#!/bin/sh
#
# Return the mailcap action for the supplied MIME type.
#	- Cameron Simpson <cs@zip.com.au> 14nov2002
#

mailcap=$HOME/.mailcap

action=1
subfile=
needattrs=
rejectattrs=

cmd=$0
usage="Usage: $cmd [-a] [+a] [-c] [+c] [-m mailcap] [-s subfile] mimetype [[!]attribute...]
	-a	Just print the action portion of the mailcap entry (default).
	+a	Print the whole mailcap entry.
	-c	Select the \"copiousoutput\" mailcap entry (default).
	+c	Avoid the \"copiousoutput\" mailcap entry.
	-m mailcap Specify the mailcap file.
	-s subfile Replace any %s with subfile, correctly quoted.
		   Actions with no %s get the file as stdin."

badopts=

aflag=
cflag=
subcmd="\"\$0\" $aflag $cflag -m \"\$mailcap\""

while :
do  case $1 in
      -a)	action=1 ;;
      +a)	action= ;;
      -c)	needattrs="$needattrs copiousoutput" ;;
      +c)	rejectattrs="$rejectattrs copiousoutput" ;;
      -m)	mailcap=$2; shift ;;
      -s)	subfile=$2; shift ;;
      --)	shift; break ;;
      -?*)	echo "$cmd: unrecognised option: $1" >&2; badopts=1 ;;
      *)	break ;;
    esac
    shift
done

if [ $# = 0 ]
then
  echo "$cmd: missing mime type" >&2; badopts=1
else
  mtype=$1; shift
fi

# gather up accept/reject attribute lists
for attr
do
  case "$attr" in
    !*) rejectattrs="$rejectattrs "`expr "x$attr" : 'x.\(.*\)'` ;;
    *)  needattrs="$needattrs $attr" ;;
  esac
done

[ $badopts ] && { echo "$usage" >&2; exit 2; }

grep "^$mtype *;" <"$mailcap" \
| \
{
  ok=
  while oIFS=$IFS
        IFS=';'
	read cap_type cap_action cap_attrs || break
	IFS=$oIFS
  do
    ok=1

    # make sure all the needed attributes are present
    for attr in $needattrs
    do  case " $cap_attrs " in
	  *" $attr "*)	;;
	  *)		ok=; break ;;
	esac
    done
    [ $ok ] || continue

    # make sure none of the reject attributes are present
    for attr in $rejectattrs
    do  case " $cap_attrs " in
	  *" $attr "*)	ok=; break ;;
	esac
    done
    [ $ok ] || continue

    break
  done

  [ $ok ] || exit 1

  [ $action ] || { echo "$cap_type; $cap_action; $cap_attrs"; exit 0; }

  [ -n "$subfile" ] || { echo "$cap_action"; exit 0; }

  # insert hook for $subfile
  qsubfile=`shqstr "$subfile"`
  case "$cap_action" in
      *'%s'*)
		# protect sed-specials
		case "$qsubfile" in
		  *[\&\\]*)	sedsubfile=`sedstrs 's/[&\\]/\\\\&/g' "$qsubfile"` ;;
		  *)		sedsubfile=$qsubfile ;;
		esac
		cap_action=`sedstrs "s%s$sedsubfileg" "$cap_action"`
		;;
      *)	[ "x$subfile" = x/dev/fd/0 ] || cap_action="exec <$qsubfile; $cap_action"
		;;
  esac

  echo "$cap_action"
}