#! /bin/sh
#
# magic $name $command $file < $content
#

name="$1"; shift
command="$1"; shift
file="$1"; shift

bs="# begin krebs magic${name+ <$name>}"
es="# end krebs magic${name+ <$name>}"

case $1 in
  (print)
    echo "$bs"
    cat
    echo "$es"
    ;;
  (create)
    $0 has || $0 print >> $file < /dev/null
    $0 replace
    ;;
  (destroy)
    if $0 has; then
      cache"`cat $file`"
      echo "$cache" | sed "/^$bs$/,/^$es$/d" > $file
    fi
    ;;
  (has)
    grep -q "^$bs\$" $file && grep -q "^$es\$" $file
    ;;
  (replace)
    $0 destroy && $0 create
    ;;
  (clear)
    $0 replace < /dev/null
    ;;
  (*)
    echo 'Error 1: You are made of stupid!' >&2
    exit 23
esac