#compdef getconf

local expl ret=1

local -a syskeys posixkeys confkeys pathkeys1 pathkeys2 allkeys mykeys restkeys
syskeys=(ARG_MAX BC_BASE_MAX BC_DIM_MAX BC_SCALE_MAX
  BC_STRING_MAX CHILD_MAX COLL_WEIGHTS_MAX EXPR_NEST_MAX LINE_MAX
  NGROUPS_MAX OPEN_MAX RE_DUP_MAX STREAM_MAX TZNAME_MAX)
posixkeys=(_POSIX_CHILD_MAX _POSIX_LINK_MAX
  _POSIX_MAX_CANON _POSIX_MAX_INPUT _POSIX_NAME_MAX _POSIX_NGROUPS_MAX
  _POSIX_OPEN_MAX _POSIX_PATH_MAX _POSIX_PIPE_BUF _POSIX_SSIZE_MAX
  _POSIX_STREAM_MAX _POSIX_TZNAME_MAX _POSIX_VERSION
  POSIX2_BC_BASE_MAX POSIX2_BC_DIM_MAX POSIX2_BC_SCALE_MAX
  POSIX2_BC_STRING_MAX POSIX2_COLL_WEIGHTS_MAX POSIX2_EXPR_NEST_MAX
  POSIX2_LINE_MAX POSIX2_RE_DUP_MAX POSIX2_VERSION POSIX2_C_BIND
  POSIX2_C_DEV POSIX2_FORT_DEV POSIX2_FORT_RUN POSIX2_LOCALEDEF
  POSIX2_SW_DEV _XOPEN_VERSION)
confkeys=(PATH GNU_LIBC_VERSION GNU_LIBPTHREAD_VERSION
  LFS_CFLAGS LFS_LDFLAGS LFS_LIBS LFS_LINTFLAGS
  LFS64_CFLAGS LFS64_LDFLAGS LFS64_LIBS LFS64_LINTFLAGS)
pathkeys1=(PIPE_BUF _POSIX_CHOWN_RESTRICTED
  _POSIX_NO_TRUNC _POSIX_VDISABLE)
pathkeys2=(LINK_MAX MAX_CANON MAX_INPUT NAME_MAX PATH_MAX PIPE_BUF)
mykeys=($syskeys $posixkeys $confkeys $pathkeys1 $pathkeys2)

if [[ CURRENT -eq 2 ]]; then
  _tags syswideconfig pathconfig standardsconfig confstring restconfig

  allkeys=(${${(f)"$(getconf -a 2>/dev/null)"}%%[: ]*})
  restkeys=(${allkeys:|mykeys})

  while _tags; do
    _requested -V syswideconfig expl 'systemwide configuration variables' \
      compadd -S '' $syskeys && ret=0

    _requested -V standardsconfig \
        expl 'system-standards configuration variables' \
      compadd -S '' $posixkeys && ret=0

    _requested -V confstring \
        expl 'configuration-dependent string variables' \
      compadd -S '' $confkeys && ret=0

    _requested pathconfig &&
    while _next_label -V pathconfig expl 'system path configuration variables'; do
      compadd "$expl[@]" -S '' $pathkeys1 && ret=0
      compadd "$expl[@]" -S ' ' $pathkeys2 && ret=0
    done

    if (( ${#restkeys} )); then
      _requested -V restconfig \
	expl 'remaining unclassified configuration variables' \
	compadd -S '' $restkeys && ret=0
    fi

    (( ret )) || return 0
  done
else
  _files -/
fi