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 ();
12 my $ua = LWP::UserAgent->new;
14 $ua->timeout(10);
15 $ua->env_proxy;
16 my $response = $ua->get('http://search.cpan.org/');
18 if ($response->is_success) {
20 print $response->decoded_content; # or whatever
21 }
22 else {
23 die $response->status_line;
24 }
25
27 The LWP::UserAgent is a class implementing a web user agent.
28 LWP::UserAgent objects can be used to dispatch web requests.
29 In normal use the application creates an LWP::UserAgent object, and
31 then configures it with values for timeouts, proxies, name, etc. It
32 then creates an instance of HTTP::Request for the request that needs to
33 be performed. This request is then passed to one of the request method
34 the UserAgent, which dispatches it using the relevant protocol, and
35 returns a HTTP::Response object. There are convenience methods for
36 sending the most common request types: "get" in LWP::UserAgent, "head"
37 in LWP::UserAgent, "post" in LWP::UserAgent, "put" in LWP::UserAgent
38 and "delete" in LWP::UserAgent. When using these methods, the creation
39 of the request object is hidden as shown in the synopsis above.
40 The basic approach of the library is to use HTTP-style communication
42 for all protocol schemes. This means that you will construct
43 HTTP::Request objects and receive HTTP::Response objects even for non-
44 HTTP resources like gopher and ftp. In order to achieve even more
45 similarity to HTTP-style communications, gopher menus and file
46 directories are converted to HTML documents.
47
49 The following constructor methods are available:
50 clone
52 my $ua2 = $ua->clone;
53 Returns a copy of the LWP::UserAgent object.
55 CAVEAT: Please be aware that the clone method does not copy or clone
57 your "cookie_jar" attribute. Due to the limited restrictions on what
58 can be used for your cookie jar, there is no way to clone the
59 attribute. The "cookie_jar" attribute will be "undef" in the new object
60 instance.
61 new
63 my $ua = LWP::UserAgent->new( %options )
64 This method constructs a new LWP::UserAgent object and returns it.
66 Key/value pair arguments may be provided to set up the initial state.
67 The following options correspond to attribute methods described below:
68 KEY DEFAULT
70 ----------- --------------------
71 agent "libwww-perl/#.###"
72 from undef
73 conn_cache undef
74 cookie_jar undef
75 default_headers HTTP::Headers->new
76 local_address undef
77 ssl_opts { verify_hostname => 1 }
78 max_size undef
79 max_redirect 7
80 parse_head 1
81 protocols_allowed undef
82 protocols_forbidden undef
83 requests_redirectable ['GET', 'HEAD']
84 timeout 180
85 proxy undef
86 no_proxy []
87 The following additional options are also accepted: If the "env_proxy"
89 option is passed in with a true value, then proxy settings are read
90 from environment variables (see "env_proxy" in LWP::UserAgent). If
91 "env_proxy" isn't provided, the "PERL_LWP_ENV_PROXY" environment
92 variable controls if "env_proxy" in LWP::UserAgent is called during
93 initialization. If the "keep_alive" option is passed in, then a
94 "LWP::ConnCache" is set up (see "conn_cache" in LWP::UserAgent). The
95 "keep_alive" value is passed on as the "total_capacity" for the
96 connection cache.
97 "proxy" must be set as an arrayref of key/value pairs. "no_proxy" takes
99 an arrayref of domains.
100
102 The settings of the configuration attributes modify the behaviour of
103 the LWP::UserAgent when it dispatches requests. Most of these can also
104 be initialized by options passed to the constructor method.
105 The following attribute methods are provided. The attribute value is
107 left unchanged if no argument is given. The return value from each
108 method is the old attribute value.
109 agent
111 my $agent = $ua->agent;
112 $ua->agent('Checkbot/0.4 '); # append the default to the end
113 $ua->agent('Mozilla/5.0');
114 $ua->agent(""); # don't identify
115 Get/set the product token that is used to identify the user agent on
117 the network. The agent value is sent as the "User-Agent" header in the
118 requests.
