Costello calls Abbott with some questions about UNIX:  

Costello:   What is the command that will tell me the revision code of a
            program ?

Abbott:     Yes, that's correct.

Costello:   No, what is it ?

Abbott:     Yes.

Costello:   So, which is the one ?

Abbott:     No. 'which' is used to find the program.

Costello:   Stop this. Who are you ?

Abbott:     Use 'who am i' not 'who r yoo'.
            You can also 'finger yoo' to get information about yoo'.

Costello:   All I want to know is what finds the revision code ?

Abbott:     Use 'what'.

Costello:   That's what I am trying to find out. Isn't that true ?

Abbott:     No. 'true' gives you 0.

Costello:   Which one ?

Abbott:     'true' gives you 0. 'which programname'

Costello:   Let's get back to my problem.
            What program? How do I find it?

Abbott:     Type 'find / -name it -print' to find 'it'.
            Type 'what program' to get the revision code.

Costello:   I want to find the revision code.

Abbott:     You can't 'find revisioncode', you must use 'what program'.

Costello:   Which command will do what I need?

Abbott:     No. 'which command' will find 'command'.

Costello:   I think I understand. Let me write that.

Abbott:     You can 'write that' only if 'that' is a user on your system.

Costello:   Write what?

Abbott:     No. 'write that'. 'what program'.

Costello:   Cut that out!

Abbott:     Yes! those are valid files for 'cut'.
            Don't forget the options.

Costello:   Do you always do this ?

Abbott:     'du' will give you disk usage.

Costello:   HELP!

Abbott:     'help' is only used for Source Code Control System (SCCS).

Costello:   You make me angry.

Abbott:     No, I don't 'make me' angry but I did 'make programname' when I
            was upset once.

Costello:   I don't want to make trouble, so no more.

Abbott:     No 'more'? 'which' will help you find 'more'.
            Every system has 'more'.

Costello:   Nice help! I'm confused more now!

Abbott:     Understand that since 'help' is such a small program, it is
            better not to 'nice help'. and 'more now' is not allowed but 'at
            now' is.  Unless of course 'now' is a file name.

Costello:   This is almost as confusing as my PC.

Abbott:     I didn't know you needed help with 'pc'.
            Let me get you to the Pascal compiler team. --

-- Author Unknown