#!/bin/ksh

function shdoc {
  typeset version="3.1, 2008-05-28, Michael Wang <xw73@columbia.edu>."

  typeset help doc file

  typeset    tmpdir=/tmp/shdoc_$$_$RANDOM
  typeset    base tmpf i flag=N

  eval help=y doc=pod "$@"

  [[ -n ${OPATH:-} ]] && typeset PATH=$OPATH

  set -- $(echo $help $doc | tr '[a-z]' '[A-Z]')
  help=$1 doc=$2

  base=${file##*/}
  base=${base%.*sh}

  case ${doc} in
    (POD) mkdir -p ${tmpdir}          && tmpf=${tmpdir}/${base}.pod        ;;  
    (MAN) mkdir -p ${tmpdir}/man/man1 && tmpf=${tmpdir}/man/man1/${base}.1 ;;
  esac

  while IFS= read -r i; do
    [[ $i = "## "* ]] && {
      [[ $i = "## ${doc}_START"* ]] && { flag=Y; continue; }
      [[ $i = "## ${doc}_STOP"*  ]] && { flag=N; continue; }
    }

    if [[ $flag = "Y" ]]; then
      i=${i#"##"}
      i=${i#" "}
      printf "%s\n" "${i}"
    fi
  done < ${file} > ${tmpf}

  case $help in
    (Y)      case ${doc} in
               (POD) perldoc ${tmpf}                   ;;
               (MAN) MANPATH=${tmpdir}/man man ${base} ;;
             esac
             ;;
    (PS|PDF) case ${doc} in
               (POD) pod2man --center=" " --date=" " --release="" ${tmpf} ;;
               (MAN) cat                                          ${tmpf} ;;
             esac |
               groff -man |
                 case ${help} in
                   (PS)  cat     >${base}.ps  ;;
                   (PDF) ps2pdf - ${base}.pdf ;;
                 esac
             ;;
    (POD)    cp ${tmpf} ${base}.pod
             ;;
    (HTML)   pod2html ${tmpf} > ${base}.html
             rm pod2htmd.tmp pod2htmi.tmp
             ;;
  esac

  rm -rf ${tmpdir}
  return 0
}

file=$1

[[ -z $file ]] && {
  print "Usage: $0 <file>"
  exit 1
}

type pod2man >/dev/null 2>&1 || {
  print "Please add pod2man to the PATH."
  exit 1
}

sed "/^## MAN_START/,/^## MAN_STOP/d" $file > $file.tmp

shdoc file=$file doc=pod help=pod

base=${file##*/}
base=${base%.*sh}

{
  print "## MAN_START"
  pod2man --center=" " --date=" " --release="" ${base}.pod | sed "s:^:## :"
  print "## MAN_STOP"
} >> $file.tmp

cp $file.tmp $file
rm $file.tmp ${base}.pod