119 The default is a string of the form "libwww-perl/#.###", where "#.###"
121 is substituted with the version number of this library.
122 If the provided string ends with space, the default "libwww-perl/#.###"
124 string is appended to it.
125 The user agent string should be one or more simple product identifiers
127 with an optional version number separated by the "/" character.
128 conn_cache
130 my $cache_obj = $ua->conn_cache;
131 $ua->conn_cache( $cache_obj );
132 Get/set the LWP::ConnCache object to use. See LWP::ConnCache for
134 details.
135 cookie_jar
137 my $jar = $ua->cookie_jar;
138 $ua->cookie_jar( $cookie_jar_obj );
139 Get/set the cookie jar object to use. The only requirement is that the
141 cookie jar object must implement the "extract_cookies($response)" and
142 "add_cookie_header($request)" methods. These methods will then be
143 invoked by the user agent as requests are sent and responses are
144 received. Normally this will be a HTTP::Cookies object or some
145 subclass.
146 The default is to have no cookie jar, i.e. never automatically add
148 "Cookie" headers to the requests.
149 Shortcut: If a reference to a plain hash is passed in, it is replaced
151 with an instance of HTTP::Cookies that is initialized based on the
152 hash. This form also automatically loads the HTTP::Cookies module. It
153 means that:
154 $ua->cookie_jar({ file => "$ENV{HOME}/.cookies.txt" });
156 is really just a shortcut for:
158 require HTTP::Cookies;
160 $ua->cookie_jar(HTTP::Cookies->new(file => "$ENV{HOME}/.cookies.txt"));
161 credentials
163 my $creds = $ua->credentials();
164 $ua->credentials( $netloc, $realm );
165 $ua->credentials( $netloc, $realm, $uname, $pass );
166 $ua->credentials("www.example.com:80", "Some Realm", "foo", "secret");
167 Get/set the user name and password to be used for a realm.
169 The $netloc is a string of the form "<host>:<port>". The username and
171 password will only be passed to this server.
172 default_header
174 $ua->default_header( $field );
175 $ua->default_header( $field => $value );
176 $ua->default_header('Accept-Encoding' => scalar HTTP::Message::decodable());
177 $ua->default_header('Accept-Language' => "no, en");
178 This is just a shortcut for "$ua->default_headers->header( $field =>
180 $value )".
181 default_headers
183 my $headers = $ua->default_headers;
184 $ua->default_headers( $headers_obj );
185 Get/set the headers object that will provide default header values for
187 any requests sent. By default this will be an empty HTTP::Headers
188 object.
189 from
191 my $from = $ua->from;
192 $ua->from('foo@bar.com');
193 Get/set the email address for the human user who controls the
195 requesting user agent. The address should be machine-usable, as
196 defined in RFC2822 <https://tools.ietf.org/html/rfc2822>. The "from"
197 value is sent as the "From" header in the requests.
198 The default is to not send a "From" header. See "default_headers" in
200 LWP::UserAgent for the more general interface that allow any header to
201 be defaulted.
202 local_address
204 my $address = $ua->local_address;
205 $ua->local_address( $address );
206 Get/set the local interface to bind to for network connections. The
208 interface can be specified as a hostname or an IP address. This value
209 is passed as the "LocalAddr" argument to IO::Socket::INET.
210 max_redirect
212 my $max = $ua->max_redirect;
213 $ua->max_redirect( $n );
214 This reads or sets the object's limit of how many times it will obey
216 redirection responses in a given request cycle.
217 By default, the value is 7. This means that if you call "request" in
219 LWP::UserAgent and the response is a redirect elsewhere which is in
220 turn a redirect, and so on seven times, then LWP gives up after that
221 seventh request.
