Karl Berry wrote on 2006-02-13:
> Bruce Korb implemented a library for straightforward config file
> parsing (among other things). We thought it would make sense to use it
> for GNU Hello, as an example of how it can be done.
How come so few programs use this libopts? Let me look at the syntax of
the various .??* files in my home directory.
Plain list of keyword / value pairs:
.RealNetworks_RealMediaSDK_60
.RealNetworks_RealPlayer_60
.RealNetworks_RealShared_00
.appletviewer
.asadminprefs
.emiclockrc
.flexlmrc
.jaxe
.kapptemplaterc
.lincityrc
.lynxrc
.mailcap
.mainactorrc
.mcoprc
.mh_profile
.mtvrc
.pinerc
.tkcvs
.urlview
.xtalkrc
X11 resources syntax:
.Xdefaults
.Xresources
.acrorc
.gv
.nedit
.weblink
List of keyword / value pairs, with groups and parametrized keywords:
.fvwmrc
Nested groups of C-like compound statements with braces and semicolons:
.balsarc
Keywords with nested groups of C-like compound statements as values:
.twmrc
Parametrized keywords with nested groups of C-like compound statements as
values:
.gtkrc
Windows ini syntax ([Group]s of Keyword=Value statements):
.XaraLX
.dmrc
.kderc
.realplayerrc
.rpmfind
.serc
.sversionrc
.thotrc
.uitrc.*
.yuditrc
Other groups of keyword / value pairs:
.autom4te.cfg
Scripting language with at least conditional statements:
shell:
.bashrc
.profile
.xim
.xinitrc
.xserverrc
.xsession
Lisp:
.clinit.cl
.clisprc
.sbclrc
.talkrc
Emacs-Lisp:
.emacs
.emacs-places
vim:
.exrc
.vimrc
C-like:
.xcoralrc
Other:
.fpc.cfg
.inputrc
XML:
.com.zerog.registry.xml
.fonts.conf
List of numbers:
.clockrc
Single identifier:
.craftyrc
.wmrc
Other custom text format:
.Bfs
.DCOPserver
.MCOP-random-seed
.Xmodmap
.addressbook.lu
.dvipsrc
.fonts.cache-1
.gcalrc
.gtk_qt_engine_rc
.install4j
.ispell_english
.jazz
.kermrc
.lyxrc
.mime.types
.muttrc
.nc_keys
.rhosts
.stonxrc
.tex
.valgrind.supp
.viminfo
.workmanrc
.xmbdfedrc
.zsh
Binary format:
.B.blend
.Bfont
.ICEauthority
.Xauthority
.esd_auth
.fterc
.tamaga.dat
It appears that different programs have wildly different needs in this area...
> Of course, it involves a new Autoconf macro to test whether the library
> is available. And of course again, I don't want that macro to live in
> GNU Hello, since the goal is not Hello functionality, it's to be an
> example. So I want it to be in a common place. Which I guess is
> gnulib.
Why not have libopts itself provide and install the autoconf macro that
recognizes it?
> +AC_DEFUN([ag_FIND_LIBOPTS],
> + [if test "X${ac_cv_header_autoopts_options_h}" == Xno
> + then
> + :
> + else
> + f=`autoopts-config cflags` 2>/dev/null
> + test X"${f}" = X && f=`libopts-config cflags` 2>/dev/null
These xyz-config scripts have two flaws by design:
1) They don't support using the library with a different compiler than the
one that built it. Indeed, the CFLAGS that are supported by one compiler
are not supported by other compilers. Likewise for the "-Wl,-R/usr/lib"
option reported as being present in `autoopts-config ldflags`: it does
not work when the compiler is not gcc.
2) They expect to be found in PATH. I.e. in order to use packages installed
in /foo/bar, it is no longer sufficient to set
CPPFLAGS=-I/foo/bar/include
LDFLAGS=-L/foo/bar/lib
but it's also needed to set
PATH=/foo/bar/bin:$PATH
Better use the AC_LIB_LINKFLAGS or AC_LIB_HAVE_LINKFLAGS macro from gnulib.
It doesn't have these flaws.
Bruno
