Extract Method

Extracts the compressed file from the gzip archive.

Syntax

gzip.extract([callback])

Callback

The 'callback' parameter specifies a function which will be called when the operation completes (or an error is encountered). If the 'callback' parameter is not specified, then the method will block and will not return until the operation completes (or an error is encountered).

The callback for this method is defined as:

function(err){ }

'err' is the error that occurred. If there was no error, then 'err' is 'null'.

'err' has 2 properties which hold detailed information:

err.code
err.message

Remarks

Invoking Extract decompresses the archive specified by ArchiveFile. The compressed file will be extracted, and written to disk. Also, FileCompressedName will be set to the filename found in the archive.

If FileDecompressedName is set to a nonempty string the file will be written there. Otherwise the class will automatically set FileDecompressedName to an appropriate value:

If a filename (i.e., FileCompressedName) is stored in the gzip headers, this filename will be used.

Otherwise, if ArchiveFile ends in ".gz", this filename, less the ".gz" extension will be used. If there are multiple files in the archive, the current 0-based file index will be appended to all files after the first file to differentiate between multiple files. For instance "test.gz" would become "test" for the first file and "test.gz" would become "test.1" for the second file in the archive.

If neither of these two conditions holds, ".unzipped" will be appended to ArchiveFile.