222 max_size
224 my $size = $ua->max_size;
225 $ua->max_size( $bytes );
226 Get/set the size limit for response content. The default is "undef",
228 which means that there is no limit. If the returned response content
229 is only partial, because the size limit was exceeded, then a
230 "Client-Aborted" header will be added to the response. The content
231 might end up longer than "max_size" as we abort once appending a chunk
232 of data makes the length exceed the limit. The "Content-Length"
233 header, if present, will indicate the length of the full content and
234 will normally not be the same as "length($res->content)".
235 parse_head
237 my $bool = $ua->parse_head;
238 $ua->parse_head( $boolean );
239 Get/set a value indicating whether we should initialize response
241 headers from the <head> section of HTML documents. The default is true.
242 Do not turn this off unless you know what you are doing.
243 protocols_allowed
245 my $aref = $ua->protocols_allowed; # get allowed protocols
246 $ua->protocols_allowed( \@protocols ); # allow ONLY these
247 $ua->protocols_allowed(undef); # delete the list
248 $ua->protocols_allowed(['http',]); # ONLY allow http
249 By default, an object has neither a "protocols_allowed" list, nor a
251 "protocols_forbidden" in LWP::UserAgent list.
252 This reads (or sets) this user agent's list of protocols that the
254 request methods will exclusively allow. The protocol names are case
255 insensitive.
256 For example: "$ua->protocols_allowed( [ 'http', 'https'] );" means that
258 this user agent will allow only those protocols, and attempts to use
259 this user agent to access URLs with any other schemes (like
260 "ftp://...") will result in a 500 error.
261 Note that having a "protocols_allowed" list causes any
263 "protocols_forbidden" in LWP::UserAgent list to be ignored.
264 protocols_forbidden
266 my $aref = $ua->protocols_forbidden; # get the forbidden list
267 $ua->protocols_forbidden(\@protocols); # do not allow these
268 $ua->protocols_forbidden(['http',]); # All http reqs get a 500
269 $ua->protocols_forbidden(undef); # delete the list
270 This reads (or sets) this user agent's list of protocols that the
272 request method will not allow. The protocol names are case insensitive.
273 For example: "$ua->protocols_forbidden( [ 'file', 'mailto'] );" means
275 that this user agent will not allow those protocols, and attempts to
276 use this user agent to access URLs with those schemes will result in a
277 500 error.
278 requests_redirectable
280 my $aref = $ua->requests_redirectable;
281 $ua->requests_redirectable( \@requests );
282 $ua->requests_redirectable(['GET', 'HEAD',]); # the default
283 This reads or sets the object's list of request names that
285 "redirect_ok" in LWP::UserAgent will allow redirection for. By default,
286 this is "['GET', 'HEAD']", as per RFC 2616
287 <https://tools.ietf.org/html/rfc2616>. To change to include "POST",
288 consider:
289 push @{ $ua->requests_redirectable }, 'POST';
291 send_te
293 my $bool = $ua->send_te;
294 $ua->send_te( $boolean );
295 If true, will send a "TE" header along with the request. The default is
297 true. Set it to false to disable the "TE" header for systems who can't
298 handle it.
299 show_progress
301 my $bool = $ua->show_progress;
302 $ua->show_progress( $boolean );
303 Get/set a value indicating whether a progress bar should be displayed
305 on the terminal as requests are processed. The default is false.
306 ssl_opts
308 my @keys = $ua->ssl_opts;
309 my $val = $ua->ssl_opts( $key );
310 $ua->ssl_opts( $key => $value );
311 Get/set the options for SSL connections. Without argument return the
313 list of options keys currently set. With a single argument return the
314 current value for the given option. With 2 arguments set the option
315 value and return the old. Setting an option to the value "undef"
316 removes this option.
317 The options that LWP relates to are:
319 "verify_hostname" => $bool
321 When TRUE LWP will for secure protocol schemes ensure it connects
322 to servers that have a valid certificate matching the expected
323 hostname. If FALSE no checks are made and you can't be sure that
324 you communicate with the expected peer. The no checks behaviour
325 was the default for libwww-perl-5.837 and earlier releases.
