NAME
    File::Prepend::Undoable - Prepend string to a file, with undo support

VERSION
    version 0.01

SEE ALSO
    Rinci::Transaction

DESCRIPTION
    This module has Rinci metadata.

FUNCTIONS
    None are exported by default, but they are exportable.

  prepend(%args) -> [status, msg, result, meta]
    Prepend string to a file, with undo support.

    On do, will trash file, copy it to original location (with the same
    permission and ownership as the original) and prepend the string to the
    beginning of file. On undo will trash the new file and untrash the
    original.

    Some notes:

    *   Chown will not be done if we are not running as root.

    *   Symlink is currently not permitted.

    *   Since transaction requires the function to be idempotent, in the
        "check_state" phase the function will check if the string has been
        prepended. It will refuse to prepend the same string twice.

    *   Take care not to use string that are too large, as the string, being
        a function parameter, is entered into the transaction table.

    Fixed state: file exists and string has been prepended to beginning of
    file.

    Fixable state: file exists and string has not been prepended to
    beginning of file.

    Unfixable state: file does not exist or path is not a regular file
    (directory and symlink included).

    This function is idempotent (repeated invocations with same arguments
    has the same effect as single invocation). This function supports
    transactions.

    Arguments ('*' denotes required arguments):

    *   path* => *str*

        The file to prepend.

    *   string* => *any*

        The string to prepend to file.

    Special arguments:

    *   -tx_action => *str*

        For more information on transaction, see Rinci::Transaction.

    *   -tx_action_id => *str*

        For more information on transaction, see Rinci::Transaction.

    *   -tx_recovery => *str*

        For more information on transaction, see Rinci::Transaction.

    *   -tx_rollback => *str*

        For more information on transaction, see Rinci::Transaction.

    *   -tx_v => *str*

        For more information on transaction, see Rinci::Transaction.

    Return value:

    Returns an enveloped result (an array). First element (status) is an
    integer containing HTTP status code (200 means OK, 4xx caller error, 5xx
    function error). Second element (msg) is a string containing error
    message, or 'OK' if status is 200. Third element (result) is optional,
    the actual result. Fourth element (meta) is called result metadata and
    is optional, a hash that contains extra information.

AUTHOR
    Steven Haryanto <stevenharyanto@gmail.com>

COPYRIGHT AND LICENSE
    This software is copyright (c) 2012 by Steven Haryanto.

    This is free software; you can redistribute it and/or modify it under
    the same terms as the Perl 5 programming language system itself.