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LWP::Simple.3pm

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 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 LWP::UserAgent).

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/#.##'' 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, LWP::UserAgent, HTTP::Status, lwp-request, lwp-mirror