Bash xargs Command - Build Commands from Input

Using the xargs Command

Some commands, like rm, touch and echo, do not read from a pipe. They need their arguments on the command line.

The xargs command solves this. It reads items from its input and adds them as arguments to another command.

The examples below use this file, names.txt:

Liam
Emma
Noah

Basic Usage

Here, xargs reads the three names and runs echo once with all of them:

cat names.txt | xargs echo Hello
Hello Liam Emma Noah

This is the same as typing echo Hello Liam Emma Noah.

One Item at a Time (-n)

Use -n 1 to run the command once for each item:

cat names.txt | xargs -n 1 echo Hello
Hello Liam
Hello Emma
Hello Noah

Place the Item Anywhere (-I)

Use -I {} to choose where the item goes in the command. Every {} is replaced by the item:

cat names.txt | xargs -I {} touch {}.txt
ls Liam.txt Emma.txt Noah.txt
Emma.txt  Liam.txt  Noah.txt

Use xargs with find

find and xargs are often used together. This counts the lines of every .sh file in the project folder:

find project -name "*.sh" | xargs wc -l
 1 project/scripts/test.sh
 1 project/scripts/build.sh
 2 total

If file names can contain spaces, use find -print0 with xargs -0. The names are then separated by a special null character instead of spaces:

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

Ask Before Running (-p)

Use -p to make xargs show each command and ask before running it. Type y to run it:

cat names.txt | xargs -p -n 1 echo
echo Liam?...y
Liam