xargs flags & options

-I

Replace a placeholder string with each input line. Commonly uses {}.

find . -name "*.bak" | xargs -I {} mv {} {}.old

cat urls.txt | xargs -I {} curl -s {}

-n

Use at most N arguments per command invocation.

echo "a b c d e f" | xargs -n 2

-P

Run up to N commands in parallel.

cat urls.txt | xargs -P 4 -I {} curl -s {}

-0, --null

Input items are separated by null character instead of whitespace. Pairs with find -print0.

find . -name "*.tmp" -print0 | xargs -0 rm

-t, --verbose

Print each command before executing it.

echo "a b c" | xargs -t echo

-p, --interactive

Prompt before executing each command.

find . -name "*.log" | xargs -p rm

-r, --no-run-if-empty

Don't run the command if stdin is empty. Default on GNU, needed on BSD.

echo "" | xargs -r echo "not empty"

-L

Use at most N input lines per command invocation.

cat hosts.txt | xargs -L 1 ssh -o ConnectTimeout=2