GNU parallel not working at all

gnu, gnu-parallel, parallel-processing, xargs

Solution

As I was about to complete writing this question, I ran `parallel --version` to report the version, only to find:

WARNING: YOU ARE USING --tollef. IF THINGS ARE ACTING WEIRD USE --gnu.

It is not clear to me why that flag is set by default. Needless to say, using `--gnu` worked!

Thought I would post this to save someone hours of frustration and confusion.

EDIT: To fix this permanently (in Ubuntu at least), delete the `--tollef` flag in `/etc/parallel/config`

Problem

I have been trying to use GNU parallel for some time, but I have never been able to get it to function at all! For example, running (in a non-empty directory!): ``` ls | parallel echo # Outputs single new line ls | parallel echo echo echo # Outputs three new lines. ls | parallel echo {} # /bin/bash: {}: command not found ls | parallel echo '{}' # /bin/bash: {}: command not found ls | parallel 'echo {}' # Outputs: {} ls | parallel -IMM 'echo MM' # Outputs: MM ``` It seems that it is simply executing each argument as a command, which makes no sense. I have tried bash, zsh, tcsh, csh, and sh, to no avail.

Original source