PATCH: new chmod completion

[Oliver Kiddle <okiddle@xxxxxxxxxxx>]

Like _chown, it will only complete files for which the command would be
meaningful so after chmod -x, you'll only get executable files.

It doesn't handle some of the more obscure types of priviliges as they
would be very hard to do in shell code (and a lot more easily handled by
extending the C code for the f glob qualifier).

I've only tested this on Linux and Solaris so if any other UNIX has
different options or doesn't like it running chmod --version to check
for GNU then let me know.

Oliver

#compdef chmod

local curcontext="$curcontext" state line ret=1
local -a args privs

args=( '*:file:->files' )
(( $+words[(r)--reference*] )) || args+=( '1:mode:->mode' )

if _pick_variant gnu=Free\ Soft unix --version; then
  args+=(
    '(-v --verbose -c --changes)'{-c,--changes}'[report changes made]'
    '(-v --verbose -c --changes)'{-v,--verbose}'[output a diagnostic for every file processed]'
    '(-f --silent --quiet)'{-f,--silent,--quiet}'[suppress most error messages]'
    '--reference=[copy permissions of specified file]:file:_files'
    '(-R --recursive)'{-R,--recursive}'[change files and directories recursively]'
    '(- : *)--help[display help information]'
    '(- : *)--version[display version information]'
  )
  privs=(
    'X[execute only if executable to another]'
    "u[owner's current permissions]"
    "g[group's current permissions]"
    "o[other's current permissions]"
  )
else
  # based on $OSTYPE = solaris2.8
  args+=(
    '-f[suppress most error messages]'
    '-R[change files and directories recursively]'
  )
  privs=( 'l[mandatory locking]' )
fi

_arguments -C -s "$args[@]" && ret=0

case "$state" in
  mode)
    compset -P \*,
    compset -S ,\*
    if [[ -prefix [0-7] ]]; then
      _message -e number 'numeric mode'
    elif compset -P '[a-z]#[+-=]'; then
      _values -S '' privilege \
	'r[read]' 'w[write]' 'x[execute]' \
	's[set uid/gid]' 't[sticky]' \
	"$privs[@]" && ret=0
    else
      suf=( -S '' )
      compset -P '*'
      _alternative -O suf \
	'who:who:((u\:user g\:group a\:all o\:others))' \
	'operators:operator:(+ - =)'
    fi
  ;;
  files)
    if [[ -n $opt_args[--reference] ]]; then
      if zstyle -t ":completion:${curcontext}:" disable-stat; then
	_files && ret=0
      else
	zmodload -i zsh/stat 2>/dev/null
	typeset -i8 ref=$(stat +mode $opt_args[--reference])
	_wanted files expl file _files -g "*(-.^f${ref#??})" && ret=0
      fi
    elif [[ $words[2] = [0-7]## ]]; then
      _wanted files expl file _files -g "*(-.^f$words[2])" && ret=0
    else
      local spec who op priv
      local -a specs
      for spec in ${(s:,:)words[2]}; do
	if [[ ${spec#*[+-=]} != [rwxst]* ]]; then
	  _files && ret=0
	  return ret
	fi

	specs+=( ${${(M)spec##[+-=]*}:+a}$spec )
      done
      _wanted files expl file _files -g "*(-.^f:${(j.,.)specs}:)" && ret=0
    fi
  ;;
esac

return ret