326 This option is initialized from the "PERL_LWP_SSL_VERIFY_HOSTNAME"
328 environment variable. If this environment variable isn't set; then
329 "verify_hostname" defaults to 1.
330 "SSL_ca_file" => $path
332 The path to a file containing Certificate Authority certificates.
333 A default setting for this option is provided by checking the
334 environment variables "PERL_LWP_SSL_CA_FILE" and "HTTPS_CA_FILE" in
335 order.
336 "SSL_ca_path" => $path
338 The path to a directory containing files containing Certificate
339 Authority certificates. A default setting for this option is
340 provided by checking the environment variables
341 "PERL_LWP_SSL_CA_PATH" and "HTTPS_CA_DIR" in order.
342 Other options can be set and are processed directly by the SSL Socket
344 implementation in use. See IO::Socket::SSL or Net::SSL for details.
345 The libwww-perl core no longer bundles protocol plugins for SSL. You
347 will need to install LWP::Protocol::https separately to enable support
348 for processing https-URLs.
349 timeout
351 my $secs = $ua->timeout;
352 $ua->timeout( $secs );
353 Get/set the timeout value in seconds. The default value is 180 seconds,
355 i.e. 3 minutes.
356 The request is aborted if no activity on the connection to the server
358 is observed for "timeout" seconds. This means that the time it takes
359 for the complete transaction and the "request" in LWP::UserAgent method
360 to actually return might be longer.
361 When a request times out, a response object is still returned. The
363 response will have a standard HTTP Status Code (500). This response
364 will have the "Client-Warning" header set to the value of "Internal
365 response". See the "get" in LWP::UserAgent method description below
366 for further details.
367
369 The following methods set up when requests should be passed via a proxy
370 server.
371 env_proxy
373 $ua->env_proxy;
374 Load proxy settings from *_proxy environment variables. You might
376 specify proxies like this (sh-syntax):
377 gopher_proxy=http://proxy.my.place/
379 wais_proxy=http://proxy.my.place/
380 no_proxy="localhost,example.com"
381 export gopher_proxy wais_proxy no_proxy
382 csh or tcsh users should use the "setenv" command to define these
384 environment variables.
385 On systems with case insensitive environment variables there exists a
387 name clash between the CGI environment variables and the "HTTP_PROXY"
388 environment variable normally picked up by "env_proxy". Because of
389 this "HTTP_PROXY" is not honored for CGI scripts. The "CGI_HTTP_PROXY"
390 environment variable can be used instead.
391 no_proxy
393 $ua->no_proxy( @domains );
394 $ua->no_proxy('localhost', 'example.com');
395 $ua->no_proxy(); # clear the list
396 Do not proxy requests to the given domains. Calling "no_proxy" without
398 any domains clears the list of domains.
399 proxy
401 $ua->proxy(\@schemes, $proxy_url)
402 $ua->proxy(['http', 'ftp'], 'http://proxy.sn.no:8001/');
403 # For a single scheme:
405 $ua->proxy($scheme, $proxy_url)
406 $ua->proxy('gopher', 'http://proxy.sn.no:8001/');
407 # To set multiple proxies at once:
409 $ua->proxy([
410 ftp => 'http://ftp.example.com:8001/',
411 [ 'http', 'https' ] => 'http://http.example.com:8001/',
412 ]);
413 Set/retrieve proxy URL for a scheme.
415 The first form specifies that the URL is to be used as a proxy for
417 access methods listed in the list in the first method argument, i.e.
418 "http" and "ftp".
419 The second form shows a shorthand form for specifying proxy URL for a
421 single access scheme.
422 The third form demonstrates setting multiple proxies at once. This is
424 also the only form accepted by the constructor.
