Grep-ing gzipped files

Question

I have a set of 100 log files, compressed using gzip. I need to find all lines matching a given expression. I'd use grep, but of course, that's a bit of a nightmare because I'll have to unzip all files, one by one, grep them and delete the unzipped version, because they wouldn't all fit on my sevrer if they were all unzipped.

Anyone has a little trick on how to get that done quickly?

score 25 · Accepted Answer · edited Oct 21 '13 at 14:05

25

You might have a look at zgrep.

>$ zgrep -h
grep through gzip files
usage: zgrep [grep_options] pattern [files]

edited Oct 21 '13 at 14:05

mveroone

484

answered Oct 21 '13 at 13:53

Francois Wolmarans

1,600

score 10 · Answer 2 · answered Oct 21 '13 at 13:54

10

The zgrep program exists for this specific purpose.

http://linux.about.com/library/cmd/blcmdl1_zgrep.htm

answered Oct 21 '13 at 13:54

Emyl

380
2
11

score 4 · Answer 3 · answered Oct 21 '13 at 14:10

4

Or, if your OS doesn't come with zgrep, something like this.

gunzip -c somefile1.gz [...] | grep 'string'

answered Oct 21 '13 at 14:10

USD Matt

5,411
18
26

Boscoe · Answer 4 · 2013-10-21T20:45:44.040

3

There's a utility called zcat, which is a version of cat that works on gzipped files. In your situation, you could do something like the following:

zcat yourfile.gz | grep 'serverfault is awesome'

edited Oct 21 '13 at 20:45

answered Oct 21 '13 at 14:35

Boscoe

574

score 1 · Answer 5 · answered Oct 21 '13 at 14:14

While zgrep appears to be the next best thing since sliced bread, I thought I'd post an alternative...

You can use piping to unzip the log files before grepping them, without taking up disk space. For example:

cat /var/log/program.log.*.gz | gunzip | grep 'stuff and things'

Grep-ing gzipped files

5 Answers5