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URI::Escape(3)        User Contributed Perl Documentation       URI::Escape(3)

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 v5.16.3                      2012-02-11                    URI::Escape(3)