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Re: [crypto] Select a file randomly



On Sat, Nov 10, 2001 at 01:57:19PM -0800, Karsten M. Self wrote:
> on Fri, Nov 09, 2001 at 03:55:37PM -0500, guillaume (triton@madchat.org) wrote:
> > Sorry for the off-topic, but I like this list ;)
> > 
> > I'm planing on doing a little software, in C or
> > simply shell code to help users like me use crypto.
> > 
> > Write message -> GPG crypto -> Jpeg Stegano -> Mail
> > 
> > For the Jpeg stegano part, I need to select a file
> > randomly from a base of pictures. 
> > 
> > Is there a GNU utility that allready does that ?
> 
> Fortune.
> 
> Several routines in Perl are posted regularly to various lists.

	I wrote a digital pictureframe-like script which uses something
like:

find $1 -iname '*jpg' | grep -v .xvpics > /tmp/imagelist
lines=`cat /tmp/imagelist | wc -l`

while [ true ]; do
    wowie=$RANDOM

    lines=$[$lines - 1]
    echo Lines = $lines

    if [ $lines = 1 ]; then
        echo "time to start over"
        find $1 -iname '*jpg' | grep -v .$[$wowie % $lines]xvpics > /tmp/imagelist
        lines=`cat /tmp/imagelist | wc -l`
    fi

    ra=$[($wowie % ($lines - 1)) + 1]
    
    echo Random = $ra

    fname=`head -n $ra /tmp/imagelist | tail -n 1`

    echo "Filename: $fname"

    if [ -r "$fname" ]; then
        echo "I can read it."

        grep -v "$fname" /tmp/imagelist > /tmp/imagelist2
        rm /tmp/imagelist
        mv /tmp/imagelist2 /tmp/imagelist

	blah blah blah...

	not cryptographically secure, but maybe that doesn't matter....

-- 
                                            Audin Malmin - audin@okb-1.org



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