1URI(3) User Contributed Perl Documentation URI(3)
2
6 URI - Uniform Resource Identifiers (absolute and relative)
7
9 use URI ();
10 $u1 = URI->new("http://www.example.com");
12 $u2 = URI->new("foo", "http");
13 $u3 = $u2->abs($u1);
14 $u4 = $u3->clone;
15 $u5 = URI->new("HTTP://WWW.example.com:80")->canonical;
16 $str = $u->as_string;
18 $str = "$u";
19 $scheme = $u->scheme;
21 $opaque = $u->opaque;
22 $path = $u->path;
23 $frag = $u->fragment;
24 $u->scheme("ftp");
26 $u->host("ftp.example.com");
27 $u->path("cpan/");
28
30 This module implements the "URI" class. Objects of this class
31 represent "Uniform Resource Identifier references" as specified in RFC
32 2396 (and updated by RFC 2732).
33 A Uniform Resource Identifier is a compact string of characters that
35 identifies an abstract or physical resource. A Uniform Resource
36 Identifier can be further classified as either a Uniform Resource
37 Locator (URL) or a Uniform Resource Name (URN). The distinction
38 between URL and URN does not matter to the "URI" class interface. A
39 "URI-reference" is a URI that may have additional information attached
40 in the form of a fragment identifier.
41 An absolute URI reference consists of three parts: a scheme, a scheme-
43 specific part and a fragment identifier. A subset of URI references
44 share a common syntax for hierarchical namespaces. For these, the
45 scheme-specific part is further broken down into authority, path and
46 query components. These URIs can also take the form of relative URI
47 references, where the scheme (and usually also the authority) component
48 is missing, but implied by the context of the URI reference. The three
49 forms of URI reference syntax are summarized as follows:
50 <scheme>:<scheme-specific-part>#<fragment>
52 <scheme>://<authority><path>?<query>#<fragment>
53 <path>?<query>#<fragment>
54 The components into which a URI reference can be divided depend on the
56 scheme. The "URI" class provides methods to get and set the individual
57 components. The methods available for a specific "URI" object depend
58 on the scheme.
59
61 The following methods construct new "URI" objects:
62 $uri = URI->new( $str )
64 $uri = URI->new( $str, $scheme )
65 Constructs a new URI object. The string representation of a URI is
66 given as argument, together with an optional scheme specification.
67 Common URI wrappers like "" and <>, as well as leading and trailing
68 white space, are automatically removed from the $str argument
69 before it is processed further.
70 The constructor determines the scheme, maps this to an appropriate
72 URI subclass, constructs a new object of that class and returns it.
73 If the scheme isn't one of those that URI recognizes, you still get
75 an URI object back that you can access the generic methods on. The
76 "$uri->has_recognized_scheme" method can be used to test for this.
77 The $scheme argument is only used when $str is a relative URI. It
79 can be either a simple string that denotes the scheme, a string
80 containing an absolute URI reference, or an absolute "URI" object.
81 If no $scheme is specified for a relative URI $str, then $str is
82 simply treated as a generic URI (no scheme-specific methods
83 available).
84 The set of characters available for building URI references is
86 restricted (see URI::Escape). Characters outside this set are
87 automatically escaped by the URI constructor.
88 $uri = URI->new_abs( $str, $base_uri )
90 Constructs a new absolute URI object. The $str argument can denote
91 a relative or absolute URI. If relative, then it is absolutized
92 using $base_uri as base. The $base_uri must be an absolute URI.
93 $uri = URI::file->new( $filename )
95 $uri = URI::file->new( $filename, $os )
96 Constructs a new file URI from a file name. See URI::file.
97 $uri = URI::file->new_abs( $filename )
99 $uri = URI::file->new_abs( $filename, $os )
100 Constructs a new absolute file URI from a file name. See
101 URI::file.
102 $uri = URI::file->cwd
104 Returns the current working directory as a file URI. See
105 URI::file.
106 $uri->clone
108 Returns a copy of the $uri.
109
111 The methods described in this section are available for all "URI"
112 objects.
