Linux Shells by Example

9.13. Shell Built-In Commands

The shell has a number of commands that are built-in to its source code. Because the commands are built-in, the shell doesn't have to locate them on disk, making execution much faster. The help feature provided with bash give you online help for any built-in command. The built-in commands are listed in Table 9.12 on page 481.

Table 9.12. Built-In Commands

Command	What It Does
:	Do-nothing command; returns exit status zero.
. file	The dot command reads and executes command from file.
break [n]	See the looping commands on page 443.
:	Do-nothing command; returns 0 exit status.
.	Executes program in context of current process; same as source.
alias	Lists and creates "nicknames" for existing commands.
bg	Puts a job in the background. ...