1LWP::UserAgent(3) User Contributed Perl Documentation LWP::UserAgent(3)
2
6 LWP::UserAgent - Web user agent class
7
9 use strict;
10 use warnings;
11 use LWP::UserAgent ();
13 my $ua = LWP::UserAgent->new(timeout => 10);
15 $ua->env_proxy;
16 my $response = $ua->get('http://example.com');
18 if ($response->is_success) {
20 print $response->decoded_content;
21 }
22 else {
23 die $response->status_line;
24 }
25 Extra layers of security (note the "cookie_jar" and
27 "protocols_allowed"):
28 use strict;
30 use warnings;
31 use HTTP::CookieJar::LWP ();
33 use LWP::UserAgent ();
34 my $jar = HTTP::CookieJar::LWP->new;
36 my $ua = LWP::UserAgent->new(
37 cookie_jar => $jar,
38 protocols_allowed => ['http', 'https'],
39 timeout => 10,
40 );
41 $ua->env_proxy;
43 my $response = $ua->get('http://example.com');
45 if ($response->is_success) {
47 print $response->decoded_content;
48 }
49 else {
50 die $response->status_line;
51 }
52
54 The LWP::UserAgent is a class implementing a web user agent.
55 LWP::UserAgent objects can be used to dispatch web requests.
56 In normal use the application creates an LWP::UserAgent object, and
58 then configures it with values for timeouts, proxies, name, etc. It
59 then creates an instance of HTTP::Request for the request that needs to
60 be performed. This request is then passed to one of the request method
61 the UserAgent, which dispatches it using the relevant protocol, and
62 returns a HTTP::Response object. There are convenience methods for
63 sending the most common request types: "get" in LWP::UserAgent, "head"
64 in LWP::UserAgent, "post" in LWP::UserAgent, "put" in LWP::UserAgent
65 and "delete" in LWP::UserAgent. When using these methods, the creation
66 of the request object is hidden as shown in the synopsis above.
67 The basic approach of the library is to use HTTP-style communication
69 for all protocol schemes. This means that you will construct
70 HTTP::Request objects and receive HTTP::Response objects even for non-
71 HTTP resources like gopher and ftp. In order to achieve even more
72 similarity to HTTP-style communications, gopher menus and file
73 directories are converted to HTML documents.
74
76 The following constructor methods are available:
77 clone
79 my $ua2 = $ua->clone;
80 Returns a copy of the LWP::UserAgent object.
82 CAVEAT: Please be aware that the clone method does not copy or clone
84 your "cookie_jar" attribute. Due to the limited restrictions on what
85 can be used for your cookie jar, there is no way to clone the
86 attribute. The "cookie_jar" attribute will be "undef" in the new object
87 instance.
88 new
90 my $ua = LWP::UserAgent->new( %options )
91 This method constructs a new LWP::UserAgent object and returns it.
93 Key/value pair arguments may be provided to set up the initial state.
94 The following options correspond to attribute methods described below:
95 KEY DEFAULT
97 ----------- --------------------
98 agent "libwww-perl/#.###"
99 from undef
100 conn_cache undef
101 cookie_jar undef
102 default_headers HTTP::Headers->new
103 local_address undef
104 ssl_opts { verify_hostname => 1 }
105 max_size undef
106 max_redirect 7
107 parse_head 1
108 protocols_allowed undef
109 protocols_forbidden undef
110 requests_redirectable ['GET', 'HEAD']
111 timeout 180
112 proxy undef
113 no_proxy []
114 The following additional options are also accepted: If the "env_proxy"
116 option is passed in with a true value, then proxy settings are read
117 from environment variables (see "env_proxy" in LWP::UserAgent). If
118 "env_proxy" isn't provided, the "PERL_LWP_ENV_PROXY" environment
119 variable controls if "env_proxy" in LWP::UserAgent is called during
120 initialization. If the "keep_alive" option value is defined and non-
121 zero, then an "LWP::ConnCache" is set up (see "conn_cache" in
122 LWP::UserAgent). The "keep_alive" value is passed on as the
123 "total_capacity" for the connection cache.
124 "proxy" must be set as an arrayref of key/value pairs. "no_proxy" takes
126 an arrayref of domains.
127
129 The settings of the configuration attributes modify the behaviour of
130 the LWP::UserAgent when it dispatches requests. Most of these can also
131 be initialized by options passed to the constructor method.
