How do you send commands with arguments already inside them to GNU parallel?

Question

I have a bash array:

nodes=(
    "command"
    "command arg"
    ...
    )

and I want to run all the commands with all the arguments that are already attached to them using GNU parallel.

I've tried

printf '%s\n' "${nodes[@]}" | parallel python

and

parallel python ::: "${nodes[@]}"

The output command is

python path_to_file\ arg

and the error it gives is "can't open file 'path_to_file arg'"

I think the problem has to do that backslash - I get the same error when I run the command without parallel.

How do I prevent it from putting the backslash in?

Answer 1

Try:

printf '%s\n' "${nodes[@]}" | parallel eval python 

eval is a shell command that evals the string as shell expression. I typically used it to "de-quote" a string.

or:

printf '%s\n' "${nodes[@]}" | parallel python {=uq=}

Newer versions of GNU Parallel have uq() which leaves the value unquoted. Normally GNU Parallel will quote values.

or:

printf '%s\n' "${nodes[@]}" | parallel 

The exception to the rule above is when there is no command. Then the value is unquoted.