Mastering xargs: Powerful Linux Command‑Line Tricks Explained

When combined with other commands, the xargs utility becomes extremely useful. This tutorial explains its usage through several simple examples.

xargs [-0prtx] [-E eof-str] [-e[eof-str]] [--eof[=eof-str]] [--null] [-d delimiter] [--delimiter delimiter] [-I replace-str] [-i[replace-str]] [--replace[=replace-str]] [-l[max-lines]] [-L max-lines] [--max-lines[=max-lines]] [-n max-args] [--max-args=max-args] [-s max-chars] [--max-chars=max-chars] [-P max-procs] [--max-procs=max-procs] [--interactive] [--verbose] [--exit] [--no-run-if-empty] [--arg-file=file] [--show-limits] [--version] [--help] [command [initial-arguments]]

1. Basic xargs example

The xargs command reads from standard input and, by default, runs /bin/echo on the input.

$ xargs
Hi,
Welcome to TGS.

After typing the input and pressing Ctrl+D , the string is echoed back:

$ xargs
Hi,
Welcome to TGS.
Hi, Welcome to TGS.

2. Using the -d option to specify a delimiter

The -d option lets you treat each character literally as a delimiter. Using -d\n preserves newline characters in the output.

$ xargs -d

Hi,
Welcome to TGS.
Hi,
Welcome to TGS.

3. Limiting output lines with -n

The -n option splits the output into multiple lines, showing a specified number of items per line.

$ echo a b c d e f | xargs -n 3
a b c
d e f

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

4. Prompting the user before execution with -p

The -p option asks for confirmation before running each command.

$ echo a b c d e f | xargs -p -n 3
/bin/echo a b c ?
/bin/echo d e f ?
y
d e f

Answering “n” prevents execution.

5. Avoiding default /bin/echo on empty input with -r

When there is no input, xargs normally runs /bin/echo. Using -r suppresses this behavior.

$ xargs -r

6. Printing the command and its output with -t

The -t option displays the command that xargs executes before showing the output.

$ xargs -t
A B C D
/bin/echo A B C D
A B C D

7. Combining xargs with find

This is one of the most important uses: feed the list of files from find into xargs to run another command, such as rm -rf.

$ ls
one.c  one.h  two.c  two.h
$ find . -name "*.c" | xargs rm -rf
$ ls
one.h  two.h

8. Deleting files with spaces in their names

Files whose names contain spaces are not removed by the simple find | xargs rm pipeline. Using -print0 with find and -0 with xargs handles such names correctly.

$ touch "The Geek Stuff.c"
$ find . -name "*.c" -print0 | xargs -0 rm -rf
$ ls
one.h  two.h

9. Showing system limits with --show-limits

$ xargs --show-limits
Your environment variables take up 1203 bytes
POSIX upper limit on argument length: 2093901
POSIX smallest allowable upper limit on argument length: 4096
Maximum length of command we could actually use: 2092698
Size of command buffer we are actually using: 131072

10. Combining xargs with grep

Use xargs to pass the list of files from find to grep for pattern searching.

$ find . -name '*.c' | xargs grep 'stdlib.h'
./tgsthreads.c:#include
./valgrind.c:#include
./direntry.c:#include
./xvirus.c:#include
./temp.c:#include