How can I pass all arguments with xargs in middle of command in linux

Question

I want to pass all the files as a single argument on Linux but I am not able to do that.

This is working

ls | sort -n | xargs  -i pdftk  {} cat output combinewd2.pdf

This passes a single argument per command, but I want all in one command.

Answer 1

Use -I option:

echo prefix | xargs -I % echo % post

Output:

prefix post