Bash - check if string contains substring

In this article, we would like to show you how to check if string contains substring in Bash.

1. Using Wildcards

The simplest way to check if a string contains given substring is by using Bash wildcards.

#!/bin/bash

string='Example text...'
substring='text'

if [[ "$string" == *"$substring"* ]]; then
    echo "The string contains the substring."
fi

Run in command line:

./script.sh

Output:

The string contains the substring.

2. Using Regex

Another simple solution is to use regex operator (=~).

#!/bin/bash

string='Example text...'
substring='text'

if [[ "$string" =~ .*"$substring".* ]]; then
    echo "The string contains the substring."
fi

Run in command line:

./script.sh

Output:

The string contains the substring.