Re: pretty easy thing but too hard for me! (random array element)

["Brian K. White" <brian@xxxxxxxxx>]

----- Original Message ----- 
From: "fREW" <frioux@xxxxxxxxx>
To: "Zsh users list" <zsh-users@xxxxxxxxxx>
Sent: Wednesday, August 01, 2007 5:23 PM
Subject: pretty easy thing but too hard for me! (random array element)


> Hello zsh amigos!
>
> I want to make a tiny fuction that will
>
> #1 get a list of files
> #2 choose a random file
> #3 open the random file
>
> I was going to just do something like
>
> arr=( * )
>
> and then
>
> feh $arr[(some random number or something)]
>
> but I don't know how to do the random number part and there may be a
> better way anyway.  Thoughts?  Ideas?  Wisdom?
>
> --
> -fREW
>
> Q: Why is this email 5 sentences or less?
> A: http://five.sentenc.es


I have a random splash thing where as part of my companies software the 
start script flashes an ascii splash logo for a half-second on start-up. I 
got bored one day, found a ascii art font generator thing on line that let 
me plug in our name and get large ascii art renditions of it in about 30 
differentr fonts.

I did something cruder even than loading up an array. It requires the files 
have consecutive numerical filenames and just applies $RANDOM and a little 
math directly.
But it works in bash/ksh/zsh and doesn't require zsh or a zsh module
I wouldn't be surprised if both uses of backticks are avoidable somehow.
Since even my SCO boxes all have zsh by now redoing this with the randline 
thing has appeal.

-----
#!/bin/sh
# Select a splash at random and display it.
# requires bash/ksh/zsh
# 20060411 brian@xxxxxxxxx
# put as many splash files as you want in /u/aljex/splash
# use only 3-digit, zero padded, numerical, consecutive filenames
# starting with 000

SplashDir=/u/aljex/splash

cd $SplashDir || exit 1
typeset -i SplashQty=`echo * |wc -w`
typeset -i RandomDivider=$((32767/$SplashQty))

RandomSelection=`printf "%03d" $((RANDOM/$RandomDivider))`

# The math is slightly off
# .1% of the time RandomSelection == SplashQty, which is 1 too high.
# Never comes out below 0 but what the heck, might as well catch that too.
[ $RandomSelection -lt 000 ] && RandomSelection=000
[ $RandomSelection -ge $SplashQty ] && RandomSelection=$((SplashQty-1))

echo
cat $RandomSelection
echo
sleep ${1:-.5}
-----


Brian K. White    brian@xxxxxxxxx    http://www.myspace.com/KEYofR
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