GNU Parallel usage

GNU Parallel gives you an easy way to run things in parallel.

Basic usage:

parallel $cmd ::: $args

• $args is a list of arguments. ::: means arguments on command line are input source, :::: means arguments are read from file passed on command line.
• in a file, an argument is a full line
• $cmd can contain expansions denoting the input line: {} for filename, {.} for filename without extension, {/} for basename (no path), {#} for job number.
• if there’s no $cmd, the $args are the commands to run in parallel.
• control the number of jobs with -j. default runs one job per CPU thread.