LWP::Simple − simple procedural interface to LWP
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 $content;
if (mirror("http://www.sn.no/", "foo") == RC_NOT_MODIFIED) {
...
}
if (is_success(getprint("http://www.sn.no/"))) {
...
}
This module is meant for people who want a simplified view of the libwww-perl library. It should also be suitable for one-liners. If you need more control or access to the header fields in the requests sent and responses received, then you should use the full object-oriented interface provided by the "LWP::UserAgent" module.
The following
functions are provided (and exported) by this module:
get($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 $ua−>env_proxy).
Note that if you are using both LWP::Simple and the very popular CGI .pm module, you may be importing a "head" function from each module, producing a warning like "Prototype mismatch: sub main::head ($) 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)".
LWP , lwpcook, LWP::UserAgent, HTTP::Status, lwp-request, lwp-mirror
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