113 Methods that give access to components of a URI always return the old
115 value of the component. The value returned is "undef" if the component
116 was not present. There is generally a difference between a component
117 that is empty (represented as "") and a component that is missing
118 (represented as "undef"). If an accessor method is given an argument,
119 it updates the corresponding component in addition to returning the old
120 value of the component. Passing an undefined argument removes the
121 component (if possible). The description of each accessor method
122 indicates whether the component is passed as an escaped (percent-
123 encoded) or an unescaped string. A component that can be further
124 divided into sub-parts are usually passed escaped, as unescaping might
125 change its semantics.
126 The common methods available for all URI are:
128 $uri->scheme
130 $uri->scheme( $new_scheme )
131 Sets and returns the scheme part of the $uri. If the $uri is
132 relative, then $uri->scheme returns "undef". If called with an
133 argument, it updates the scheme of $uri, possibly changing the
134 class of $uri, and returns the old scheme value. The method croaks
135 if the new scheme name is illegal; a scheme name must begin with a
136 letter and must consist of only US-ASCII letters, numbers, and a
137 few special marks: ".", "+", "-". This restriction effectively
138 means that the scheme must be passed unescaped. Passing an
139 undefined argument to the scheme method makes the URI relative (if
140 possible).
141 Letter case does not matter for scheme names. The string returned
143 by $uri->scheme is always lowercase. If you want the scheme just
144 as it was written in the URI in its original case, you can use the
145 $uri->_scheme method instead.
146 $uri->has_recognized_scheme
148 Returns TRUE if the URI scheme is one that URI recognizes.
149 It will also be TRUE for relative URLs where a recognized scheme
151 was provided to the constructor, even if "$uri->scheme" returns
152 "undef" for these.
153 $uri->opaque
155 $uri->opaque( $new_opaque )
156 Sets and returns the scheme-specific part of the $uri (everything
157 between the scheme and the fragment) as an escaped string.
158 $uri->path
160 $uri->path( $new_path )
161 Sets and returns the same value as $uri->opaque unless the URI
162 supports the generic syntax for hierarchical namespaces. In that
163 case the generic method is overridden to set and return the part of
164 the URI between the host name and the fragment.
165 $uri->fragment
167 $uri->fragment( $new_frag )
168 Returns the fragment identifier of a URI reference as an escaped
169 string.
170 $uri->as_string
172 Returns a URI object to a plain ASCII string. URI objects are also
173 converted to plain strings automatically by overloading. This
174 means that $uri objects can be used as plain strings in most Perl
175 constructs.
176 $uri->as_iri
178 Returns a Unicode string representing the URI. Escaped UTF-8
179 sequences representing non-ASCII characters are turned into their
180 corresponding Unicode code point.
181 $uri->canonical
183 Returns a normalized version of the URI. The rules for
184 normalization are scheme-dependent. They usually involve
185 lowercasing the scheme and Internet host name components, removing
186 the explicit port specification if it matches the default port,
187 uppercasing all escape sequences, and unescaping octets that can be
188 better represented as plain characters.
189 For efficiency reasons, if the $uri is already in normalized form,
191 then a reference to it is returned instead of a copy.
192 $uri->eq( $other_uri )
194 URI::eq( $first_uri, $other_uri )
195 Tests whether two URI references are equal. URI references that
196 normalize to the same string are considered equal. The method can
197 also be used as a plain function which can also test two string
198 arguments.
199 If you need to test whether two "URI" object references denote the
201 same object, use the '==' operator.
202 $uri->abs( $base_uri )
204 Returns an absolute URI reference. If $uri is already absolute,
205 then a reference to it is simply returned. If the $uri is
206 relative, then a new absolute URI is constructed by combining the
207 $uri and the $base_uri, and returned.
208 $uri->rel( $base_uri )
210 Returns a relative URI reference if it is possible to make one that
211 denotes the same resource relative to $base_uri. If not, then $uri
212 is simply returned.
213 $uri->secure
215 Returns a TRUE value if the URI is considered to point to a
216 resource on a secure channel, such as an SSL or TLS encrypted one.
