nhc: Fix detached mode result writability test

In detached mode, we check to see if we can write to the result file
before actually trying to do so, but `test -w` returns false for
non-existent files, not just unwritable files.  So we need to redo the
logic of that test to account for both cases: (1) file exists and is
writable, or (2) file does not exist but directory does and is
writable.

While I was at it, I also changed where the write is done to account
for a third scenario:  (3) everything looks like it should work but
the write itself fails.

Fixes #59.  Thanks to @hwj0303 for spotting this!

nhc

@@ -61,11 +61,11 @@ function die() {
  fi
  fi
  if [[ -n "$NHC_DETACHED" ]]; then
- if [[ -w "$RESULTFILE" ]]; then
- echo "$RET $*" > $RESULTFILE
+ if [[ -w "$RESULTFILE" || (! -e "$RESULTFILE" && -w "${RESULTFILE%/*}") ]] && echo "$RET $*" > $RESULTFILE ; then
+ dbg "Wrote results file $RESULTFILE: $RET $*"
  else
- log "ERROR: $NAME: Unable to write to \"$RESULTFILE\" -- is ${RESULTFILE%/*} read-only?"
- syslog "ERROR: $NAME: Unable to write to \"$RESULTFILE\" -- is ${RESULTFILE%/*} read-only?"
+ log "ERROR: $NAME: Unable to write to \"$RESULTFILE\" -- is ${RESULTFILE%/*} missing/read-only?"
+ syslog "ERROR: $NAME: Unable to write to \"$RESULTFILE\" -- is ${RESULTFILE%/*} missing/read-only?"
  syslog_flush
  fi
  elif [[ "$NHC_RM" == "sge" ]]; then