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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.
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