132 The following attribute methods are provided. The attribute value is
134 left unchanged if no argument is given. The return value from each
135 method is the old attribute value.
136 agent
138 my $agent = $ua->agent;
139 $ua->agent('Checkbot/0.4 '); # append the default to the end
140 $ua->agent('Mozilla/5.0');
141 $ua->agent(""); # don't identify
142 Get/set the product token that is used to identify the user agent on
144 the network. The agent value is sent as the "User-Agent" header in the
145 requests.
146 The default is a string of the form "libwww-perl/#.###", where "#.###"
148 is substituted with the version number of this library.
149 If the provided string ends with space, the default "libwww-perl/#.###"
151 string is appended to it.
152 The user agent string should be one or more simple product identifiers
154 with an optional version number separated by the "/" character.
155 conn_cache
157 my $cache_obj = $ua->conn_cache;
158 $ua->conn_cache( $cache_obj );
159 Get/set the LWP::ConnCache object to use. See LWP::ConnCache for
161 details.
162 cookie_jar
164 my $jar = $ua->cookie_jar;
165 $ua->cookie_jar( $cookie_jar_obj );
166 Get/set the cookie jar object to use. The only requirement is that the
168 cookie jar object must implement the "extract_cookies($response)" and
169 "add_cookie_header($request)" methods. These methods will then be
170 invoked by the user agent as requests are sent and responses are
171 received. Normally this will be a HTTP::Cookies object or some
172 subclass. You are, however, encouraged to use HTTP::CookieJar::LWP
173 instead. See "BEST PRACTICES" for more information.
174 use HTTP::CookieJar::LWP ();
176 my $jar = HTTP::CookieJar::LWP->new;
178 my $ua = LWP::UserAgent->new( cookie_jar => $jar );
179 # or after object creation
181 $ua->cookie_jar( $cookie_jar );
182 The default is to have no cookie jar, i.e. never automatically add
184 "Cookie" headers to the requests.
185 Shortcut: If a reference to a plain hash is passed in, it is replaced
187 with an instance of HTTP::Cookies that is initialized based on the
188 hash. This form also automatically loads the HTTP::Cookies module. It
189 means that:
190 $ua->cookie_jar({ file => "$ENV{HOME}/.cookies.txt" });
192 is really just a shortcut for:
194 require HTTP::Cookies;
196 $ua->cookie_jar(HTTP::Cookies->new(file => "$ENV{HOME}/.cookies.txt"));
197 credentials
199 my $creds = $ua->credentials();
200 $ua->credentials( $netloc, $realm );
201 $ua->credentials( $netloc, $realm, $uname, $pass );
202 $ua->credentials("www.example.com:80", "Some Realm", "foo", "secret");
203 Get/set the user name and password to be used for a realm.
205 The $netloc is a string of the form "<host>:<port>". The username and
207 password will only be passed to this server.
208 default_header
210 $ua->default_header( $field );
211 $ua->default_header( $field => $value );
212 $ua->default_header('Accept-Encoding' => scalar HTTP::Message::decodable());
213 $ua->default_header('Accept-Language' => "no, en");
214 This is just a shortcut for "$ua->default_headers->header( $field =>
216 $value )".
217 default_headers
219 my $headers = $ua->default_headers;
220 $ua->default_headers( $headers_obj );
221 Get/set the headers object that will provide default header values for
223 any requests sent. By default this will be an empty HTTP::Headers
224 object.
225 from
227 my $from = $ua->from;
228 $ua->from('foo@bar.com');
229 Get/set the email address for the human user who controls the
231 requesting user agent. The address should be machine-usable, as
232 defined in RFC2822 <https://tools.ietf.org/html/rfc2822>. The "from"
233 value is sent as the "From" header in the requests.
234 The default is to not send a "From" header. See "default_headers" in
236 LWP::UserAgent for the more general interface that allow any header to
237 be defaulted.
238 local_address
240 my $address = $ua->local_address;
241 $ua->local_address( $address );
242 Get/set the local interface to bind to for network connections. The
244 interface can be specified as a hostname or an IP address. This value
245 is passed as the "LocalAddr" argument to IO::Socket::INET.
246 max_redirect
248 my $max = $ua->max_redirect;
249 $ua->max_redirect( $n );
250 This reads or sets the object's limit of how many times it will obey
252 redirection responses in a given request cycle.