425
427 Handlers are code that injected at various phases during the processing
428 of requests. The following methods are provided to manage the active
429 handlers:
430 add_handler
432 $ua->add_handler( $phase => \&cb, %matchspec )
433 Add handler to be invoked in the given processing phase. For how to
435 specify %matchspec see "Matching" in HTTP::Config.
436 The possible values $phase and the corresponding callback signatures
438 are:
439 response_data => sub { my($response, $ua, $h, $data) = @_; ... }
441 This handler is called for each chunk of data received for the
442 response. The handler might croak to abort the request.
443 This handler needs to return a TRUE value to be called again for
445 subsequent chunks for the same request.
446 response_done => sub { my($response, $ua, $h) = @_; ... }
448 The handler is called after the response has been fully received,
449 but before any redirect handling is attempted. The handler can be
450 used to extract information or modify the response.
451 response_header => sub { my($response, $ua, $h) = @_; ... }
453 This handler is called right after the response headers have been
454 received, but before any content data. The handler might set up
455 handlers for data and might croak to abort the request.
456 The handler might set the $response->{default_add_content} value to
458 control if any received data should be added to the response object
459 directly. This will initially be false if the $ua->request()
460 method was called with a $content_file or $content_cb argument;
461 otherwise true.
462 request_prepare => sub { my($request, $ua, $h) = @_; ... }
464 The handler is called before the request is sent and can modify the
465 request any way it see fit. This can for instance be used to add
466 certain headers to specific requests.
467 The method can assign a new request object to $_[0] to replace the
469 request that is sent fully.
470 The return value from the callback is ignored. If an exception is
472 raised it will abort the request and make the request method return
473 a "400 Bad request" response.
474 request_preprepare => sub { my($request, $ua, $h) = @_; ... }
476 The handler is called before the "request_prepare" and other
477 standard initialization of the request. This can be used to set up
478 headers and attributes that the "request_prepare" handler depends
479 on. Proxy initialization should take place here; but in general
480 don't register handlers for this phase.
481 request_send => sub { my($request, $ua, $h) = @_; ... }
483 This handler gets a chance of handling requests before they're sent
484 to the protocol handlers. It should return an HTTP::Response
485 object if it wishes to terminate the processing; otherwise it
486 should return nothing.
487 The "response_header" and "response_data" handlers will not be
489 invoked for this response, but the "response_done" will be.
490 response_redirect => sub { my($response, $ua, $h) = @_; ... }
492 The handler is called in $ua->request after "response_done". If
493 the handler returns an HTTP::Request object we'll start over with
494 processing this request instead.
495 get_my_handler
497 $ua->get_my_handler( $phase, %matchspec );
498 $ua->get_my_handler( $phase, %matchspec, $init );
499 Will retrieve the matching handler as hash ref.
501 If $init is passed as a true value, create and add the handler if it's
503 not found. If $init is a subroutine reference, then it's called with
504 the created handler hash as argument. This sub might populate the hash
505 with extra fields; especially the callback. If $init is a hash
506 reference, merge the hashes.
507 handlers
509 $ua->handlers( $phase, $request )
510 $ua->handlers( $phase, $response )
511 Returns the handlers that apply to the given request or response at the
513 given processing phase.
514 remove_handler
516 $ua->remove_handler( undef, %matchspec );
517 $ua->remove_handler( $phase, %matchspec );
518 $ua->remove_handlers(); # REMOVE ALL HANDLERS IN ALL PHASES
519 Remove handlers that match the given %matchspec. If $phase is not
521 provided, remove handlers from all phases.
522 Be careful as calling this function with %matchspec that is not
524 specific enough can remove handlers not owned by you. It's probably
525 better to use the "set_my_handler" in LWP::UserAgent method instead.
