Question

GNU xargs has option ‘-x’. The man page says:

-x Exit if the size (see the -s option) is exceeded.

But xargs seems to not care if -x is set or not. I have been unable to make an example in which the -x has any effect at all.

Please provide two examples in which the only difference is an added -x and that produce different output.

Answer 1

You have to set a size to test whether you’ve exceeded it.

$ echo -e "12\n1234"
12
1234
$ echo -e "12\n1234" | xargs echo
12 1234
$ echo -e "12\n1234" | xargs  -x echo        # no effect
12 1234
$ echo -e "12\n1234\n13" | xargs -s 8 echo   # process valid args until an error occurs
xargs: argument line too long
12
$ echo -e "12\n1234" | xargs -s 8 -x echo    # error and exit
xargs: argument line too long