253 By default, the value is 7. This means that if you call "request" in
255 LWP::UserAgent and the response is a redirect elsewhere which is in
256 turn a redirect, and so on seven times, then LWP gives up after that
257 seventh request.
258 max_size
260 my $size = $ua->max_size;
261 $ua->max_size( $bytes );
262 Get/set the size limit for response content. The default is "undef",
264 which means that there is no limit. If the returned response content
265 is only partial, because the size limit was exceeded, then a
266 "Client-Aborted" header will be added to the response. The content
267 might end up longer than "max_size" as we abort once appending a chunk
268 of data makes the length exceed the limit. The "Content-Length"
269 header, if present, will indicate the length of the full content and
270 will normally not be the same as "length($res->content)".
271 parse_head
273 my $bool = $ua->parse_head;
274 $ua->parse_head( $boolean );
275 Get/set a value indicating whether we should initialize response
277 headers from the <head> section of HTML documents. The default is true.
278 Do not turn this off unless you know what you are doing.
279 protocols_allowed
281 my $aref = $ua->protocols_allowed; # get allowed protocols
282 $ua->protocols_allowed( \@protocols ); # allow ONLY these
283 $ua->protocols_allowed(undef); # delete the list
284 $ua->protocols_allowed(['http',]); # ONLY allow http
285 By default, an object has neither a "protocols_allowed" list, nor a
287 "protocols_forbidden" in LWP::UserAgent list.
288 This reads (or sets) this user agent's list of protocols that the
290 request methods will exclusively allow. The protocol names are case
291 insensitive.
292 For example: "$ua->protocols_allowed( [ 'http', 'https'] );" means that
294 this user agent will allow only those protocols, and attempts to use
295 this user agent to access URLs with any other schemes (like
296 "ftp://...") will result in a 500 error.
297 Note that having a "protocols_allowed" list causes any
299 "protocols_forbidden" in LWP::UserAgent list to be ignored.
300 protocols_forbidden
302 my $aref = $ua->protocols_forbidden; # get the forbidden list
303 $ua->protocols_forbidden(\@protocols); # do not allow these
304 $ua->protocols_forbidden(['http',]); # All http reqs get a 500
305 $ua->protocols_forbidden(undef); # delete the list
306 This reads (or sets) this user agent's list of protocols that the
308 request method will not allow. The protocol names are case insensitive.
309 For example: "$ua->protocols_forbidden( [ 'file', 'mailto'] );" means
311 that this user agent will not allow those protocols, and attempts to
312 use this user agent to access URLs with those schemes will result in a
313 500 error.
314 requests_redirectable
316 my $aref = $ua->requests_redirectable;
317 $ua->requests_redirectable( \@requests );
318 $ua->requests_redirectable(['GET', 'HEAD',]); # the default
319 This reads or sets the object's list of request names that
321 "redirect_ok" in LWP::UserAgent will allow redirection for. By default,
322 this is "['GET', 'HEAD']", as per RFC 2616
323 <https://tools.ietf.org/html/rfc2616>. To change to include "POST",
324 consider:
325 push @{ $ua->requests_redirectable }, 'POST';
327 send_te
329 my $bool = $ua->send_te;
330 $ua->send_te( $boolean );
331 If true, will send a "TE" header along with the request. The default is
333 true. Set it to false to disable the "TE" header for systems who can't
334 handle it.
335 show_progress
337 my $bool = $ua->show_progress;
338 $ua->show_progress( $boolean );
339 Get/set a value indicating whether a progress bar should be displayed
341 on the terminal as requests are processed. The default is false.
342 ssl_opts
344 my @keys = $ua->ssl_opts;
345 my $val = $ua->ssl_opts( $key );
346 $ua->ssl_opts( $key => $value );
347 Get/set the options for SSL connections. Without argument return the
349 list of options keys currently set. With a single argument return the
350 current value for the given option. With 2 arguments set the option
351 value and return the old. Setting an option to the value "undef"
352 removes this option.
353 The options that LWP relates to are:
355 "verify_hostname" => $bool
357 When TRUE LWP will for secure protocol schemes ensure it connects
358 to servers that have a valid certificate matching the expected
359 hostname. If FALSE no checks are made and you can't be sure that
360 you communicate with the expected peer. The no checks behaviour
361 was the default for libwww-perl-5.837 and earlier releases.
362 This option is initialized from the "PERL_LWP_SSL_VERIFY_HOSTNAME"
364 environment variable. If this environment variable isn't set; then
365 "verify_hostname" defaults to 1.
