GNU Parallel - Summary

This software is part of the GNU Project.

NAME

parallel - build and execute shell command lines from standard input in parallel

DESCRIPTION

GNU parallel is a shell tool for executing jobs concurrently locally or using remote computers. A job is typically a single command or a small script that has to be run for each of the lines in the input. The typical input is a list of files, a list of hosts, a list of users, a list of URLs, or a list of tables.

If you use xargs today you will find GNU parallel very easy to use as GNU parallel is written to have the same options as xargs. If you write loops in shell, you will find GNU parallel may be able to replace most of the loops and make them run faster by running several jobs simultaneously.

GNU parallel makes sure output from the commands is the same output as you would get had you run the commands sequentially. This makes it possible to use output from GNU parallel as input for other programs.

For each line of input GNU parallel will execute  command  with the line as arguments. If no  command  is given, the line of input is executed. Several lines will be run in parallel. GNU parallel can often be used as a substitute for xargs or cat | bash.

Before looking at the options you may want to check out the examples after the list of options. That will give you an idea of what GNU parallel is capable of.

EXAMPLES

You may want to watch the intro video for a quick introduction: https://www.youtube.com/watch?v=OpaiGYxkSuQ

Go through the tutorial https://www.gnu.org/software/parallel/parallel_tutorial.html or
see the man page or https://www.gnu.org/software/parallel/man.html#EXAMPLE:-Working-as-xargs--n1.-Argument-appending
for more examples.

Registration Date: Mon 27 Aug 2007 02:16:53 PM UTC
License: GNU General Public License v3 or later
Development Status: 5 - Production/Stable