[Help-bash] Bash history

[Bharath Bhushan Lohray]

Hi,

I would like to modify the way bash retrieves history at the command
prompt. What source file do I find this part of the code?

I would like to restrict the history retrieval to only the commands that
begin with the letters at the prompt.

For example -
$ l
<up arrow>
$ ls
<up arrow>
$ ls -alh
<up arrow>
$ ls -lh /var/log

I may also like to add a modifier to this - like use <shift> + <up arrow>
to trigger this behaviour.

Any tips would be helpful.

Warm regards,
Bharath.