Searching your command history on macOS terminal

Use Ctrl + R for searching a command from history in Terminal.

(reverse-i-search)`': 

Type any substring of the command you want to search e.g. grep

(reverse-i-search)`grep': grep "XYZ" abc.txt

It will return the latest command that matches your input. If that is not the command you were searching for, keep pressing Ctrl + R for next match until you find your command.

Once you found your command press Return to execute it.

If you want to exit without running any command, press Ctrl + G

PS: This answer is same as suggested by Inian, just giving more details for easy usage.

The command history is stored under your home folder in a hidden file called .bash_history. To view it's content in nano, use the following command in Terminal:

nano ~/.bash_history

Or open with your text editor (default is TextEdit):

open ~/.bash_history

In my case it's a very long list and as I scroll through seems like the last ~500 command is stored here.

How about using Ctrl+R for searching on the Terminal Utility in Mac for searching on the command history,

dudeOnMac: freddy$ whoami
freddy
(reverse-i-search)`who': whoami

Well for controlling how long the history would be retained that depends on a few shell environment variables, HISTFILESIZE which is nothing but number of lines of history you want to retain. Set a huge value for it in .bash_profile for it to take effect

HISTFILESIZE=10000000 

Migrating an answer to SO from this answer on the Unix and Linux Stack Exchange:

Pressing ctrl+R will open the history-search-backward. Now start typing your command, this will give the first match. By pressing ctrl+R again (and again) you can cycle through the history.

If you like to be super lazy you can bind the up/down arrow keys to perform this search, I have the following in my .inputrc to bind the up/down arrow key to history-search-backward and history-search-forward:

# Key bindings, up/down arrow searches through history
"\e[A": history-search-backward
"\e[B": history-search-forward
"\eOA": history-search-backward
"\eOB": history-search-forward

Just type something (optional), then press up/down arrow key to search through history for commands that begin with what you typed.

To do this in .bashrc rather than .inputrc, you can use:

bind '"\e[A": history-search-backward'