Unix Tip: BOURNE SHELL PSEUDO HASH TABLES

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3067 - June 30, 2009

http://www.ugu.com/sui/ugu/show?tip.today

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

BOURNE SHELL PSEUDO HASH TABLES

The best way to explain this is with an example:

You may want to write a simple script that launches an xterm window with different color options. Pseudo hash tables in bourne shell.

$ xwindow MidnightBlue

An easy way to this is by first listing the supported colors in the script (pseudo hash table):

DarkSlateGrey="#2f4f4f"
DimGrey="#696969"
MidnightBlue="#191970"
NavyBlue="#000080"

Next, simply grab the hex color code by using the following command:

BGColor=`eval echo $"$(echo $1)"`

"$(echo $1)" evaluates to "MidnightBlue" and `eval echo $MidnightBlue evaluates to "#191970".

Simply launch the xterm window using $BGColor as the background color:

xterm -bg="$BGColor" &

This method for extracting pseudo hash values may be used for NIS map files, file date stamps, GUI colors, etc.

This tip generously supported by: Jasper.Silvis@PHL.Boeing.com

--------------------------------------------------------------------------
To Subscribe: http://www.ugu.com/sui/ugu/show?tip.subscribe
To Unsubscribe: http://www.ugu.com/sui/ugu/show?tip.unsubscribe
To Submit A Tip: http://www.ugu.com/sui/ugu/show?tip.today

==========================================================================
DISCLAIMER: All UNIX HOT TIPS ARE OWNED BY THE UNIX GURU UNIVERSE AND ARE
NOT TO BE SOLD, PRINTED OR USED WITHOUT THE WRITTEN CONSENT OF THE UNIX
GURU UNIVERSE. ALL TIPS ARE "USE AT YOUR OWN RISK". UGU ADVISES THAT
ALL TIPS BE TESTED IN A NON-PRODUCTION DEVELOPMENT ENVIRONMENT FIRST.

Unix Guru Universe - www.ugu.com - tips@ugu.com - Copyright 1994-2001
==========================================================================