File::Truncate::Undoable - Truncate a file, with undo support


This document describes version 0.04 of File::Truncate::Undoable (from Perl distribution File-Truncate-Undoable), released on 2015-09-03.




truncate(%args) -> [status, msg, result, meta]

Truncate a file, with undo support.

On do, will trash file then create an empty file (with the same permission and ownership as the original). On undo, will trash the new file and untrash the old file.

Note: chown will not be done if we are not running as root. Symlink is currently not permitted.

Fixed state: file exists and size is not zero.

Fixable state: file exists and size is not zero.

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

Special arguments:

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.

Return value: (any)


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