#!/usr/bin/env zsh
setopt ERR_EXIT
fpath=($0:h:a/cmd/functions.zsh $fpath)
autoload url-to-filename
typeset -A seen
while read url ; do
    url="$url " # to be sure that next line will work
    url=${${=url}[1]}
    dir=feeds/$(url-to-filename $url)
    seen[$dir]=1
    [[ -e $dir ]] && continue || :
    mkdir -p $dir/{cur,new,tmp} # make it maildir
    print -- "$url" > $dir/url
    print $dir
done
for dir (feeds/*) [[ $seen[$dir] -eq 1 ]] || print disappeared: $dir