366 "SSL_ca_file" => $path
368 The path to a file containing Certificate Authority certificates.
369 A default setting for this option is provided by checking the
370 environment variables "PERL_LWP_SSL_CA_FILE" and "HTTPS_CA_FILE" in
371 order.
372 "SSL_ca_path" => $path
374 The path to a directory containing files containing Certificate
375 Authority certificates. A default setting for this option is
376 provided by checking the environment variables
377 "PERL_LWP_SSL_CA_PATH" and "HTTPS_CA_DIR" in order.
378 Other options can be set and are processed directly by the SSL Socket
380 implementation in use. See IO::Socket::SSL or Net::SSL for details.
381 The libwww-perl core no longer bundles protocol plugins for SSL. You
383 will need to install LWP::Protocol::https separately to enable support
384 for processing https-URLs.
385 timeout
387 my $secs = $ua->timeout;
388 $ua->timeout( $secs );
389 Get/set the timeout value in seconds. The default value is 180 seconds,
391 i.e. 3 minutes.
392 The request is aborted if no activity on the connection to the server
394 is observed for "timeout" seconds. This means that the time it takes
395 for the complete transaction and the "request" in LWP::UserAgent method
396 to actually return might be longer.
397 When a request times out, a response object is still returned. The
399 response will have a standard HTTP Status Code (500). This response
400 will have the "Client-Warning" header set to the value of "Internal
401 response". See the "get" in LWP::UserAgent method description below
402 for further details.
403
405 The following methods set up when requests should be passed via a proxy
406 server.
407 env_proxy
409 $ua->env_proxy;
410 Load proxy settings from *_proxy environment variables. You might
412 specify proxies like this (sh-syntax):
413 gopher_proxy=http://proxy.my.place/
415 wais_proxy=http://proxy.my.place/
416 no_proxy="localhost,example.com"
417 export gopher_proxy wais_proxy no_proxy
418 csh or tcsh users should use the "setenv" command to define these
420 environment variables.
421 On systems with case insensitive environment variables there exists a
423 name clash between the CGI environment variables and the "HTTP_PROXY"
424 environment variable normally picked up by "env_proxy". Because of
425 this "HTTP_PROXY" is not honored for CGI scripts. The "CGI_HTTP_PROXY"
426 environment variable can be used instead.
427 no_proxy
429 $ua->no_proxy( @domains );
430 $ua->no_proxy('localhost', 'example.com');
431 $ua->no_proxy(); # clear the list
432 Do not proxy requests to the given domains. Calling "no_proxy" without
434 any domains clears the list of domains.
435 proxy
437 $ua->proxy(\@schemes, $proxy_url)
438 $ua->proxy(['http', 'ftp'], 'http://proxy.sn.no:8001/');
439 # For a single scheme:
441 $ua->proxy($scheme, $proxy_url)
442 $ua->proxy('gopher', 'http://proxy.sn.no:8001/');
443 # To set multiple proxies at once:
445 $ua->proxy([
446 ftp => 'http://ftp.example.com:8001/',
447 [ 'http', 'https' ] => 'http://http.example.com:8001/',
448 ]);
449 Set/retrieve proxy URL for a scheme.
451 The first form specifies that the URL is to be used as a proxy for
453 access methods listed in the list in the first method argument, i.e.
454 "http" and "ftp".
455 The second form shows a shorthand form for specifying proxy URL for a
457 single access scheme.
458 The third form demonstrates setting multiple proxies at once. This is
460 also the only form accepted by the constructor.
461
463 Handlers are code that injected at various phases during the processing
464 of requests. The following methods are provided to manage the active
465 handlers:
466 add_handler
468 $ua->add_handler( $phase => \&cb, %matchspec )
469 Add handler to be invoked in the given processing phase. For how to
471 specify %matchspec see "Matching" in HTTP::Config.
472 The possible values $phase and the corresponding callback signatures
474 are as follows. Note that the handlers are documented in the order in
475 which they will be run, which is:
476 request_preprepare
478 request_prepare
479 request_send
480 response_header
481 response_data
482 response_done
483 response_redirect
484 request_preprepare => sub { my($request, $ua, $handler) = @_; ... }
486 The handler is called before the "request_prepare" and other
487 standard initialization of the request. This can be used to set up
488 headers and attributes that the "request_prepare" handler depends
489 on. Proxy initialization should take place here; but in general
490 don't register handlers for this phase.
