Bash - trim string

In this article, we would like to show you how to trim string using Bash.

Quick solution:

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echo '   text   ' | awk 'match($0,/^\s*(.*)\s*$/,g){print g[1]}'

Note:

On the internet you can also find a solution using xargs, however it was not created to trim text and may damage your code.

In this example, we create a reusable function that uses awk to trim the string that we pass as the first argument ($1).

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#!/bin/bash

​

function trim_string() {

    echo "$1" | awk 'match($0,/^\s*(.*)\s*$/,g){print g[1]}'

}

​

​

# Usage example 1:

​

trim_string '   text   '

In this example, we present a script that uses Bash wildcards to trim whitespace characters from the variable string.

script.sh file:

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#!/bin/bash

​

variable="     text  "

​

# removes spaces from the beginning

variable="${variable#"${variable%%[![:space:]]*}"}"

​

# removes spaces from the end

variable="${variable%"${variable##*[![:space:]]}"}"   

​

echo "$variable"

Run in command line:

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./script.sh

Output:

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text