09.12.2017

The Advent of Void: Day 9: zutils

We often deal with compressed files, and these days there quite a few popular formats, e.g. gzip, bzip2, and xz.

When we deal with mixed formats, standard tools quickly get messy:

% date | gzip > date.gz
% date | bzip2 > date.bz2   
% date | xz > date.xz      
% zcat date.*

gzip: date.bz2: not in gzip format
Sat Dec  9 18:37:12 CET 2017

gzip: date.xz: not in gzip format
% xzcat date.* 
xzcat: date.bz2: File format not recognized
xzcat: date.gz: File format not recognized
Sat Dec  9 18:37:24 CET 2017
% bzcat date.* 
Sat Dec  9 18:37:20 CET 2017
bzcat: date.gz is not a bzip2 file.
bzcat: date.xz is not a bzip2 file.

Luckily, there are the zutils, which provide some compression-aware general purpose Unix tools. In Void Linux, they use a capital Z as command prefix, to avoid name clashes.

Zcat(1) will decompress all supported file formats on the fly:

% Zcat date.*
Sat Dec  9 18:37:20 CET 2017
Sat Dec  9 18:37:12 CET 2017
Sat Dec  9 18:37:24 CET 2017

Very useful is Zgrep(1) to search in compressed files:

% Zgrep :2. date.*
date.bz2:Sat Dec  9 18:37:20 CET 2017
date.xz:Sat Dec  9 18:37:24 CET 2017

In contrast to the zgrep(1) script of gzip, it supports the -r flag to recurse into directories, which is very useful if you want to search in all files in /var/log for example.

zutils also contains Zcmp(1) and Zdiff(1) to compare files to each other, and Ztest to verify files are not corrupted.