491 request_prepare => sub { my($request, $ua, $handler) = @_; ... }
493 The handler is called before the request is sent and can modify the
494 request any way it see fit. This can for instance be used to add
495 certain headers to specific requests.
496 The method can assign a new request object to $_[0] to replace the
498 request that is sent fully.
499 The return value from the callback is ignored. If an exception is
501 raised it will abort the request and make the request method return
502 a "400 Bad request" response.
503 request_send => sub { my($request, $ua, $handler) = @_; ... }
505 This handler gets a chance of handling requests before they're sent
506 to the protocol handlers. It should return an HTTP::Response
507 object if it wishes to terminate the processing; otherwise it
508 should return nothing.
509 The "response_header" and "response_data" handlers will not be
511 invoked for this response, but the "response_done" will be.
512 response_header => sub { my($response, $ua, $handler) = @_; ... }
514 This handler is called right after the response headers have been
515 received, but before any content data. The handler might set up
516 handlers for data and might croak to abort the request.
517 The handler might set the "$response->{default_add_content}" value
519 to control if any received data should be added to the response
520 object directly. This will initially be false if the
521 "$ua->request()" method was called with a $content_file or
522 "$content_cb argument"; otherwise true.
523 response_data => sub { my($response, $ua, $handler, $data) = @_; ... }
525 This handler is called for each chunk of data received for the
526 response. The handler might croak to abort the request.
527 This handler needs to return a TRUE value to be called again for
529 subsequent chunks for the same request.
530 response_done => sub { my($response, $ua, $handler) = @_; ... }
532 The handler is called after the response has been fully received,
533 but before any redirect handling is attempted. The handler can be
534 used to extract information or modify the response.
535 response_redirect => sub { my($response, $ua, $handler) = @_; ... }
537 The handler is called in "$ua->request" after "response_done". If
538 the handler returns an HTTP::Request object we'll start over with
539 processing this request instead.
540 For all of these, $handler is a code reference to the handler that is
542 currently being run.
543 get_my_handler
545 $ua->get_my_handler( $phase, %matchspec );
546 $ua->get_my_handler( $phase, %matchspec, $init );
547 Will retrieve the matching handler as hash ref.
549 If $init is passed as a true value, create and add the handler if it's
551 not found. If $init is a subroutine reference, then it's called with
552 the created handler hash as argument. This sub might populate the hash
553 with extra fields; especially the callback. If $init is a hash
554 reference, merge the hashes.
555 handlers
557 $ua->handlers( $phase, $request )
558 $ua->handlers( $phase, $response )
559 Returns the handlers that apply to the given request or response at the
561 given processing phase.
562 remove_handler
564 $ua->remove_handler( undef, %matchspec );
565 $ua->remove_handler( $phase, %matchspec );
566 $ua->remove_handler(); # REMOVE ALL HANDLERS IN ALL PHASES
567 Remove handlers that match the given %matchspec. If $phase is not
569 provided, remove handlers from all phases.
570 Be careful as calling this function with %matchspec that is not
572 specific enough can remove handlers not owned by you. It's probably
573 better to use the "set_my_handler" in LWP::UserAgent method instead.
574 The removed handlers are returned.
576 set_my_handler
578 $ua->set_my_handler( $phase, $cb, %matchspec );
579 $ua->set_my_handler($phase, undef); # remove handler for phase
580 Set handlers private to the executing subroutine. Works by defaulting
582 an "owner" field to the %matchspec that holds the name of the called
583 subroutine. You might pass an explicit "owner" to override this.
584 If $cb is passed as "undef", remove the handler.
586
588 The methods described in this section are used to dispatch requests via
589 the user agent. The following request methods are provided:
590 delete
592 my $res = $ua->delete( $url );
593 my $res = $ua->delete( $url, $field_name => $value, ... );
594 This method will dispatch a "DELETE" request on the given URL.
596 Additional headers and content options are the same as for the "get" in
597 LWP::UserAgent method.
598 This method will use the DELETE() function from HTTP::Request::Common
600 to build the request. See HTTP::Request::Common for a details on how
601 to pass form content and other advanced features.
602 get
604 my $res = $ua->get( $url );
605 my $res = $ua->get( $url , $field_name => $value, ... );
606 This method will dispatch a "GET" request on the given URL. Further
608 arguments can be given to initialize the headers of the request. These
609 are given as separate name/value pairs. The return value is a response
610 object. See HTTP::Response for a description of the interface it
611 provides.
