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+package URI::Escape;
+
+use strict;
+use warnings;
+
+=head1 NAME
+
+URI::Escape - Percent-encode and percent-decode unsafe characters
+
+=head1 SYNOPSIS
+
+ use URI::Escape;
+ $safe = uri_escape("10% is enough\n");
+ $verysafe = uri_escape("foo", "\0-\377");
+ $str  = uri_unescape($safe);
+
+=head1 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 I<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:
+
+=over 4
+
+=item uri_escape( $string )
+
+=item 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
+I<not> part of the C<unreserved> character class shown above as well
+as the reserved characters.  I.e. the default is:
+
+    "^A-Za-z0-9\-\._~"
+
+=item uri_escape_utf8( $string )
+
+=item 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().
+
+=item 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($1))/eg;
+
+but does not modify the string in-place as this RE would.  Using the
+uri_unescape() function instead of the RE might make the code look
+cleaner and is a few characters less to type.
+
+In a simple benchmark test I did,
+calling the function (instead of the inline RE above) if a few chars
+were unescaped was something like 40% slower, and something like 700% slower if none were.  If
+you are going to unescape a lot of times it might be a good idea to
+inline the RE.
+
+If the uri_unescape() function is passed multiple strings, then each
+one is returned unescaped.
+
+=back
+
+The module can also export the C<%escapes> hash, which contains the
+mapping from all 256 bytes to the corresponding escape codes.  Lookup
+in this hash is faster than evaluating C<sprintf("%%%02X", ord($byte))>
+each time.
+
+=head1 SEE ALSO
+
+L<URI>
+
+
+=head1 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.
+
+=cut
+
+use Exporter 5.57 'import';
+our %escapes;
+our @EXPORT = qw(uri_escape uri_unescape uri_escape_utf8);
+our @EXPORT_OK = qw(%escapes);
+our $VERSION = "3.31";
+
+use Carp ();
+
+# Build a char->hex map
+for (0..255) {
+    $escapes{chr($_)} = sprintf("%%%02X", $_);
+}
+
+my %subst;  # compiled patterns
+
+my %Unsafe = (
+    RFC2732 => qr/[^A-Za-z0-9\-_.!~*'()]/,
+    RFC3986 => qr/[^A-Za-z0-9\-\._~]/,
+);
+
+sub uri_escape {
+    my($text, $patn) = @_;
+    return undef unless defined $text;
+    if (defined $patn){
+        unless (exists  $subst{$patn}) {
+            # Because we can't compile the regex we fake it with a cached sub
+            (my $tmp = $patn) =~ s,/,\\/,g;
+            eval "\$subst{\$patn} = sub {\$_[0] =~ s/([$tmp])/\$escapes{\$1} || _fail_hi(\$1)/ge; }";
+            Carp::croak("uri_escape: $@") if $@;
+        }
+        &{$subst{$patn}}($text);
+    } else {
+        $text =~ s/($Unsafe{RFC3986})/$escapes{$1} || _fail_hi($1)/ge;
+    }
+    $text;
+}
+
+sub _fail_hi {
+    my $chr = shift;
+    Carp::croak(sprintf "Can't escape \\x{%04X}, try uri_escape_utf8() instead", ord($chr));
+}
+
+sub uri_escape_utf8 {
+    my $text = shift;
+    utf8::encode($text);
+    return uri_escape($text, @_);
+}
+
+sub uri_unescape {
+    # Note from RFC1630:  "Sequences which start with a percent sign
+    # but are not followed by two hexadecimal characters are reserved
+    # for future extension"
+    my $str = shift;
+    if (@_ && wantarray) {
+        # not executed for the common case of a single argument
+        my @str = ($str, @_);  # need to copy
+        for (@str) {
+            s/%([0-9A-Fa-f]{2})/chr(hex($1))/eg;
+        }
+        return @str;
+    }
+    $str =~ s/%([0-9A-Fa-f]{2})/chr(hex($1))/eg if defined $str;
+    $str;
+}
+
+# XXX FIXME escape_char is buggy as it assigns meaning to the string's storage format.
+sub escape_char {
+    # Old versions of utf8::is_utf8() didn't properly handle magical vars (e.g. $1).
+    # The following forces a fetch to occur beforehand.
+    my $dummy = substr($_[0], 0, 0);
+
+    if (utf8::is_utf8($_[0])) {
+        my $s = shift;
+        utf8::encode($s);
+        unshift(@_, $s);
+    }
+
+    return join '', @URI::Escape::escapes{split //, $_[0]};
+}
+
+1;