526 The removed handlers are returned.
528 set_my_handler
530 $ua->set_my_handler( $phase, $cb, %matchspec );
531 $ua->set_my_handler($phase, undef); # remove handler for phase
532 Set handlers private to the executing subroutine. Works by defaulting
534 an "owner" field to the %matchspec that holds the name of the called
535 subroutine. You might pass an explicit "owner" to override this.
536 If $cb is passed as "undef", remove the handler.
538
540 The methods described in this section are used to dispatch requests via
541 the user agent. The following request methods are provided:
542 delete
544 my $res = $ua->delete( $url );
545 my $res = $ua->delete( $url, $field_name => $value, ... );
546 This method will dispatch a "DELETE" request on the given URL.
548 Additional headers and content options are the same as for the "get" in
549 LWP::UserAgent method.
550 This method will use the DELETE() function from HTTP::Request::Common
552 to build the request. See HTTP::Request::Common for a details on how
553 to pass form content and other advanced features.
554 get
556 my $res = $ua->get( $url );
557 my $res = $ua->get( $url , $field_name => $value, ... );
558 This method will dispatch a "GET" request on the given URL. Further
560 arguments can be given to initialize the headers of the request. These
561 are given as separate name/value pairs. The return value is a response
562 object. See HTTP::Response for a description of the interface it
563 provides.
564 There will still be a response object returned when LWP can't connect
566 to the server specified in the URL or when other failures in protocol
567 handlers occur. These internal responses use the standard HTTP status
568 codes, so the responses can't be differentiated by testing the response
569 status code alone. Error responses that LWP generates internally will
570 have the "Client-Warning" header set to the value "Internal response".
571 If you need to differentiate these internal responses from responses
572 that a remote server actually generates, you need to test this header
573 value.
574 Fields names that start with ":" are special. These will not
576 initialize headers of the request but will determine how the response
577 content is treated. The following special field names are recognized:
578 :content_file => $filename
580 :content_cb => \&callback
581 :read_size_hint => $bytes
582 If a $filename is provided with the ":content_file" option, then the
584 response content will be saved here instead of in the response object.
585 If a callback is provided with the ":content_cb" option then this
586 function will be called for each chunk of the response content as it is
587 received from the server. If neither of these options are given, then
588 the response content will accumulate in the response object itself.
589 This might not be suitable for very large response bodies. Only one of
590 ":content_file" or ":content_cb" can be specified. The content of
591 unsuccessful responses will always accumulate in the response object
592 itself, regardless of the ":content_file" or ":content_cb" options
593 passed in. Note that errors writing to the content file (for example
594 due to permission denied or the filesystem being full) will be reported
595 via the "Client-Aborted" or "X-Died" response headers, and not the
596 "is_success" method.
597 The ":read_size_hint" option is passed to the protocol module which
599 will try to read data from the server in chunks of this size. A
600 smaller value for the ":read_size_hint" will result in a higher number
601 of callback invocations.
602 The callback function is called with 3 arguments: a chunk of data, a
604 reference to the response object, and a reference to the protocol
605 object. The callback can abort the request by invoking die(). The
606 exception message will show up as the "X-Died" header field in the
607 response returned by the get() function.
608 head
610 my $res = $ua->head( $url );
611 my $res = $ua->head( $url , $field_name => $value, ... );
612 This method will dispatch a "HEAD" request on the given URL. Otherwise
614 it works like the "get" in LWP::UserAgent method described above.
615 is_protocol_supported
617 my $bool = $ua->is_protocol_supported( $scheme );
618 You can use this method to test whether this user agent object supports
620 the specified "scheme". (The "scheme" might be a string (like "http"
621 or "ftp") or it might be an URI object reference.)
622 Whether a scheme is supported is determined by the user agent's
624 "protocols_allowed" or "protocols_forbidden" lists (if any), and by the
625 capabilities of LWP. I.e., this will return true only if LWP supports
626 this protocol and it's permitted for this particular object.
