ksh math

From: Cohen, Andy <Andy.Cohen_at_cognex.com>
Date: Wed, 30 Jun 2004 16:09:32 -0400

I don't know what I'm missing -- all I want to do is do some very basic math on a variable but I can't figure it out. I've searched the archives, google, manuals, etc. and can't find anything that clarifies it.

I have a variable $RUN_DAY and I want to subtract one (1) from it. How do I do that?

I thought it would be:

    export PREV_DAY=${RUN_DAY}-1

but it doesn't work. I've tried quite a number of variations on this all to no avail.

I'm using:
    Tru64 5.1A
    korn shell (ksh)


Thank you!
Andy Cohen
Database Systems Administrator
Cognex Corporation
1 Vision Drive
Natick, MA 01760
508-650-3079
Received on Wed Jun 30 2004 - 20:11:19 NZST