Bash - check if string is not equal to

In this article, we would like to show you how to check if check if string is not equal to another string in Bash.

In this example, we use == operator to check if string is not equal to another string inside the if statement.

script.sh file:

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#!/bin/bash

​

string="abc"

​

if [ "$string" != "test" ]; then

    echo "The strings are not equal"

fi

Note: this approach should be used in POSIX shells where other solutions may not work.

Run in command line:

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./script.sh

Output:

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The strings are not equal

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#!/bin/bash

​

string="abc"

​

if test "$string" != "test"; then

    echo "The strings are not equal"

fi

Note: [ ] notation is shorthand of test command.

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#!/bin/bash

​

string="abc"

​

if [[ "$string" != "test" ]]; then

    echo "The strings are not equal"

fi

Note: [[ ]] notation is like extended test command, adding additional features (e.g. regular expressions).

1. Bash - check if string is equal to

2. Bash - check if string is less than (ASCII alphabetical order)

3. Bash - check if string is greater than (ASCII alphabetical order)