// run a command repeatedly with input as arguments
command →
upstream (optional) →
Leave blank to show just the xargs invocation. Filled in, the command appears as a pipeline: upstream | xargs …
generated command
$ xargs echo
⚠ This command contains characters that have special meaning in the shell (such as $, `, ;, |, &). Review the command carefully before pasting into a terminal.
// xargscraft — xargs reference
xargs reads items from standard input (separated by whitespace by default) and runs a command, passing the items as arguments. The classic companion to find, but also useful with ls, grep, cat, or any pipeline that produces a list.
upstream | xargs [options] command [initial-args]
the spaces-in-filenames problem
By default xargs splits input on any whitespace (spaces, tabs, newlines), and quotes are stripped. This breaks for filenames with spaces.
The standard fix: use find ... -print0 together with xargs -0 so items are separated by NUL bytes (which can't appear in filenames):
find . -name "*.tmp" -print0 | xargs -0 rm
positioning input with -I
By default, xargs appends input items to the end of the command. Use -I {} to place the input wherever you want:
default
... | xargs mv -t /dest/ — items go at the end
-I {}
... | xargs -I {} mv {} /dest/{}.bak — items go where {} appears
With -I, xargs runs the command once per item, not in batches.
parallelism with -P
-P N runs up to N processes at once. -P 0 means "as many as possible (no limit)". Pair with -n to control how many items each process gets:
• Always pair -print0 with -0 when piping from find. This is the only safe way to handle arbitrary filenames.
• Use -r (or --no-run-if-empty) to avoid running the command at all when the input is empty. GNU xargs only; not in POSIX.
• Test runs with -t (trace, prints the command before running it) or -p (prompt before each).
• xargs -L 1 runs the command once per line of input (instead of per whitespace-separated token).
• If the command has its own arguments that should always be present, put them right after the command name: xargs rm -rf applies -rf to every batch.
safety & disclaimer
This is an educational tool. The commands it builds are real — they will do exactly what you tell them to. Some flags are destructive (deletion, overwriting, forced operations) and even non-destructive options can cause data loss or system trouble in the wrong circumstances.
• Always review the generated command before running it.
• Test on disposable files and directories first.
• If you do not understand what a flag does, look it up in the official manual page (man command).
The author of these pages is not responsible for any damage, data loss, or other consequences resulting from commands generated, copied, or run from this site. Use at your own risk.
