How to make xargs append trailing arguments with -n?

Question

xargs is good at inserting initial arguments:

seq 0 10 | xargs -n 3 echo foo

produces this output:

foo 0 1 2
foo 3 4 5
foo 6 7 8
foo 9 10

What about when I also want trailing arguments? That is, what command:

seq 0 10 | xargs -n 3 <WHAT GOES HERE?>

will produce the following desired output:

foo 0 1 2 bar
foo 3 4 5 bar
foo 6 7 8 bar
foo 9 10 bar

I tried the following:

seq 0 10 | xargs -n 3 -I {} echo foo {} bar

which is almost right, except that it apparently forces 1 item per command line, which isn't what I want:

foo 0 bar
foo 1 bar
foo 2 bar
foo 3 bar
foo 4 bar
foo 5 bar
foo 6 bar
foo 7 bar
foo 8 bar
foo 9 bar
foo 10 bar

Answer 1

After figuring this out with a head-start from @netniV's answer, I now see that the man page actually contains an example showing how to do it:

xargs sh -c 'emacs "$@" < /dev/tty' emacs

Launches the minimum number of copies of Emacs needed, one after the other, to edit the files listed on xargs' standard input. This example achieves the same effect as BSD's -o option, but in a more flexible and portable way.

And the wikipedia page shows a similar technique, with an explanation of the dummy arg at the end:

Another way to achieve a similar effect is to use a shell as the launched command, and deal with the complexity in that shell, for example:

$ mkdir ~/backups
$ find /path -type f -name '*~' -print0 | xargs -0 bash -c 'for filename; do cp -a "$filename" ~/backups; done' bash

The word bash at the end of the line is interpreted by bash -c as special parameter $0. If the word bash weren't present, the name of the first matched file would be assigned to $0 and the file wouldn't be copied to ~/backups. Any word can be used instead of bash, but since $0 usually expands to the name of the shell or shell script being executed, bash is a good choice.

So, here's how to do it:

seq 0 10 | xargs -n 3 sh -c 'echo foo "$@" bar' some_dummy_string

The output is as desired:

foo 0 1 2 bar
foo 3 4 5 bar
foo 6 7 8 bar
foo 9 10 bar