XZ

Synopsis

HELP:   XZ (LZMA) data compression technique
TYPE:   OBJECT
SYNTAX: XZ(LEVEL=num/FAST/LEV0/LEV1/LEV2/LEV3/LEV4/LEV5/LEV6/LEV7/LEV8/LEV9/BEST/AUTO)

Description

The XZ compression conforms to the XZ-compression tool on UNIX-systems. The compression level can be set to values from 0 to 9 (0=fastest, 9=best).

The default level is 6 when no level is specified.

Decompression of concatenated XZ files is also possible. All concatenated files are decompressed into one file. It is also possible to decompress one specific member of this concatenation by specifying the member index of the file to be decompressed:

 filename/:memberindex

If XZ compression is used with write.record(), the file attributes cannot be stored in the XZ file. The record attributes can be added in front of the record (PRNCTR=RETAIN). By default, a 4 byte length field in little endian is written in front of the data. Such an XZ file can be used on record-oriented platforms to recreate the original datasets as PS-VB. You may want to use a ZIP archive or ARMOR encoding to store the file attributes (DCB) to recreate the correct record format and length.

Arguments