How does the -n option work in xargs when used with -P option?

The -n option in xargs specifies the maximum number of arguments that can be passed to the command for each invocation. When used in conjunction with the -P option, which allows for parallel execution of commands, -n controls how many arguments are sent to each instance of the command that is run in parallel.

Example:

echo "one two three four five" | xargs -n 2 -P 2 echo

In this example:

• -n 2 means that xargs will pass 2 arguments to each echo command.
• -P 2 allows up to 2 instances of echo to run in parallel.

The output might look like this:

one two
three four
five

Here, xargs creates two processes that each handle two arguments at a time, and the last argument (five) may be handled by one of the existing processes or a new one, depending on how many processes are still running.