| LWP::Simple(3pm) | User Contributed Perl Documentation | LWP::Simple(3pm) |
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 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").
The following functions are provided (and exported) by this module:
my $res = get($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).
my $res = head($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.
my $code = getprint($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.
my $code = getstore($url, $file)
Gets a document identified by a URL and stores it in the file. The return value is the HTTP response code.
my $code = mirror($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" in LWP::Simple, "getstore" in LWP::Simple or "mirror" in LWP::Simple. 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:
my $bool = is_success($rc);
True if response code indicated a successful request.
my $bool = is_error($rc)
True if response code indicated that an error occurred.
Note that if you are using both LWP::Simple and the very popular CGI 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
| 2019-05-14 | perl v5.28.1 |