From: ebel@lsesun3.epfl.ch (Norbert EBEL)
Newsgroups: comp.unix.questions
Subject: Re: Question: what is the unix equivalent of VMS's "verbs"??
Keywords: VMS, unix
Date: 20 Aug 92 16:05:50 GMT
Organization: Laboratoire de Systemes d'Exploitation - E P F Lausanne, Switzerland

In article <1992Aug2.001043.4958@u.washington.edu>, sue@byron.u.washington.edu (Shu-Chen Eclipse) writes:
|> Hellow,
I came also from VMS and suffered from some of the same ills You did. Let me give
you some advice which may help you become more cynical sooner in regard of Unix.
Life will be easier and you may even ENJOY Unix

1)When you ask a Unix guru you always get an answer which may be Do man blah or
just may be wrong. You NEVER get the following answer "Sorry I don't know". So...

2) Everything IS in the man pages, but most of the time not where you look,
or is hidden under a strange verb, or even when it is where it should you don't
see it because a man page is so unreadable

3) You must live with the fact that everything is only approximatly like you 
believe unless it was so under the last release or the other Unix you used last 
week

4) Unix is very simple has few concepts (but many many features) and so it is
in fact easy to learn

5) You should definitely read one simple Unix introductory Book
I will try to give you my answers to some of your questions

|> 
|> Just what is Unix's equivalent of VMS's "verbs"?

The first 'word' on a command line to the shell is the equivalent of the VMS
verb (the next ones are used as options or parameters, something like VMS)
When you are typing a command or Unix reads it from a script file it is a
ordinary promgram which reads it, This program is called the shell (ans is like
DCL in VMS. There are plenty of kinds of shells which looks very like BUT are
all different in some kind (sh, csh, tcsh, ksh, bash, ...)
Every one shell has a number of INTERNAL commands and if this command is not
known as internal, a path VARIABLE is searched through for looking if a program
with that same verb can be found there. So whether 'blah' is internal or not
or even is not available depends on the shell. ( To be able to know a priori if
a command can be or cannot be internal is a good measure if you get the good
feeling of your Unix. :-)
|> 
|> How does unix define its commands?
|> --let's see, correct me if I'm wrong:
|>    "alias" are the VMS equivalent of defining process global symbols for
|>      some command strings,

alias is an internal command of csh but not available on sh. It is then used
like a symbol definition in VMS
|> 
|>    "set" are like VMS's local symbol defininitions are only valid for the
|> login process and are not inherited by any spawned processes
|> 
|>   "setenv" are like VMS's global symbols, and are inherited by background
|> and spawned(?) processes.
mmhh mmhh ! approximatly
|> 
|>  -- but how are the strings like "set", "setenv", "fork", "fortran", "basic",
|> "awk","vi", etc defined for Unix? In vms, they're kept in dcltables.exe and
|> can be modified systems or per process (loca) -wide. What is Unix's equivalent
|> of "DCLTABLES.EXE". Does unix have vms's equivalent of PPF files?
|> 
|> What is unix's equivalent to VMS's hierachy of "logicals"??
Remember that in VMS you have 2 notions variables called symbols (only two kinds
local and globals) and logicals which are hierachical via the 4 tables, BUT the
important here is that the whole file system tries to make translation
implicitely. In Unix you have only variables, which must be asked for their values
via $. there is no hierarchy (well there are also globals and locals)
|> 
|> Does UNix have "batch" ques? "run/detached"?
|> Is "ln" unix's equivent of vms's "set file /enter" and backlins?
I would say so but see the distinction between hard links (like VMS) and 
symbolic links (man ln)
 Or more like
|> Vms's "logicals" for file/directory/device names?
|> 
|> What is unix's equivalent of vms's "set file watch"? does not exist, but can
be built in the kernel needs hard gurus.
|> Do unix shells have vms's equivalent of "lexical functions?" They dont exist
in the same manner but most informatuon and services you got via them on VMS can
bet gotten in an appropiate way on unix
|> Can you "install" images in Unix like in VMS??
No there is a 'better' solution with the setuid bit see chmod
|> -- well, I guess, I'm getting off track here, but just trying to make sense
|> of this VERRY difficult and rather EERRIE BEAST you guys call "UNIX".
|> 
|> thans for answering,
|> sue@ks 4 
|> byron.u.washington.edu
As a kind of exercice to get angry against unix : whow can you be told e-mail
has come. Try to finf that by man if you do'nt know it (the answer is biff y)

Norbert Ebel