217
219 The following methods are available to schemes that use the
220 common/generic syntax for hierarchical namespaces. The descriptions of
221 schemes below indicate which these are. Unrecognized schemes are
222 assumed to support the generic syntax, and therefore the following
223 methods:
224 $uri->authority
226 $uri->authority( $new_authority )
227 Sets and returns the escaped authority component of the $uri.
228 $uri->path
230 $uri->path( $new_path )
231 Sets and returns the escaped path component of the $uri (the part
232 between the host name and the query or fragment). The path can
233 never be undefined, but it can be the empty string.
234 $uri->path_query
236 $uri->path_query( $new_path_query )
237 Sets and returns the escaped path and query components as a single
238 entity. The path and the query are separated by a "?" character,
239 but the query can itself contain "?".
240 $uri->path_segments
242 $uri->path_segments( $segment, ... )
243 Sets and returns the path. In a scalar context, it returns the
244 same value as $uri->path. In a list context, it returns the
245 unescaped path segments that make up the path. Path segments that
246 have parameters are returned as an anonymous array. The first
247 element is the unescaped path segment proper; subsequent elements
248 are escaped parameter strings. Such an anonymous array uses
249 overloading so it can be treated as a string too, but this string
250 does not include the parameters.
251 Note that absolute paths have the empty string as their first
253 path_segment, i.e. the path "/foo/bar" have 3 path_segments; "",
254 "foo" and "bar".
255 $uri->query
257 $uri->query( $new_query )
258 Sets and returns the escaped query component of the $uri.
259 $uri->query_form
261 $uri->query_form( $key1 => $val1, $key2 => $val2, ... )
262 $uri->query_form( $key1 => $val1, $key2 => $val2, ..., $delim )
263 $uri->query_form( \@key_value_pairs )
264 $uri->query_form( \@key_value_pairs, $delim )
265 $uri->query_form( \%hash )
266 $uri->query_form( \%hash, $delim )
267 Sets and returns query components that use the
268 application/x-www-form-urlencoded format. Key/value pairs are
269 separated by "&", and the key is separated from the value by a "="
270 character.
271 The form can be set either by passing separate key/value pairs, or
273 via an array or hash reference. Passing an empty array or an empty
274 hash removes the query component, whereas passing no arguments at
275 all leaves the component unchanged. The order of keys is undefined
276 if a hash reference is passed. The old value is always returned as
277 a list of separate key/value pairs. Assigning this list to a hash
278 is unwise as the keys returned might repeat.
279 The values passed when setting the form can be plain strings or
281 references to arrays of strings. Passing an array of values has
282 the same effect as passing the key repeatedly with one value at a
283 time. All the following statements have the same effect:
284 $uri->query_form(foo => 1, foo => 2);
286 $uri->query_form(foo => [1, 2]);
287 $uri->query_form([ foo => 1, foo => 2 ]);
288 $uri->query_form([ foo => [1, 2] ]);
289 $uri->query_form({ foo => [1, 2] });
290 The $delim parameter can be passed as ";" to force the key/value
292 pairs to be delimited by ";" instead of "&" in the query string.
293 This practice is often recommended for URLs embedded in HTML or XML
294 documents as this avoids the trouble of escaping the "&" character.
295 You might also set the $URI::DEFAULT_QUERY_FORM_DELIMITER variable
296 to ";" for the same global effect.
297 @keys = $u->query_param
299 @values = $u->query_param( $key )
300 $first_value = $u->query_param( $key )
301 $u->query_param( $key, $value,... )
302 If $u->query_param is called with no arguments, it returns all the
303 distinct parameter keys of the URI. In a scalar context it returns
304 the number of distinct keys.
305 When a $key argument is given, the method returns the parameter
307 values with the given key. In a scalar context, only the first
308 parameter value is returned.
309 If additional arguments are given, they are used to update
311 successive parameters with the given key. If any of the values
312 provided are array references, then the array is dereferenced to
313 get the actual values.
314 Please note that you can supply multiple values to this method, but
316 you cannot supply multiple keys.
317 Do this:
319 $uri->query_param( widget_id => 1, 5, 9 );
321 Do NOT do this:
323 $uri->query_param( widget_id => 1, frobnicator_id => 99 );
325 $u->query_param_append($key, $value,...)
