unpack200 - JAR Unpacking tool


unpack200 [ options ] input-file JAR-file

Options may be in any order. The last option on the command line supersedes all previously specified options.

Name of the input file, which can be a pack200 gzip file or a pack200 file. The input could also be JAR file produced by pack200(1) with an effort of 0. In this case the contents of the input file will be copied to the output JAR file with the Pack200 marker.
Name of the output JAR file.


unpack200 is a native implementation that transforms a packed file produced by pack200(1) into a JAR file. Typical usage:

% unpack200 myarchive.pack.gz myarchive.jar

In this example, the myarchive.jar is produced from myarchive.pack.gz using the default unpack200 settings.


Standard Options

-Hvalue --deflate-hint=value

Sets the deflation to be true, false, or keep on all entries within a JAR file. The default mode is keep. If true or false, overrides the default behavior and sets the deflation mode on all entries within the output JAR file.

Non-Standard Options

-r --remove-pack-file

Removes the input packed file.

-v --verbose

Outputs minimal messages. Multiple specification of this option will output more verbose messages.

-q --quiet

Specifies quiet operation with no messages.

-lfilename --log-file=filename

Specifies a log file to output messages.


The following exit values are returned:

 0 if successful completion;

>0 if an error occurred.



This command should not be confused with unpack(1). They are distinctly separate products.

The J2SE API Specification provided with the SDK is the superseding authority, in case of discrepancies.