You probably know command substitution. Command substitution executes a command and uses its output as a variable on the shell. The operator for this is either the backtick operator. But did you also know that there is a counterpart of command substitution? This counterpart is called process substitution.
You probably know the bash history function. All commands you entered are stored in memory and will be written to
~/.bash_history as soon as you exit your current shell. You may have used this often by tapping the up and down arrow keys to repeat the last few commands. But did you know that bash can do much more history work for you?