Shell Builtin Commands

The set of portable commands.

Contents

Commands

Command	Description	Example
`.`
`:`	No-op
`alias`	Creates an alias
`bind`
`builtin`	Executes a builtin command
`cd`	Changes the current working directory
`command`	Executes a command
`dirs`
`disown`
`echo`
`enable`
`eval`	Executes a command
`exec`	Replaces the shell with a command
`exit`	Causes a script or shell to exit immediately
`export`	Marks one or more names as variables to be included in the environment of subsequently-called commands	`export varname="some value"`
`fc`
`getopts`
`hash`
`help`	Prints helpful information about a builtin command
`history`
`kill`
`logout`	Exits a login shell immediately
`mapfile`
`popd`
`printf`
`pushd`
`pwd`	Prints the current working directory
`read`
`readarray`
`readonly`
`set`	Sets a shell option
`shift`	Renames the positional variables
`test`	Executes a test
`time`
`trap`	Creates a trap
`typeset`
`unalias`	Removes an alias
`unset`	Unsets a shell option
`wait`

builtin can be useful to call a builtin command when there is a custom command with the same name.

Calling cd without an argument is the same as cd ~.

cd - changes the current working directory to the previous working directory.

command can be useful to call a command when there is a function with the same name.

command is also commonly used to determine if a command is locally available.

if ! command -v mypy >/dev/null 2>&1; then
  echo "cannot locate mypy; is it installed?"
  exit
fi

Some parts of the language are technically implemented as a command.

See here for break and continue.

See here for return.

See here for bg, fg, and jobs.