627 is_online
629 my $bool = $ua->is_online;
630 Tries to determine if you have access to the Internet. Returns 1 (true)
632 if the built-in heuristics determine that the user agent is able to
633 access the Internet (over HTTP) or 0 (false).
634 See also LWP::Online.
636 mirror
638 my $res = $ua->mirror( $url, $filename );
639 This method will get the document identified by URL and store it in
641 file called $filename. If the file already exists, then the request
642 will contain an "If-Modified-Since" header matching the modification
643 time of the file. If the document on the server has not changed since
644 this time, then nothing happens. If the document has been updated, it
645 will be downloaded again. The modification time of the file will be
646 forced to match that of the server.
647 The return value is an HTTP::Response object.
649 post
651 my $res = $ua->post( $url, \%form );
652 my $res = $ua->post( $url, \@form );
653 my $res = $ua->post( $url, \%form, $field_name => $value, ... );
654 my $res = $ua->post( $url, $field_name => $value, Content => \%form );
655 my $res = $ua->post( $url, $field_name => $value, Content => \@form );
656 my $res = $ua->post( $url, $field_name => $value, Content => $content );
657 This method will dispatch a "POST" request on the given URL, with %form
659 or @form providing the key/value pairs for the fill-in form content.
660 Additional headers and content options are the same as for the "get" in
661 LWP::UserAgent method.
662 This method will use the "POST" function from HTTP::Request::Common to
664 build the request. See HTTP::Request::Common for a details on how to
665 pass form content and other advanced features.
666 put
668 # Any version of HTTP::Message works with this form:
669 my $res = $ua->put( $url, $field_name => $value, Content => $content );
670 # Using hash or array references requires HTTP::Message >= 6.07
672 use HTTP::Request 6.07;
673 my $res = $ua->put( $url, \%form );
674 my $res = $ua->put( $url, \@form );
675 my $res = $ua->put( $url, \%form, $field_name => $value, ... );
676 my $res = $ua->put( $url, $field_name => $value, Content => \%form );
677 my $res = $ua->put( $url, $field_name => $value, Content => \@form );
678 This method will dispatch a "PUT" request on the given URL, with %form
680 or @form providing the key/value pairs for the fill-in form content.
681 Additional headers and content options are the same as for the "get" in
682 LWP::UserAgent method.
683 CAVEAT:
685 This method can only accept content that is in key-value pairs when
687 using HTTP::Request::Common prior to version 6.07. Any use of hash or
688 array references will result in an error prior to version 6.07.
689 This method will use the "PUT" function from HTTP::Request::Common to
691 build the request. See HTTP::Request::Common for a details on how to
692 pass form content and other advanced features.
693 request
695 my $res = $ua->request( $request );
696 my $res = $ua->request( $request, $content_file );
697 my $res = $ua->request( $request, $content_cb );
698 my $res = $ua->request( $request, $content_cb, $read_size_hint );
699 This method will dispatch the given $request object. Normally this will
701 be an instance of the HTTP::Request class, but any object with a
702 similar interface will do. The return value is an HTTP::Response
703 object.
704 The "request" method will process redirects and authentication
706 responses transparently. This means that it may actually send several
707 simple requests via the "simple_request" in LWP::UserAgent method
708 described below.
709 The request methods described above; "get" in LWP::UserAgent, "head" in
711 LWP::UserAgent, "post" in LWP::UserAgent and "mirror" in LWP::UserAgent
712 will all dispatch the request they build via this method. They are
713 convenience methods that simply hide the creation of the request object
714 for you.
715 The $content_file, $content_cb and $read_size_hint all correspond to
717 options described with the "get" in LWP::UserAgent method above. Note
718 that errors writing to the content file (for example due to permission
719 denied or the filesystem being full) will be reported via the
720 "Client-Aborted" or "X-Died" response headers, and not the "is_success"
721 method.
722 You are allowed to use a CODE reference as "content" in the request
724 object passed in. The "content" function should return the content
725 when called. The content can be returned in chunks. The content
726 function will be invoked repeatedly until it return an empty string to
727 signal that there is no more content.
