# Dpkg::Compression::Process - run compression/decompression processes - perldoc - [phpMan]

## NAME
    [Dpkg::Compression::Process](https://www.chedong.com/phpMan.php/perldoc/Dpkg%3A%3ACompression%3A%3AProcess/markdown) - run compression/decompression processes

## DESCRIPTION
    This module provides an object oriented interface to run and manage compression/decompression
    processes.

## METHODS
    $proc = [Dpkg::Compression::Process](https://www.chedong.com/phpMan.php/perldoc/Dpkg%3A%3ACompression%3A%3AProcess/markdown)->new(%opts)
        Create a new instance of the object. Supported options are "compression" and
        "compression_level" (see corresponding set_* functions).

    $proc->set_compression($comp)
        Select the compression method to use. It errors out if the method is not supported according
        to compression_is_supported() (of [Dpkg::Compression](https://www.chedong.com/phpMan.php/perldoc/Dpkg%3A%3ACompression/markdown)).

    $proc->set_compression_level($level)
        Select the compression level to use. It errors out if the level is not valid according to
        compression_is_valid_level() (of [Dpkg::Compression](https://www.chedong.com/phpMan.php/perldoc/Dpkg%3A%3ACompression/markdown)).

    @exec = $proc->get_compress_cmdline()
    @exec = $proc->get_uncompress_cmdline()
        Returns a list ready to be passed to exec(), its first element is the program name (either
        for compression or decompression) and the following elements are parameters for the program.

        When executed the program acts as a filter between its standard input and its standard
        output.

    $proc->compress(%opts)
        Starts a compressor program. You must indicate where it will read its uncompressed data from
        and where it will write its compressed data to. This is accomplished by passing one
        parameter "to_*" and one parameter "from_*" as accepted by [Dpkg::IPC::spawn](https://www.chedong.com/phpMan.php/perldoc/Dpkg%3A%3AIPC%3A%3Aspawn/markdown)().

        You must call wait_end_process() after having called this method to properly close the
        sub-process (and verify that it exited without error).

    $proc->uncompress(%opts)
        Starts a decompressor program. You must indicate where it will read its compressed data from
        and where it will write its uncompressed data to. This is accomplished by passing one
        parameter "to_*" and one parameter "from_*" as accepted by [Dpkg::IPC::spawn](https://www.chedong.com/phpMan.php/perldoc/Dpkg%3A%3AIPC%3A%3Aspawn/markdown)().

        You must call wait_end_process() after having called this method to properly close the
        sub-process (and verify that it exited without error).

    $proc->wait_end_process(%opts)
        Call [Dpkg::IPC::wait_child](https://www.chedong.com/phpMan.php/perldoc/Dpkg%3A%3AIPC%3A%3Awaitchild/markdown)() to wait until the sub-process has exited and verify its return
        code. Any given option will be forwarded to the wait_child() function. Most notably you can
        use the "nocheck" option to verify the return code yourself instead of letting wait_child()
        do it for you.

## CHANGES
  Version 1.00 (dpkg 1.15.6)
    Mark the module as public.