How to use GNU parallel with gunzip

Question

I have a directory full of .gz, I want to expand each archive in parallel with GNU parallel. However I did not achieve anything.

I tried

parallel 'gunzip {}' ::: `ls *.gz`
parallel gunzip `ls *.gz`

with no results, bash tells me:

/bin/bash: archive1.gz: command not found
...

What am I doing wrong?

Thanks

Answer 1

I found this, which suggests using the --gnu flag:

parallel --gnu gunzip  ::: *gz

If this works, you should either delete /etc/parallel/config or change its contents to --gnu rather than --tollef (as root):

echo "--gnu" > /etc/parallel/config

Also, never parse the output of ls., use globbing as I have above or find instead:

find . -name "*gz*" -print0 | parallel -q0 gunzip 

Answer 2

Doing this works:

   ls *.gz | parallel -t gunzip

The -t is optional but is useful as it shows you the commands that are executed on stderr.

I'm not sure you are doing anything wrong ::: should work (it's meant to be equivalent) but not even the examples in the man page work for me.

Update: the --gnu flag makes it work as terdon said.