How to get the first n characters of a string in Bash

In this tutorial, we are going to learn about how to get the first n characters of a string in Bash.

Consider, we have the following string.

country="portugal"

Now, we want to get the first 3 characters por from the above string.

Getting the first n characters

To access the first n characters of a string, we can use the (substring) parameter expansion syntax ${str:position:length} in the Bash shell.

position: The starting position of a string extraction.

length: The number of characters we need to extract from a string.

Here is an example that gets the first 3 characters from the following string:

country="portugal"
firstThree=${country:0:3}

echo $firstThree

Output:

"por"

This above syntax can also be written like this:

country="portugal"
firstFour=${country::3}

echo $firstThree # "por"

Similarly, you can also get the first 4 characters of a string like this:

country="portugal"
firstFour=${country::4}

echo $firstFour # "port"