Bash aliases are essential for anyone using the command line. An alias is basically just a shortcut for some other, typically longer command.
It's nice to have quick access to your command history on the command line, but sometimes it's valuable to know exactly when you typed a command.
As a developer, I've customized my bash prompt to always show the current git branch if I'm in an initialized git repository. This is convenient, but it can make for a very long bash prompt.
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