xargs issues commands with the STDIN as arguments, by default appended to the end of the command.

Examples

Get the type of each listing from ls

ls | xargs file

Handle spaces and use the arg as something other than the last token

The -I argument takes a string to use as a delimiter for any input.

ls | xargs -I {} mv "{}" ~/some/dir/

Pass 5 args to each echo command, and never do more than 3 echo processes at a time

echo {1..100} | xargs -n5 -P3 echo

use sed to change git files containing a certain string

This uses GNU sed -i, on macOS you should use sed -i '' or gsed -i.

git grep -l 192.168.5 | xargs sed -i 's/192.168.5/172.18.0/'

Issue the same command several times in parallel

This takes 1 directory as input and starts a sub-shell that cd's to the directory and runs a command. Up to 4 subhells are run in parallel. This is very similar to the GNU parallel command.

find ~/code/ -mindepth 1 -maxdepth 1 -type d |
xargs -I {} -n1 -P4 bash -c "cd {} ; make install-hooks ;"