Unix Tip: BOURNE SHELL PSEUDO HASH TABLES

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UNIX HOT TIP

Unix Tip 3457 - July 28, 2015

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

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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




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