(features.info)Bourne Shell Builtins

Bourne Shell Builtins
=====================

   The following shell builtin commands are inherited from the Bourne
shell.  These commands are implemented as specified by the Posix 1003.2
standard.

`:'
     Do nothing beyond expanding any arguments and performing
     redirections.

`.'
     Read and execute commands from the FILENAME argument in the
     current shell context.

`break'
     Exit from a `for', `while', or `until' loop.

`cd'
     Change the current working directory.

`continue'
     Resume the next iteration of an enclosing `for', `while', or
     `until' loop.

`echo'
     Print the arguments, separated by spaces, to the standard output.

`eval'
     The arguments are concatenated together into a single command,
     which is then read and executed.

`exec'
     If a COMMAND argument is supplied, it replaces the shell.  If no
     COMMAND is specified, redirections may be used to affect the
     current shell environment.

`exit'
     Exit the shell.

`export'
     Mark the arguments as variables to be passed to child processes in
     the environment.

`getopts'
     Parse options to shell scripts or functions.

`hash'
     Remember the full pathnames of commands specified as arguments, so
     they need not be searched for on subsequent invocations.

`kill'
     Send a signal to a process.

`pwd'
     Print the current working directory.

`read'
     Read a line from the shell input and use it to set the values of
     specified variables.

`readonly'
     Mark variables as unchangable.

`return'
     Cause a shell function to exit with a specified value.

`shift'
     Shift positional parameters to the left.

`test'
`['
     Evaluate a conditional expression.

`times'
     Print out the user and system times used by the shell and its
     children.

`trap'
     Specify commands to be executed when the shell receives signals.

`umask'
     Set the shell process's file creation mask.

`unset'
     Cause shell variables to disappear.

`wait'
     Wait until child processes exit and report their exit status.