

        use CGI qw(:standard);  # then only CGI.pm defines a head()

Then if you do need LWP::Simple's head function, you can just call it as LWP::Simple::head($url).


SEE ALSO

LWP, lwpcook, the LWP::UserAgent manpage, the HTTP::Status manpage, lwp-request, lwp-mirror

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