link-roulette.fish

#!/usr/bin/env fish

set ORIGIN_DIR (dirname (readlink -m (status --current-filename)))
pushd $ORIGIN_DIR

set LINE_COUNT (cat unvisited-links.txt | wc -l)

set RANDOM_INDEX 0
function get-line
    set RANDOM_INDEX (random 1 $LINE_COUNT)
    head -n $RANDOM_INDEX unvisited-links.txt | tail -n 1
end

while true;
    set LINE_CONTENT (get-line)
    if [ $LINE_CONTENT != "" ];
        echo $RANDOM_INDEX $LINE_CONTENT
        echo $LINE_CONTENT >> visited-links.txt
        head -n (math $RANDOM_INDEX - 1) unvisited-links.txt > unvisited-temp.txt
        tail -n (math $LINE_COUNT - $RANDOM_INDEX) unvisited-links.txt >> unvisited-temp.txt
        mv -f unvisited-temp.txt unvisited-links.txt
        break
    end
end

popd