Case insensitive comparison of strings in shell script

string shell compare case-insensitive
Sachin Chourasiya picture Sachin Chourasiya · Nov 13, 2009 · Viewed 197.7k times · Source

The == operator is used to compare two strings in shell script. However, I want to compare two strings ignoring case, how can it be done? Is there any standard command for this?

Answer

alphaniner picture alphaniner · Oct 16, 2013

In Bash, you can use parameter expansion to modify a string to all lower-/upper-case:

var1=TesT
var2=tEst

echo ${var1,,} ${var2,,}
echo ${var1^^} ${var2^^}

Related questions

How to check if a string contains a substring in Bash

I have a string in Bash: string="My string" How can I test if it contains another string? if [ $string ?? 'foo' ]; then echo "It's there!" fi Where ?? is my unknown operator. Do I use echo and grep? if echo "$string" | …

Read More
Extract substring in Bash

Given a filename in the form someletters_12345_moreleters.ext, I want to extract the 5 digits and put them into a variable. So to emphasize the point, I have a filename with x number of characters then a five digit sequence …

Read More
How to convert a string to lower case in Bash?

Is there a way in bash to convert a string into a lower case string? For example, if I have: a="Hi all" I want to convert it to: "hi all"

Read More