NAME

       Regexp::Common::URI::ftp -- Returns a pattern for FTP URIs.

SYNOPSIS

           use Regexp::Common qw /URI/;

           while (<>) {
               /$RE{URI}{FTP}/       and  print "Contains an FTP URI.\n";
           }

DESCRIPTION

   $RE{URI}{FTP}{-type}{-password};
       Returns a regex for FTP URIs. Note: FTP URIs are not formally defined.  RFC 1738 defines FTP URLs, but
       parts of that RFC have been obsoleted by RFC 2396. However, the differences between RFC 1738 and RFC 2396
       are such that they aren't applicable straightforwardly to FTP URIs.

       There are two main problems:

       Passwords.
           RFC 1738 allowed an optional username and an optional password (separated by a colon) in the FTP URL.
           Hence,  colons  were not allowed in either the username or the password. RFC 2396 strongly recommends
           passwords should not be used in URIs. It does allow for userinfo  instead.  This  userinfo  part  may
           contain  colons,  and  hence  contain  more  than one colon. The regexp returned follows the RFC 2396
           specification, unless the {-password} option is given; then the regex allows for an optional username
           and password, separated by a colon.

       The ;type specifier.
           RFC 1738 does not allow semi-colons in FTP path names, because a semi-colon is a  reserved  character
           for FTP URIs. The semi-colon is used to separate the path from the option type specifier. However, in
           RFC 2396, paths consist of slash separated segments, and each segment is a semi-colon separated group
           of  parameters.  Straigthforward  application  of  RFC 2396 would mean that a trailing type specifier
           couldn't be distinguished from the last segment of the path having a two  parameters,  the  last  one
           starting with type=. Therefore we have opted to disallow a semi-colon in the path part of an FTP URI.

           Furthermore,  RFC  1738  allows three values for the type specifier, A, I and D (either upper case or
           lower case). However, the internet draft about FTP URIs [DRAFT-FTP-URL] (which expired in  May  1997)
           notes  the  lack of consistent implementation of the D parameter and drops D from the set of possible
           values. We follow this practise; however, RFC 1738 behaviour can be archieved by using  the  -type  =
           "[ADIadi]"> parameter.

       FTP URIs have the following syntax:

           "ftp:" "//" [ userinfo "@" ] host [ ":" port ]
                       [ "/" path [ ";type=" value ]]

       When using {-password}, we have the syntax:

           "ftp:" "//" [ user [ ":" password ] "@" ] host [ ":" port ]
                       [ "/" path [ ";type=" value ]]

       Under "{-keep}", the following are returned:

       $1  The complete URI.

       $2  The scheme.

       $3  The userinfo, or if {-password} is used, the username.

       $4  If {-password} is used, the password, else "undef".

       $5  The hostname or IP address.

       $6  The port number.

       $7  The full path and type specification, including the leading slash.

       $8  The full path and type specification, without the leading slash.

       $9  The full path, without the type specification nor the leading slash.

       $10 The value of the type specification.

REFERENCES

       [DRAFT-URL-FTP]
           Casey, James: A FTP URL Format. November 1996.

       [RFC 1738]
           Berners-Lee, Tim, Masinter, L., McCahill, M.: Uniform Resource Locators (URL). December 1994.

       [RFC 2396]
           Berners-Lee, Tim, Fielding, R., and Masinter, L.: Uniform Resource Identifiers (URI): Generic Syntax.
           August 1998.

SEE ALSO

       Regexp::Common::URI for other supported URIs.

AUTHOR

       Damian Conway (damian@conway.org)

MAINTENANCE

       This package is maintained by Abigail (regexp-common@abigail.be).

BUGS AND IRRITATIONS

       Bound to be plenty.

LICENSE and COPYRIGHT

       This software is Copyright (c) 2001 - 2017, Damian Conway and Abigail.

       This module is free software, and maybe used under any of the following licenses:

        1) The Perl Artistic License.     See the file COPYRIGHT.AL.
        2) The Perl Artistic License 2.0. See the file COPYRIGHT.AL2.
        3) The BSD License.               See the file COPYRIGHT.BSD.
        4) The MIT License.               See the file COPYRIGHT.MIT.

perl v5.36.0                                       2022-10-15                      Regexp::Common::URI::ftp(3pm)