327 Adds new parameters with the given key without touching any old
328 parameters with the same key. It can be explained as a more
329 efficient version of:
330 $u->query_param($key,
332 $u->query_param($key),
333 $value,...);
334 One difference is that this expression would return the old values
336 of $key, whereas the query_param_append() method does not.
337 @values = $u->query_param_delete($key)
339 $first_value = $u->query_param_delete($key)
340 Deletes all key/value pairs with the given key. The old values are
341 returned. In a scalar context, only the first value is returned.
342 Using the query_param_delete() method is slightly more efficient
344 than the equivalent:
345 $u->query_param($key, []);
347 $hashref = $u->query_form_hash
349 $u->query_form_hash( \%new_form )
350 Returns a reference to a hash that represents the query form's
351 key/value pairs. If a key occurs multiple times, then the hash
352 value becomes an array reference.
353 Note that sequence information is lost. This means that:
355 $u->query_form_hash($u->query_form_hash);
357 is not necessarily a no-op, as it may reorder the key/value pairs.
359 The values returned by the query_param() method should stay the
360 same though.
361 $uri->query_keywords
363 $uri->query_keywords( $keywords, ... )
364 $uri->query_keywords( \@keywords )
365 Sets and returns query components that use the keywords separated
366 by "+" format.
367 The keywords can be set either by passing separate keywords
369 directly or by passing a reference to an array of keywords.
370 Passing an empty array removes the query component, whereas passing
371 no arguments at all leaves the component unchanged. The old value
372 is always returned as a list of separate words.
373
375 For schemes where the authority component denotes an Internet host, the
376 following methods are available in addition to the generic methods.
377 $uri->userinfo
379 $uri->userinfo( $new_userinfo )
380 Sets and returns the escaped userinfo part of the authority
381 component.
382 For some schemes this is a user name and a password separated by a
384 colon. This practice is not recommended. Embedding passwords in
385 clear text (such as URI) has proven to be a security risk in almost
386 every case where it has been used.
387 $uri->host
389 $uri->host( $new_host )
390 Sets and returns the unescaped hostname.
391 If the $new_host string ends with a colon and a number, then this
393 number also sets the port.
394 For IPv6 addresses the brackets around the raw address is removed
396 in the return value from $uri->host. When setting the host
397 attribute to an IPv6 address you can use a raw address or one
398 enclosed in brackets. The address needs to be enclosed in brackets
399 if you want to pass in a new port value as well.
400 $uri->ihost
402 Returns the host in Unicode form. Any IDNA A-labels are turned
403 into U-labels.
404 $uri->port
406 $uri->port( $new_port )
407 Sets and returns the port. The port is a simple integer that
408 should be greater than 0.
409 If a port is not specified explicitly in the URI, then the URI
411 scheme's default port is returned. If you don't want the default
412 port substituted, then you can use the $uri->_port method instead.
413 $uri->host_port
415 $uri->host_port( $new_host_port )
416 Sets and returns the host and port as a single unit. The returned
417 value includes a port, even if it matches the default port. The
418 host part and the port part are separated by a colon: ":".
419 For IPv6 addresses the bracketing is preserved; thus
421 URI->new("http://[::1]/")->host_port returns "[::1]:80". Contrast
422 this with $uri->host which will remove the brackets.
423 $uri->default_port
425 Returns the default port of the URI scheme to which $uri belongs.
426 For http this is the number 80, for ftp this is the number 21, etc.
427 The default port for a scheme can not be changed.
428
430 Scheme-specific support is provided for the following URI schemes. For
431 "URI" objects that do not belong to one of these, you can only use the
432 common and generic methods.
433 data:
435 The data URI scheme is specified in RFC 2397. It allows inclusion
436 of small data items as "immediate" data, as if it had been included
437 externally.
438 "URI" objects belonging to the data scheme support the common
440 methods and two new methods to access their scheme-specific
441 components: $uri->media_type and $uri->data. See URI::data for
442 details.
443 file:
445 An old specification of the file URI scheme is found in RFC 1738.
446 A new RFC 2396 based specification in not available yet, but file
447 URI references are in common use.
448 "URI" objects belonging to the file scheme support the common and
450 generic methods. In addition, they provide two methods for mapping
451 file URIs back to local file names; $uri->file and $uri->dir. See
452 URI::file for details.
453 ftp:
455 An old specification of the ftp URI scheme is found in RFC 1738. A
456 new RFC 2396 based specification in not available yet, but ftp URI
457 references are in common use.
