Help for shell builtins

If you play around enough with man pages, you may notice that a lot of shell builtin commands do not have a man page. For instance, there is no man page for the cd or the exit commands:

elliot@ubuntu-linux:~$ type cd 
cd is a shell builtin 
elliot@ubuntu-linux:~$ man cd 
No manual entry for cd 
elliot@ubuntu-linux:~$ type exit 
exit is a shell builtin 
elliot@ubuntu-linux:~$ man exit 
No manual entry for exit

That's because shell builtin commands do not have man pages, but do not freak out just yet! You can still find help on how to use shell builtins by using the help command. For example, to get help on how to use the exit command, you can run:

elliot@ubuntu-linux:~$ help exit 
exit: exit [n]
    Exit the shell.

    Exits the shell with a status of N. If N is omitted, the exit status 
    is that of the last command executed.

Similarly, to get help on how to use the cd command, you can run the help cd command:

elliot@ubuntu-linux:~$ help cd 
cd: cd [-L|-P] [dir]
    Change the shell working directory.

    Change the current directory to DIR. The default DIR is the value of 
    the HOME shell variable.

    The variable CDPATH defines the search path for the directory containing DIR.  
    Alternative directory names in CDPATH are separated by a colon (:). 
    A null directory name is the same as the current directory. 
    If DIR begins with a slash (/), then CDPATH is not used.

    If the directory is not found, and the shell option `cdable_vars' is set, 
    the word is assumed to be a variable name. If that variable has a value, 
    its value is used for DIR.

    Options:
        -L force symbolic links to be followed
        -P use the physical directory structure without following symbolic links
    The default is to follow symbolic links, as if `-L' were specified. 

    Exit Status:
    Returns 0 if the directory is changed; non-zero otherwise.