612 There will still be a response object returned when LWP can't connect
614 to the server specified in the URL or when other failures in protocol
615 handlers occur. These internal responses use the standard HTTP status
616 codes, so the responses can't be differentiated by testing the response
617 status code alone. Error responses that LWP generates internally will
618 have the "Client-Warning" header set to the value "Internal response".
619 If you need to differentiate these internal responses from responses
620 that a remote server actually generates, you need to test this header
621 value.
622 Fields names that start with ":" are special. These will not
624 initialize headers of the request but will determine how the response
625 content is treated. The following special field names are recognized:
626 ':content_file' => $filename
628 ':content_cb' => \&callback
629 ':read_size_hint' => $bytes
630 If a $filename is provided with the ":content_file" option, then the
632 response content will be saved here instead of in the response object.
633 If a callback is provided with the ":content_cb" option then this
634 function will be called for each chunk of the response content as it is
635 received from the server. If neither of these options are given, then
636 the response content will accumulate in the response object itself.
637 This might not be suitable for very large response bodies. Only one of
638 ":content_file" or ":content_cb" can be specified. The content of
639 unsuccessful responses will always accumulate in the response object
640 itself, regardless of the ":content_file" or ":content_cb" options
641 passed in. Note that errors writing to the content file (for example
642 due to permission denied or the filesystem being full) will be reported
643 via the "Client-Aborted" or "X-Died" response headers, and not the
644 "is_success" method.
645 The ":read_size_hint" option is passed to the protocol module which
647 will try to read data from the server in chunks of this size. A
648 smaller value for the ":read_size_hint" will result in a higher number
649 of callback invocations.
650 The callback function is called with 3 arguments: a chunk of data, a
652 reference to the response object, and a reference to the protocol
653 object. The callback can abort the request by invoking die(). The
654 exception message will show up as the "X-Died" header field in the
655 response returned by the get() function.
656 head
658 my $res = $ua->head( $url );
659 my $res = $ua->head( $url , $field_name => $value, ... );
660 This method will dispatch a "HEAD" request on the given URL. Otherwise
662 it works like the "get" in LWP::UserAgent method described above.
663 is_protocol_supported
665 my $bool = $ua->is_protocol_supported( $scheme );
666 You can use this method to test whether this user agent object supports
668 the specified "scheme". (The "scheme" might be a string (like "http"
669 or "ftp") or it might be an URI object reference.)
670 Whether a scheme is supported is determined by the user agent's
672 "protocols_allowed" or "protocols_forbidden" lists (if any), and by the
673 capabilities of LWP. I.e., this will return true only if LWP supports
674 this protocol and it's permitted for this particular object.
675 is_online
677 my $bool = $ua->is_online;
678 Tries to determine if you have access to the Internet. Returns 1 (true)
680 if the built-in heuristics determine that the user agent is able to
681 access the Internet (over HTTP) or 0 (false).
682 See also LWP::Online.
684 mirror
686 my $res = $ua->mirror( $url, $filename );
687 This method will get the document identified by URL and store it in
689 file called $filename. If the file already exists, then the request
690 will contain an "If-Modified-Since" header matching the modification
691 time of the file. If the document on the server has not changed since
692 this time, then nothing happens. If the document has been updated, it
693 will be downloaded again. The modification time of the file will be
694 forced to match that of the server.
695 The return value is an HTTP::Response object.
697 patch
699 # Any version of HTTP::Message works with this form:
700 my $res = $ua->patch( $url, $field_name => $value, Content => $content );
701 # Using hash or array references requires HTTP::Message >= 6.12
703 use HTTP::Request 6.12;
704 my $res = $ua->patch( $url, \%form );
705 my $res = $ua->patch( $url, \@form );
706 my $res = $ua->patch( $url, \%form, $field_name => $value, ... );
707 my $res = $ua->patch( $url, $field_name => $value, Content => \%form );
708 my $res = $ua->patch( $url, $field_name => $value, Content => \@form );
709 This method will dispatch a "PATCH" request on the given URL, with
711 %form or @form providing the key/value pairs for the fill-in form
712 content. Additional headers and content options are the same as for the
713 "get" in LWP::UserAgent method.
