#!/bin/sh

# edit with locking

if [ "$1" = "" ]; then 
  cat <<EOD;
edit with (POSIX) locking
usage: `basename $0` filename [options]
options may be any of your \$EDITOR options
EOD
  exit
fi

file=$1
shift

if [ ! -f $file ]; then
  echo "$0: $file does not exist" >&2
  exit 1
fi

if [ ! -w $file ]; then
  echo "$0: $file is not writeable" >&2
  exit 1
fi

wlock -s $file ${EDITOR:-vi} "$@" $file || wlock -vt $file