I picked up this simple modification of the bash .inputrc file a few weeks ago and it has been a great addition to my command line armamentarium. It allows you to perform a case-insensitive search through the bash history (forward or reverse) for anything that you type on the command line with the up and down arrows.
If you don’t already have a .inputrc file, create it in this path
Then, include the following script in the file:
1 2 3 4
Load your bash terminal and now you can perform a case-insensitive search for anything that you enter on the command line in a forward (with the down arrow) or reverse (with the up arrow) direction.