Bash for loop is popular programming structure used by a lot of Linux system administrators. For loops can be used in a lot of different cases. We have all ready examined the bash while and for loop in the following tutorial.
Bash For and While Loop Examples
In this tutorial we will look more specific topic named for loop with range
Specify Range with Numbers
Linux bash provides mechanism to specify range with numbers. We will use {FIRST..LAST}
. We need to specify the start and end numbers where the range will be incremented one by one by default. In this example we will use range from 1 to 10 .
$ for i in {1..10}; do echo $i; done

Specify Range with Numbers By Specifying Increment Value
In previous example we have incremented the range one by one by default. But in some situations we may need to increment numbers different than one. We will use {FIRST..LAST..INCREMENT}
. We will start from 1 to the 10 and increment 2 in this example.
$ for i in {1..10..2}; do echo $i; done

Specify Range with Seq Command
seq
is a command or tool used in bash which provides sequential data or numbers. Syntax is like below.
seq FIRST LAST
We will set first 1 and last as 10 in this example.
$ for i in $(seq 1 10); do echo $i; done

Specify Range with Seq Command By Specifying Increment Value
seq
command can be also used to specify different increment value than 1 . The seq
command with different increment value is like below.
seq FIRST INCREMENT LAST
In this example we will start from 1 and increment with 2 up to 10
$ for i in $(seq 1 2 10); do echo $i; done