714 CAVEAT:
716 This method can only accept content that is in key-value pairs when
718 using HTTP::Request::Common prior to version 6.12. Any use of hash or
719 array references will result in an error prior to version 6.12.
720 This method will use the "PATCH" function from HTTP::Request::Common to
722 build the request. See HTTP::Request::Common for a details on how to
723 pass form content and other advanced features.
724 post
726 my $res = $ua->post( $url, \%form );
727 my $res = $ua->post( $url, \@form );
728 my $res = $ua->post( $url, \%form, $field_name => $value, ... );
729 my $res = $ua->post( $url, $field_name => $value, Content => \%form );
730 my $res = $ua->post( $url, $field_name => $value, Content => \@form );
731 my $res = $ua->post( $url, $field_name => $value, Content => $content );
732 This method will dispatch a "POST" request on the given URL, with %form
734 or @form providing the key/value pairs for the fill-in form content.
735 Additional headers and content options are the same as for the "get" in
736 LWP::UserAgent method.
737 This method will use the "POST" function from HTTP::Request::Common to
739 build the request. See HTTP::Request::Common for a details on how to
740 pass form content and other advanced features.
741 put
743 # Any version of HTTP::Message works with this form:
744 my $res = $ua->put( $url, $field_name => $value, Content => $content );
745 # Using hash or array references requires HTTP::Message >= 6.07
747 use HTTP::Request 6.07;
748 my $res = $ua->put( $url, \%form );
749 my $res = $ua->put( $url, \@form );
750 my $res = $ua->put( $url, \%form, $field_name => $value, ... );
751 my $res = $ua->put( $url, $field_name => $value, Content => \%form );
752 my $res = $ua->put( $url, $field_name => $value, Content => \@form );
753 This method will dispatch a "PUT" request on the given URL, with %form
755 or @form providing the key/value pairs for the fill-in form content.
756 Additional headers and content options are the same as for the "get" in
757 LWP::UserAgent method.
758 CAVEAT:
760 This method can only accept content that is in key-value pairs when
762 using HTTP::Request::Common prior to version 6.07. Any use of hash or
763 array references will result in an error prior to version 6.07.
764 This method will use the "PUT" function from HTTP::Request::Common to
766 build the request. See HTTP::Request::Common for a details on how to
767 pass form content and other advanced features.
768 request
770 my $res = $ua->request( $request );
771 my $res = $ua->request( $request, $content_file );
772 my $res = $ua->request( $request, $content_cb );
773 my $res = $ua->request( $request, $content_cb, $read_size_hint );
774 This method will dispatch the given $request object. Normally this will
776 be an instance of the HTTP::Request class, but any object with a
777 similar interface will do. The return value is an HTTP::Response
778 object.
779 The "request" method will process redirects and authentication
781 responses transparently. This means that it may actually send several
782 simple requests via the "simple_request" in LWP::UserAgent method
783 described below.
784 The request methods described above; "get" in LWP::UserAgent, "head" in
786 LWP::UserAgent, "post" in LWP::UserAgent and "mirror" in LWP::UserAgent
787 will all dispatch the request they build via this method. They are
788 convenience methods that simply hide the creation of the request object
789 for you.
790 The $content_file, $content_cb and $read_size_hint all correspond to
792 options described with the "get" in LWP::UserAgent method above. Note
793 that errors writing to the content file (for example due to permission
794 denied or the filesystem being full) will be reported via the
795 "Client-Aborted" or "X-Died" response headers, and not the "is_success"
796 method.
797 You are allowed to use a CODE reference as "content" in the request
799 object passed in. The "content" function should return the content
800 when called. The content can be returned in chunks. The content
801 function will be invoked repeatedly until it return an empty string to
802 signal that there is no more content.
803 simple_request
805 my $request = HTTP::Request->new( ... );
806 my $res = $ua->simple_request( $request );
807 my $res = $ua->simple_request( $request, $content_file );
808 my $res = $ua->simple_request( $request, $content_cb );
809 my $res = $ua->simple_request( $request, $content_cb, $read_size_hint );
810 This method dispatches a single request and returns the response
812 received. Arguments are the same as for the "request" in
813 LWP::UserAgent described above.
814 The difference from "request" in LWP::UserAgent is that
816 "simple_request" will not try to handle redirects or authentication
817 responses. The "request" in LWP::UserAgent method will, in fact,
818 invoke this method for each simple request it sends.
