oremanj at get-linux.org
Thu Aug 21 17:11:53 PDT 2003
On Thu, Aug 21, 2003 at 06:49:06PM -0500 or thereabouts, Walter wrote:
> Sorry to bother you, but the $RANDOM symbol returns
> a blank. Do I need to initialize something?
On bash/zsh $RANDOM returns a random number. On sh
it's apparently undefined. To define it, do
RANDOM=$( perl -e 'srand; print int(rand()*100000)%32767' )
> is there a shell command to extract the day of the
> month from the string returned by 'date'? I think
> now I'd prefer to do that.
To do that (if you don't have enough files in the directory
it will wrap around), do:
DIR=<<< the directory >>>
nfiles=$(ls -1 $DIR | wc -l | tr -d ' ')
fileno=$(( ($(date +%d) % $nfiles) + 1)
FILE=$DIR/$(ls -1 $DIR | head -n $fileno | tail -n 1)
(The command is "date +%d").
> Joshua Oreman wrote:
> >On Thu, Aug 21, 2003 at 11:36:24AM -0500 or thereabouts, Walter wrote:
> >>Hi All,
> >> I want to run a cron job to upload a different image
> >>file to a web site as a new background every night.
> >> I need a way to automatically select a different file
> >>from a directory which I will populate over time, and
> >>then feed that name to the upload script. I can't find
> >>anything like this in the ports. Can someone suggest
> >>a utility, script, et cetera, for this? Otherwise, I'm
> >>prepared to write my own, but I don't want to re-invent
> >>the wheel, as the saying goes. Thanks.
> >To select a random file from the directory, try this:-
> >DIR=<<< the directory >>>
> >nfiles=$(ls -1 $DIR | wc -l | tr -d ' ')
> >fileno=$(( ($RANDOM % $nfiles) + 1 ))
> >FILE=$DIR/$(ls -1 $DIR | head -n $fileno | tail -n 1)
> ># $FILE now contains the full pathname of the file to
> ># upload. I'm sure you can handle the upload task :-)
> ># Note: this script may re-use the same file later. To
> ># prevent this, add a line below the upload:
> ># mv $FILE /somewhere/else/
> ># That way the directory will only contain unused files.
> >-- Josh
> >> Please CC me as I'm not currently subscribed to the
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