Curly Brace Group in Linux BASH

ACMer

11 years ago

In Linux BASH shell, you can use curly brace {} to represent a set of possible values in an array. For example,

touch abc{1,2,3,4}

This will be equivalent to four command as follows and as a result, 4 files will be generated.

touch abc1
touch abc2
touch abc3
touch abc4

Please note that there should not be spaces inside the curly braces. For example,

~$ echo abc{1, 2, 3, 4}
abc{1, 2, 3, 4}

However,

~$ echo abc{" 1"," 2"," 3"," 4"}
abc 1 abc 2 abc 3 abc 4

This is useful, if you want to make several folders under a specific directory, you can use this elegant solution:

mkdir /some/dir/{a,b,c,d}

This will create four commands as:

mkdir /some/dir/a
mkdir /some/dir/b
mkdir /some/dir/c
mkdir /some/dir/d