Use gzip to compress the files in a directory except for already existing .gz files

gzip

I have a directory of logs that I would like to set up a job to compress using gzip. The issue is I don't want to recompress the logs I've already compressed.

I tried using ls | grep -v gz | gzip, but that doesn't seem to work.

Is there a way to do this? Basically I want to gzip every file in the directory that does not end in .gz.

Best Answer

You can just do:

gzip *

gzip will tell you it skips the files that already have a .gz ending.
If that message gets in the way you can use:

gzip -q *

What you tried did not work, because gzip doesn't read the filenames of the files to compress from stdin, for that to work you would have to use:

ls | grep -v gz | xargs gzip

You will exclude files with the pattern gz anywhere in the file name, not just at the end.¹ You also have to take note that parsing the output of ls is dangerous when you have file names with spaces, newlines, etc., are involved.

A more clean solution, not relying on gzip to skip files with a .gz ending is, that also handles non-compressed files in subdirectories:

find .  -type f ! -name "*.gz" -exec gzip {} \;


¹ As izkata commented: using .gz alone to improve this, would not work. You would need to use grep -vF .gz or grep -v '\.gz$'. That still leaves the danger of processing ls' output

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