NAME
    CPAN::Checksums - Write a "CHECKSUMS" file for a directory as on CPAN

SYNOPSIS
      use CPAN::Checksums qw(updatedir);
      my $success = updatedir($directory);

INCOMPATIBILITY ALERT
    Since version 1.0 the generation of the attribute "shortname" is turned
    off by default. It was too slow and was not used as far as I know, and
    above all, it could fail on large directories. The shortname feature can
    still be turned on by setting the global variable $TRY_SHORTNAME to a
    true value.

DESCRIPTION
    $success = updatedir($dir)
      "updatedir()" takes a directory name as argument and writes a typical
      "CHECKSUMS" file in that directory as used on CPAN unless a previously
      written "CHECKSUMS" file is there that is still valid. Returns 2 if a
      new "CHECKSUMS" file has been written, 1 if a valid "CHECKSUMS" file
      is already there, otherwise dies.

      Note: since version 2.0 updatedir on empty directories behaves just
      the same. In older versions it silently did nothing.

  Global Variables in package CPAN::Checksums
    $IGNORE_MATCH
        If the global variable $IGNORE_MATCH is set, then all files matching
        this expression will be completely ignored and will not be included
        in the CPAN "CHECKSUMS" files. Per default this variable is set to

            qr{(?i-xsm:readme$)}

    $CAUTION
        Setting the global variable $CAUTION causes updatedir() to report
        changes of files in the attributes "size", "mtime", "md5", or
        "md5-ungz" to STDERR.

    $TRY_SHORTNAME
        By setting the global variable $TRY_SHORTNAME to a true value, you
        can tell updatedir() to include an attribute "shortname" in the
        resulting hash that is 8.3-compatible. Please note, that updatedir()
        in this case may be slow and may even fail on large directories,
        because it will always only try 1000 iterations to find a name that
        is not yet taken and then give up.

    $SIGNING_KEY
        Setting the global variable $SIGNING_KEY makes the generated
        "CHECKSUMS" file to be clear-signed by the command specified in
        $SIGNING_PROGRAM (defaults to "gpg --clearsign --default-key "),
        passing the signing key as an extra argument. The resulting
        "CHECKSUMS" file should look like:

            0&&<<''; # this PGP-signed message is also valid perl
            -----BEGIN PGP SIGNED MESSAGE-----
            Hash: SHA1

            # CHECKSUMS file written on ... by CPAN::Checksums (v...)
            $cksum = {
                ...
            };

            __END__
            -----BEGIN PGP SIGNATURE-----
            ...
            -----END PGP SIGNATURE-----

        note that the actual data remains intact, but two extra lines are
        added to make it legal for both OpenPGP and perl syntax.

    $MIN_MTIME_CHECKSUMS
        If the global variable $MIN_MTIME_CHECKSUMS is set, then updatedir
        will renew signatures on checksum files that have an older mtime
        than the given value.

PREREQUISITES
    DirHandle, IO::File, Digest::MD5, Digest::SHA, Compress::Bzip2,
    Compress::Zlib, File::Spec, Data::Dumper, Data::Compare, File::Temp

BUGS
    If updatedir is interrupted, it may leave a temporary file lying around.
    These files have the File::Temp template "CHECKSUMS.XXXX" and should be
    harvested by a cronjob.

AUTHOR
    Andreas Koenig, andreas.koenig@anima.de; GnuPG support by Autrijus Tang

COPYRIGHT & LICENSE
    Copyright (c) 2002-2008 Andreas Koenig, Audrey Tang, Steve Peters.

    This program is free software; you can redistribute it and/or modify it
    under the same terms as Perl itself.

SEE ALSO
    perl(1).