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From: philip@cel.cummins.com (Philip D. Pokorny)
Newsgroups: comp.sys.apollo
Subject: Re: AEGIS Shell argument processing...
Message-ID: <9106131931.AA08669@cel.cummins.com>
Date: 13 Jun 91 19:31:14 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 50

Doug Vander Wilt writes:

>  After many years programming with the AEGIS shell (/com/sh) I wonder if
>  I'm missing out on some easier argument processing methods.  Is there a
>  "shift" style command to shift arguments left?  I haven't had any success
>  referring to them with a variable index, e.g.: ^0 ^1 .. ^^n
>  
>  I currently use the following form to process an unknown number of shell
>  arguments, but it won't properly handle quoted arguments:
>  (e.g.: $ argtest a 'b c' d )


I remember having to do something like this when proccessing the
equivalent of a shell array...  Here's what I came up with:

#!/com/sh
# Print shell arguments.
eon

n := 0

while(( ^"set -c args @^^n" <> "" )) do
   arg := ^"set -c args @^^n"
   args (( "Argument " + ^n + ": " + ^arg ))
   n := ^n + 1
enddo


This uses indirection via the 'set -c' shell command to evaluate
the argument @^^n once (to ^3, etc) and then again. (to get the
third argument, etc)  The down-side to this scheme is that you
may have to be carefull about null strings as arguments.  (You
could check all 127 arguments or if you are expecting an argument
that might be null it's not a problem.)

A sample run:

   $ test.sh 1 2 3 '^1' '4 5'
   Argument 0: test.sh
   Argument 1: 1
   Argument 2: 2
   Argument 3: 3
   Argument 4: ^1
   Argument 5: 4 5
   $ 

Sincerely,
Philip D. Pokorny
philip@cel.cummins.com
:)