#!/bin/ksh -p
# "The pied piper" (say pie-edd not pie'd :)

# Sends marked sections of a file through a pipe and not non marked
# sections
# e.g. pied rot13 @@ file
# on file = "Hello           "Hello
#            @@       __\     @@
#            Hello    ===>    Uryyb
#            @@       ""/     @@
#            Hello"           Hello"
# Provided you have a unix pipe called "rot13"
#
# Usage: pied pipename marker filename
# Usage in pine:
#     1) Select alternate editor (having none set)
#     2) Type: pied pipename marker
#        Note there's no filename!

set -A params $*

plen=${#params[*]}

plen=$((plen-1))
filename="${params[$plen]}"
  unset params[$plen]

plen=$((plen-1))
marker="${params[$plen]}"
  unset params[$plen]

OLDpipe="$(print ${params[*]})"
pipe=cat

set -o noglob
while read line ; do
    if [ "$line" == "$marker" ] ; then
        temp="$pipe"
        pipe="$OLDpipe"
        OLDpipe="$temp"
    fi
    echo $line | $pipe >> ${filename}.2
done < $filename
set +o noglob

mv -f ${filename}.2 ${filename}