728 simple_request
730 my $request = HTTP::Request->new( ... );
731 my $res = $ua->simple_request( $request );
732 my $res = $ua->simple_request( $request, $content_file );
733 my $res = $ua->simple_request( $request, $content_cb );
734 my $res = $ua->simple_request( $request, $content_cb, $read_size_hint );
735 This method dispatches a single request and returns the response
737 received. Arguments are the same as for the "request" in
738 LWP::UserAgent described above.
739 The difference from "request" in LWP::UserAgent is that
741 "simple_request" will not try to handle redirects or authentication
742 responses. The "request" in LWP::UserAgent method will, in fact,
743 invoke this method for each simple request it sends.
744
746 The following methods will be invoked as requests are processed. These
747 methods are documented here because subclasses of LWP::UserAgent might
748 want to override their behaviour.
749 get_basic_credentials
751 # This checks wantarray and can either return an array:
752 my ($user, $pass) = $ua->get_basic_credentials( $realm, $uri, $isproxy );
753 # or a string that looks like "user:pass"
754 my $creds = $ua->get_basic_credentials($realm, $uri, $isproxy);
755 This is called by "request" in LWP::UserAgent to retrieve credentials
757 for documents protected by Basic or Digest Authentication. The
758 arguments passed in is the $realm provided by the server, the $uri
759 requested and a "boolean flag" to indicate if this is authentication
760 against a proxy server.
761 The method should return a username and password. It should return an
763 empty list to abort the authentication resolution attempt. Subclasses
764 can override this method to prompt the user for the information. An
765 example of this can be found in "lwp-request" program distributed with
766 this library.
767 The base implementation simply checks a set of pre-stored member
769 variables, set up with the "credentials" in LWP::UserAgent method.
770 prepare_request
772 $request = $ua->prepare_request( $request );
773 This method is invoked by "simple_request" in LWP::UserAgent. Its task
775 is to modify the given $request object by setting up various headers
776 based on the attributes of the user agent. The return value should
777 normally be the $request object passed in. If a different request
778 object is returned it will be the one actually processed.
779 The headers affected by the base implementation are; "User-Agent",
781 "From", "Range" and "Cookie".
782 progress
784 my $prog = $ua->progress( $status, $request_or_response );
785 This is called frequently as the response is received regardless of how
787 the content is processed. The method is called with $status "begin" at
788 the start of processing the request and with $state "end" before the
789 request method returns. In between these $status will be the fraction
790 of the response currently received or the string "tick" if the fraction
791 can't be calculated.
792 When $status is "begin" the second argument is the HTTP::Request
794 object, otherwise it is the HTTP::Response object.
795 redirect_ok
797 my $bool = $ua->redirect_ok( $prospective_request, $response );
798 This method is called by "request" in LWP::UserAgent before it tries to
800 follow a redirection to the request in $response. This should return a
801 true value if this redirection is permissible. The
802 $prospective_request will be the request to be sent if this method
803 returns true.
804 The base implementation will return false unless the method is in the
806 object's "requests_redirectable" list, false if the proposed
807 redirection is to a "file://..." URL, and true otherwise.
808
810 See LWP for a complete overview of libwww-perl5. See lwpcook and the
811 scripts lwp-request and lwp-download for examples of usage.
812 See HTTP::Request and HTTP::Response for a description of the message
814 objects dispatched and received. See HTTP::Request::Common and
815 HTML::Form for other ways to build request objects.
816 See WWW::Mechanize and WWW::Search for examples of more specialized
818 user agents based on LWP::UserAgent.
819
821 Copyright 1995-2009 Gisle Aas.
822 This library is free software; you can redistribute it and/or modify it
824 under the same terms as Perl itself.
825perl v5.28.0 2018-07-16 LWP::UserAgent(3)