21sh/builtins
- 3.1.1 cd
- 3.1.1.1 Options
- 3.1.2 echo
- 3.1.3 env
- 3.1.3.1 Options
- 3.1.4 exit [n]
- 3.1.5 setenv
- 3.1.6 unsetenv
3.1.1 cd
Change the current working directory to directory. If directory is not supplied, the value of the HOME shell variable is used.
3.1.1.1 Options
-L: symbolic links in directory are resolved after cd processes an instance of ‘..’ in directory.
-P: not follow symbolic links: symbolic links are resolved while cd is traversing directory and before processing an instance of ‘..’ in directory.
3.1.2 echo
Outputs it's args to stdout, separated by spaces, followed by a newline. The return status is always 0.
3.1.3 env
Set the environment for command invocation.
3.1.3.1 Options
-i: Invoke utility with exactly the environment specified by the arguments; the inherited environment shall be ignored completely.
3.1.4 exit [n]
Shall cause the shell to exit with the exit status specified by the unsigned decimal integer n.
3.1.5 setenv
Change the value of a shell option and set the positional parameters, or display the names and values of shell variables.
Syntax:
setenv [parameter name] [parameter value]
3.1.6 unsetenv
Remove variable.
Syntax:
unsetenv [parameter name]