On Apache
Under GNU General Public License
2024-04-19 07:06 @18.224.59.231 CrawledBy Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
URI::Escape(3pm) User Contributed Perl Documentation URI::Escape(3pm)
NAME
URI::Escape - Percent-encode and percent-decode unsafe characters
SYNOPSIS
use URI::Escape;
$safe = uri_escape("10% is enough\n");
$verysafe = uri_escape("foo", "\0-\377");
$str = uri_unescape($safe);
DESCRIPTION
This module provides functions to percent-encode and percent-decode URI strings as defined
by RFC 3986. Percent-encoding URI's is informally called "URI escaping". This is the
terminology used by this module, which predates the formalization of the terms by the RFC
by several years.
A URI consists of a restricted set of characters. The restricted set of characters
consists of digits, letters, and a few graphic symbols chosen from those common to most of
the character encodings and input facilities available to Internet users. They are made
up of the "unreserved" and "reserved" character sets as defined in RFC 3986.
unreserved = ALPHA / DIGIT / "-" / "." / "_" / "~"
reserved = ":" / "/" / "?" / "#" / "[" / "]" / "@"
"!" / "$" / "&" / "'" / "(" / ")"
/ "*" / "+" / "," / ";" / "="
In addition, any byte (octet) can be represented in a URI by an escape sequence: a triplet
consisting of the character "%" followed by two hexadecimal digits. A byte can also be
represented directly by a character, using the US-ASCII character for that octet.
Some of the characters are reserved for use as delimiters or as part of certain URI
components. These must be escaped if they are to be treated as ordinary data. Read RFC
3986 for further details.
The functions provided (and exported by default) from this module are:
uri_escape( $string )
uri_escape( $string, $unsafe )
Replaces each unsafe character in the $string with the corresponding escape sequence
and returns the result. The $string argument should be a string of bytes. The
uri_escape() function will croak if given a characters with code above 255. Use
uri_escape_utf8() if you know you have such chars or/and want chars in the 128 .. 255
range treated as UTF-8.
The uri_escape() function takes an optional second argument that overrides the set of
characters that are to be escaped. The set is specified as a string that can be used
in a regular expression character class (between [ ]). E.g.:
"\x00-\x1f\x7f-\xff" # all control and hi-bit characters
"a-z" # all lower case characters
"^A-Za-z" # everything not a letter
The default set of characters to be escaped is all those which are not part of the
"unreserved" character class shown above as well as the reserved characters. I.e. the
default is:
"^A-Za-z0-9\-\._~"
uri_escape_utf8( $string )
uri_escape_utf8( $string, $unsafe )
Works like uri_escape(), but will encode chars as UTF-8 before escaping them. This
makes this function able to deal with characters with code above 255 in $string. Note
that chars in the 128 .. 255 range will be escaped differently by this function
compared to what uri_escape() would. For chars in the 0 .. 127 range there is no
difference.
Equivalent to:
utf8::encode($string);
my $uri = uri_escape($string);
Note: JavaScript has a function called escape() that produces the sequence "%uXXXX"
for chars in the 256 .. 65535 range. This function has really nothing to do with URI
escaping but some folks got confused since it "does the right thing" in the 0 .. 255
range. Because of this you sometimes see "URIs" with these kind of escapes. The
JavaScript encodeURIComponent() function is similar to uri_escape_utf8().
uri_unescape($string,...)
Returns a string with each %XX sequence replaced with the actual byte (octet).
This does the same as:
$string =~ s/%([0-9A-Fa-f]{2})/chr(hex($1))/eg;
but does not modify the string in-place as this RE would. Using the uri_unescape()
function instead of the RE might make the code look cleaner and is a few characters
less to type.
In a simple benchmark test I did, calling the function (instead of the inline RE
above) if a few chars were unescaped was something like 40% slower, and something like
700% slower if none were. If you are going to unescape a lot of times it might be a
good idea to inline the RE.
If the uri_unescape() function is passed multiple strings, then each one is returned
unescaped.
The module can also export the %escapes hash, which contains the mapping from all 256
bytes to the corresponding escape codes. Lookup in this hash is faster than evaluating
"sprintf("%%%02X", ord($byte))" each time.
SEE ALSO
URI
COPYRIGHT
Copyright 1995-2004 Gisle Aas.
This program is free software; you can redistribute it and/or modify it under the same
terms as Perl itself.
perl v5.30.0 2020-02-08 URI::Escape(3pm)
Generated by $Id: phpMan.php,v 4.55 2007/09/05 04:42:51 chedong Exp $ Author: Che Dong
On Apache
Under GNU General Public License
2024-04-19 07:06 @18.224.59.231 CrawledBy Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)