458 "URI" objects belonging to the ftp scheme support the common,
460 generic and server methods. In addition, they provide two methods
461 for accessing the userinfo sub-components: $uri->user and
462 $uri->password.
463 gopher:
465 The gopher URI scheme is specified in
466 <draft-murali-url-gopher-1996-12-04> and will hopefully be
467 available as a RFC 2396 based specification.
468 "URI" objects belonging to the gopher scheme support the common,
470 generic and server methods. In addition, they support some methods
471 for accessing gopher-specific path components: $uri->gopher_type,
472 $uri->selector, $uri->search, $uri->string.
473 http:
475 The http URI scheme is specified in RFC 2616. The scheme is used
476 to reference resources hosted by HTTP servers.
477 "URI" objects belonging to the http scheme support the common,
479 generic and server methods.
480 https:
482 The https URI scheme is a Netscape invention which is commonly
483 implemented. The scheme is used to reference HTTP servers through
484 SSL connections. Its syntax is the same as http, but the default
485 port is different.
486 ldap:
488 The ldap URI scheme is specified in RFC 2255. LDAP is the
489 Lightweight Directory Access Protocol. An ldap URI describes an
490 LDAP search operation to perform to retrieve information from an
491 LDAP directory.
492 "URI" objects belonging to the ldap scheme support the common,
494 generic and server methods as well as ldap-specific methods:
495 $uri->dn, $uri->attributes, $uri->scope, $uri->filter,
496 $uri->extensions. See URI::ldap for details.
497 ldapi:
499 Like the ldap URI scheme, but uses a UNIX domain socket. The
500 server methods are not supported, and the local socket path is
501 available as $uri->un_path. The ldapi scheme is used by the
502 OpenLDAP package. There is no real specification for it, but it is
503 mentioned in various OpenLDAP manual pages.
504 ldaps:
506 Like the ldap URI scheme, but uses an SSL connection. This scheme
507 is deprecated, as the preferred way is to use the start_tls
508 mechanism.
509 mailto:
511 The mailto URI scheme is specified in RFC 2368. The scheme was
512 originally used to designate the Internet mailing address of an
513 individual or service. It has (in RFC 2368) been extended to allow
514 setting of other mail header fields and the message body.
515 "URI" objects belonging to the mailto scheme support the common
517 methods and the generic query methods. In addition, they support
518 the following mailto-specific methods: $uri->to, $uri->headers.
519 Note that the "foo@example.com" part of a mailto is not the
521 "userinfo" and "host" but instead the "path". This allows a mailto
522 URI to contain multiple comma separated email addresses.
523 mms:
525 The mms URL specification can be found at <http://sdp.ppona.com/>.
526 "URI" objects belonging to the mms scheme support the common,
527 generic, and server methods, with the exception of userinfo and
528 query-related sub-components.
529 news:
531 The news, nntp and snews URI schemes are specified in
532 <draft-gilman-news-url-01> and will hopefully be available as an
533 RFC 2396 based specification soon. (Update: as of April 2010, they
534 are in RFC 5538 <https://tools.ietf.org/html/rfc5538>.
535 "URI" objects belonging to the news scheme support the common,
537 generic and server methods. In addition, they provide some methods
538 to access the path: $uri->group and $uri->message.
539 nntp:
541 See news scheme.
542 nntps:
544 See news scheme and RFC 5538 <https://tools.ietf.org/html/rfc5538>.
545 pop:
547 The pop URI scheme is specified in RFC 2384. The scheme is used to
548 reference a POP3 mailbox.
549 "URI" objects belonging to the pop scheme support the common,
551 generic and server methods. In addition, they provide two methods
552 to access the userinfo components: $uri->user and $uri->auth
553 rlogin:
555 An old specification of the rlogin URI scheme is found in RFC 1738.
556 "URI" objects belonging to the rlogin scheme support the common,
557 generic and server methods.
