zsh/Completion/Unix/Command/_getconf

#compdef getconf

local expl ret=1

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

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

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

    _requested -V confstring \
        expl 'configuration-dependent string variables' \
      compadd -S '' PATH GNU_LIBC_VERSION GNU_LIBPTHREAD_VERSION \
          LFS_CFLAGS LFS_LDFLAGS LFS_LIBS LFS_LINTFLAGS \
	  LFS64_CFLAGS LFS64_LDFLAGS LFS64_LIBS LFS64_LINTFLAGS \
	  && ret=0

    _requested pathconfig &&
        while _next_label -V pathconfig expl 'system path configuration variables'; do
          compadd "$expl[@]" -S '' PIPE_BUF _POSIX_CHOWN_RESTRICTED \
                                   _POSIX_NO_TRUNC _POSIX_VDISABLE && ret=0
          compadd "$expl[@]" -S ' ' LINK_MAX MAX_CANON MAX_INPUT NAME_MAX \
                                    PATH_MAX PIPE_BUF && ret=0
        done
    (( ret )) || return 0
  done
else
  _files -/
fi