URI::Escape - man - phpMan

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.