How to convert filenames or text to lowercase on the Linux command line

There is no simple 'tolower' command on the bash, but you can convert uppercase characters to lowercase with a little shell script. The script uses the tr command internally for converting the chars.

Create a shell script with the name 'tolower' that converts all text that is given as a command-line argument to lower case:

nano /usr/local/bin/tolower

and enter the following content:

#!/bin/sh
echo $1 | tr '[:upper:]' '[:lower:]'

Then make the script executable:

chmod +x /usr/local/bin/tolower

An test it by executing this command on the shell:

tolower "Thats a Test"

will convert the string to lowercase and show the result on the shell:

thats a test

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