558 rtsp:
560 The rtsp URL specification can be found in section 3.2 of RFC 2326.
561 "URI" objects belonging to the rtsp scheme support the common,
562 generic, and server methods, with the exception of userinfo and
563 query-related sub-components.
564 rtspu:
566 The rtspu URI scheme is used to talk to RTSP servers over UDP
567 instead of TCP. The syntax is the same as rtsp.
568 rsync:
570 Information about rsync is available from
571 <http://rsync.samba.org/>. "URI" objects belonging to the rsync
572 scheme support the common, generic and server methods. In
573 addition, they provide methods to access the userinfo sub-
574 components: $uri->user and $uri->password.
575 sip:
577 The sip URI specification is described in sections 19.1 and 25 of
578 RFC 3261. "URI" objects belonging to the sip scheme support the
579 common, generic, and server methods with the exception of path
580 related sub-components. In addition, they provide two methods to
581 get and set sip parameters: $uri->params_form and $uri->params.
582 sips:
584 See sip scheme. Its syntax is the same as sip, but the default
585 port is different.
586 snews:
588 See news scheme. Its syntax is the same as news, but the default
589 port is different.
590 telnet:
592 An old specification of the telnet URI scheme is found in RFC 1738.
593 "URI" objects belonging to the telnet scheme support the common,
594 generic and server methods.
595 tn3270:
597 These URIs are used like telnet URIs but for connections to IBM
598 mainframes. "URI" objects belonging to the tn3270 scheme support
599 the common, generic and server methods.
600 ssh:
602 Information about ssh is available at <http://www.openssh.com/>.
603 "URI" objects belonging to the ssh scheme support the common,
604 generic and server methods. In addition, they provide methods to
605 access the userinfo sub-components: $uri->user and $uri->password.
606 sftp:
608 "URI" objects belonging to the sftp scheme support the common,
609 generic and server methods. In addition, they provide methods to
610 access the userinfo sub-components: $uri->user and $uri->password.
611 urn:
613 The syntax of Uniform Resource Names is specified in RFC 2141.
614 "URI" objects belonging to the urn scheme provide the common
615 methods, and also the methods $uri->nid and $uri->nss, which return
616 the Namespace Identifier and the Namespace-Specific String
617 respectively.
618 The Namespace Identifier basically works like the Scheme identifier
620 of URIs, and further divides the URN namespace. Namespace
621 Identifier assignments are maintained at
622 <http://www.iana.org/assignments/urn-namespaces>.
623 Letter case is not significant for the Namespace Identifier. It is
625 always returned in lower case by the $uri->nid method. The
626 $uri->_nid method can be used if you want it in its original case.
627 urn:isbn:
629 The "urn:isbn:" namespace contains International Standard Book
630 Numbers (ISBNs) and is described in RFC 3187. A "URI" object
631 belonging to this namespace has the following extra methods (if the
632 Business::ISBN module is available): $uri->isbn,
633 $uri->isbn_publisher_code, $uri->isbn_group_code (formerly
634 isbn_country_code, which is still supported by issues a deprecation
635 warning), $uri->isbn_as_ean.
636 urn:oid:
638 The "urn:oid:" namespace contains Object Identifiers (OIDs) and is
639 described in RFC 3061. An object identifier consists of sequences
640 of digits separated by dots. A "URI" object belonging to this
641 namespace has an additional method called $uri->oid that can be
642 used to get/set the oid value. In a list context, oid numbers are
643 returned as separate elements.