819
821 The following methods will be invoked as requests are processed. These
822 methods are documented here because subclasses of LWP::UserAgent might
823 want to override their behaviour.
824 get_basic_credentials
826 # This checks wantarray and can either return an array:
827 my ($user, $pass) = $ua->get_basic_credentials( $realm, $uri, $isproxy );
828 # or a string that looks like "user:pass"
829 my $creds = $ua->get_basic_credentials($realm, $uri, $isproxy);
830 This is called by "request" in LWP::UserAgent to retrieve credentials
832 for documents protected by Basic or Digest Authentication. The
833 arguments passed in is the $realm provided by the server, the $uri
834 requested and a "boolean flag" to indicate if this is authentication
835 against a proxy server.
836 The method should return a username and password. It should return an
838 empty list to abort the authentication resolution attempt. Subclasses
839 can override this method to prompt the user for the information. An
840 example of this can be found in "lwp-request" program distributed with
841 this library.
842 The base implementation simply checks a set of pre-stored member
844 variables, set up with the "credentials" in LWP::UserAgent method.
845 prepare_request
847 $request = $ua->prepare_request( $request );
848 This method is invoked by "simple_request" in LWP::UserAgent. Its task
850 is to modify the given $request object by setting up various headers
851 based on the attributes of the user agent. The return value should
852 normally be the $request object passed in. If a different request
853 object is returned it will be the one actually processed.
854 The headers affected by the base implementation are; "User-Agent",
856 "From", "Range" and "Cookie".
857 progress
859 my $prog = $ua->progress( $status, $request_or_response );
860 This is called frequently as the response is received regardless of how
862 the content is processed. The method is called with $status "begin" at
863 the start of processing the request and with $state "end" before the
864 request method returns. In between these $status will be the fraction
865 of the response currently received or the string "tick" if the fraction
866 can't be calculated.
867 When $status is "begin" the second argument is the HTTP::Request
869 object, otherwise it is the HTTP::Response object.
870 redirect_ok
872 my $bool = $ua->redirect_ok( $prospective_request, $response );
873 This method is called by "request" in LWP::UserAgent before it tries to
875 follow a redirection to the request in $response. This should return a
876 true value if this redirection is permissible. The
877 $prospective_request will be the request to be sent if this method
878 returns true.
879 The base implementation will return false unless the method is in the
881 object's "requests_redirectable" list, false if the proposed
882 redirection is to a "file://..." URL, and true otherwise.
883
885 The default settings can get you up and running quickly, but there are
886 settings you can change in order to make your life easier.
887 Handling Cookies
889 You are encouraged to install Mozilla::PublicSuffix and use
890 HTTP::CookieJar::LWP as your cookie jar. HTTP::CookieJar::LWP provides
891 a better security model matching that of current Web browsers when
892 Mozilla::PublicSuffix is installed.
893 use HTTP::CookieJar::LWP ();
895 my $jar = HTTP::CookieJar::LWP->new;
897 my $ua = LWP::UserAgent->new( cookie_jar => $jar );
898 See "cookie_jar" for more information.
900 Managing Protocols
902 "protocols_allowed" gives you the ability to whitelist the protocols
903 you're willing to allow.
904 my $ua = LWP::UserAgent->new(
906 protocols_allowed => [ 'http', 'https' ]
907 );
908 This will prevent you from inadvertently following URLs like
910 "file:///etc/passwd". See "protocols_allowed".
911 "protocols_forbidden" gives you the ability to blacklist the protocols
913 you're unwilling to allow.
914 my $ua = LWP::UserAgent->new(
916 protocols_forbidden => [ 'file', 'mailto', 'ssh', ]
917 );
918 This can also prevent you from inadvertently following URLs like
920 "file:///etc/passwd". See "protocols_forbidden".
921
923 See LWP for a complete overview of libwww-perl5. See lwpcook and the
924 scripts lwp-request and lwp-download for examples of usage.
925 See HTTP::Request and HTTP::Response for a description of the message
927 objects dispatched and received. See HTTP::Request::Common and
928 HTML::Form for other ways to build request objects.
929 See WWW::Mechanize and WWW::Search for examples of more specialized
931 user agents based on LWP::UserAgent.
932
934 Copyright 1995-2009 Gisle Aas.
935 This library is free software; you can redistribute it and/or modify it
937 under the same terms as Perl itself.
938perl v5.30.2 2020-04-15 LWP::UserAgent(3)