NAME¶

Dpkg::Compression::Process - run compression/decompression processes

DESCRIPTION¶

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

METHODS¶

$proc = Dpkg::Compression::Process->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).

$proc->set_compression_level($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).

@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().

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().

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() 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¶