644
646 The following configuration variables influence how the class and its
647 methods behave:
648 $URI::ABS_ALLOW_RELATIVE_SCHEME
650 Some older parsers used to allow the scheme name to be present in
651 the relative URL if it was the same as the base URL scheme. RFC
652 2396 says that this should be avoided, but you can enable this old
653 behaviour by setting the $URI::ABS_ALLOW_RELATIVE_SCHEME variable
654 to a TRUE value. The difference is demonstrated by the following
655 examples:
656 URI->new("http:foo")->abs("http://host/a/b")
658 ==> "http:foo"
659 local $URI::ABS_ALLOW_RELATIVE_SCHEME = 1;
661 URI->new("http:foo")->abs("http://host/a/b")
662 ==> "http:/host/a/foo"
663 $URI::ABS_REMOTE_LEADING_DOTS
665 You can also have the abs() method ignore excess ".." segments in
666 the relative URI by setting $URI::ABS_REMOTE_LEADING_DOTS to a TRUE
667 value. The difference is demonstrated by the following examples:
668 URI->new("../../../foo")->abs("http://host/a/b")
670 ==> "http://host/../../foo"
671 local $URI::ABS_REMOTE_LEADING_DOTS = 1;
673 URI->new("../../../foo")->abs("http://host/a/b")
674 ==> "http://host/foo"
675 $URI::DEFAULT_QUERY_FORM_DELIMITER
677 This value can be set to ";" to have the query form "key=value"
678 pairs delimited by ";" instead of "&" which is the default.
679
681 URI_HAS_RESERVED_SQUARE_BRACKETS
682 Before version 5.11, URI treated square brackets as reserved
683 characters throughout the whole URI string. However, these brackets
684 are reserved only within the authority/host part of the URI and
685 nowhere else (RFC 3986).
686 Starting with version 5.11, URI takes this distinction into
688 account. Setting the environment variable
689 "URI_HAS_RESERVED_SQUARE_BRACKETS" (programmatically or via the
690 shell), restores the old behavior.
691 #-- restore 5.10 behavior programmatically
693 BEGIN {
694 $ENV{URI_HAS_RESERVED_SQUARE_BRACKETS} = 1;
695 }
696 use URI ();
697 Note: This environment variable is just used during initialization
699 and has to be set
700 before module URI is used/required. Changing it at run time
701 has no effect.
702 Its value can be checked programmatically by accessing the constant
704 "URI::HAS_RESERVED_SQUARE_BRACKETS".
705
707 There are some things that are not quite right:
708 • Using regexp variables like $1 directly as arguments to the URI
710 accessor methods does not work too well with current perl
711 implementations. I would argue that this is actually a bug in
712 perl. The workaround is to quote them. Example:
713 /(...)/ || die;
715 $u->query("$1");
716 • The escaping (percent encoding) of chars in the 128 .. 255 range
718 passed to the URI constructor or when setting URI parts using the
719 accessor methods depend on the state of the internal UTF8 flag (see
720 utf8::is_utf8) of the string passed. If the UTF8 flag is set the
721 UTF-8 encoded version of the character is percent encoded. If the
722 UTF8 flag isn't set the Latin-1 version (byte) of the character is
723 percent encoded. This basically exposes the internal encoding of
724 Perl strings.
725
727 As an alternative to this module, the following (official) regular
728 expression can be used to decode a URI:
729 my($scheme, $authority, $path, $query, $fragment) =
731 $uri =~ m|(?:([^:/?#]+):)?(?://([^/?#]*))?([^?#]*)(?:\?([^#]*))?(?:#(.*))?|;
732 The "URI::Split" module provides the function uri_split() as a readable
734 alternative.
735
737 URI::file, URI::WithBase, URI::Escape, URI::Split, URI::Heuristic
738 RFC 2396: "Uniform Resource Identifiers (URI): Generic Syntax",
740 Berners-Lee, Fielding, Masinter, August 1998.
741 <http://www.iana.org/assignments/uri-schemes>
743 <http://www.iana.org/assignments/urn-namespaces>
745 <http://www.w3.org/Addressing/>
747
749 Copyright 1995-2009 Gisle Aas.
750 Copyright 1995 Martijn Koster.
752 This program is free software; you can redistribute it and/or modify it
754 under the same terms as Perl itself.
755
757 This module is based on the "URI::URL" module, which in turn was
758 (distantly) based on the "wwwurl.pl" code in the libwww-perl for perl4
759 developed by Roy Fielding, as part of the Arcadia project at the
760 University of California, Irvine, with contributions from Brooks
761 Cutter.
762 "URI::URL" was developed by Gisle Aas, Tim Bunce, Roy Fielding and
764 Martijn Koster with input from other people on the libwww-perl mailing
765 list.
766 "URI" and related subclasses was developed by Gisle Aas.
768perl v5.36.0 2023-01-20 URI(3)