As you've seen throughout this book, the bash shell contains lots of features and thus has lots of commands available. This appendix provides a concise guide to allow you to quickly look up a feature or command that you can use from the bash command line or from a bash shell script.
The bash shell includes many popular commands built into the shell. This provides for faster processing times when using these commands. Table A-1 shows the built-in commands available directly from the bash shell.
The built-in commands provide higher performance than external commands, but the more built-in commands that are added to a shell, the more memory it consumes with commands that you may never use. The bash shell also contains external commands that provide extended functionality for the shell. These are discussed in the next section.
Besides the built-in commands, the bash shell utilizes external commands to allow you to maneuver around the filesystem and manipulate files and directories. Table A-2 shows the common external commands you'll want to use when working in the bash shell.
You can accomplish just about any task you need to on the command line using these commands.
Table A.1. bash Built-in Commands
Define an alias for the specified command.
Resume a job in background mode.
Bind a keyboard sequence to a readline function or macro.
Exit from a