#!/bin/sh -u
#
# Examine the named files and attach correct extensions to misnamed ones.
#	- Cameron Simpson <cs@zip.com.au> 22feb1999
#
# Base entirely on file2mime and mimeext now. - cameron 24jul2003
# Added "-i type" option to bypass file2mime. - cameron 19apr2005
#

cmd=$0
usage="Usage: $cmd [-i type] [filenames...]
  -i type	Specify the MIME type instead of guessing from content."

itype=
[ $# -gt 0 ] && [ "x$1" = x-i ] && { itype=$2; shift; shift; }

[ $# = 0 ] && { [ -t 0 ] && echo "$cmd: reading filenames from stdin..." >&2; set -- `cat` || exit 1; }

xit=0

for f
do
  [ -f "$f" ] || { echo "$cmd: $f: not a regular file" >&2
                   xit=1; continue;
                 }
  [ -s "$f" ] || { echo "$cmd: $f: empty file!" >&2
                   xit=1; continue;
                 }

  if [ -n "$itype" ]
  then
    type=$itype
  else
    type=`file2mime "$f"` || { echo "$cmd: can't deduce MIME type of \"$f\"" >&2
                               xit=1
                               continue
                             }
  fi

  prefext=`mimeext "$type"` || { echo "$cmd: no preferred extension for $type" >&2
                                 xit=1
                                 continue
                               }

  # see if ext is ok already
  fbase=`basename "$f"`
  case "$fbase" in
    *".$prefext")	[ -t 1 ] || echo "$f"; continue ;;
  esac

  fdir=`dirname "$f"`
  case "$fdir" in
      .)	fdir= ;;
      *)	fdir=$fdir/ ;;
  esac

  case $f in
      *.*)	newf=$fdir`expr "x$fbase" : 'x\(.*\)\..*'`.$prefext ;;
      *)	newf=$fdir$fbase.$prefext ;;
  esac

  [ -t 1 ] && echo "$f -> $newf"
  mv -i -- "$f" "$newf" || xit=1
  [ -t 1 ] || echo "$newf"
done

exit $xit