:: Re: [DNG] Managing shared libraries
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Szerző: Joel Roth
Dátum:  
Címzett: dng
Tárgy: Re: [DNG] Managing shared libraries
On Sat, Oct 07, 2023 at 08:02:37PM +0300, Boian Bonev via Dng wrote:
> Hi,
>
> On Thu, 2023-10-05 at 00:06 +0200, aitor wrote:
> > Hi Joel,
> > On 4/10/23 3:06, Joel Roth via Dng wrote:
> > A likely way forward is to place the 6.3
> > sources in /usr/include/readline and compile
> > against that.
> > You can define a separate pkgconfig file for 6.3, say "readline6.pc", as follows:
> >
> > prefix=/usr
> > exec_prefix=${prefix}
> > libdir=${prefix}/lib
> > includedir=<put_here_the_path_you_want>
> >
> > Name: Readline
> > Description: Gnu Readline library for command line editing
> > URL: http://tiswww.cwru.edu/php/chet/readline/rltop.html
> > Version: 6.3
> > Requires.private: tinfo
> > Libs: -L${libdir} -lreadline
> > Cflags: -I${includedir}
> >
> > Note that I've also moved the path to the shared library from "/usr/lib/x86_64-linux-gnu"
> > to "/usr/lib". Obviously, you need to create the symlinks at "/usr/lib" for 6.3.
> >
> > In doing so, both versions 6.3 and 8.2 can coexist.
> > Now, to link against version 6.3:
> > `pkg-config --cflags --libs readline6`
> >
> > I would also like to compile against 8.1, but can I (and do
> > I need to) point the symlink at 8.1 without breaking things
> > like bash that depend on version 8.2?
> > I don't think it would break bash. But this is a guess. Either way, you can always use LD_PRELOAD.
> > For example:
> > $ LD_PRELOAD=/lib/x86_64-linux-gnu/libreadline.so.8
> > Cheers,
> > Aitor.
>
> That will not work - -lreadline will use /usr/lib/ARCH/libreadline.so
> which is a symlink that comes from the -dev package and is always
> pointing to the latest version. The older versions of the shared
> library provide only /usr/lib/ARCH/libreadline.so.VER for not breaking
> old programs that were linked to an older version of the library.
>
> Manually changing the link is OK - that will not break anything.
>
> The proper way to compile against an older version is to install the
> respective -dev package (that will conflict with all newer/older -dev
> packages).
>
> A side suggestion to the OP is to check libedit or linenoise, maybe
> they already have some perl bindings...


Hi Boian and others, many thanks for the informative replies,

I've found a solution that doesn't require an older readline.

happy hacking to all! and to all a good night!


--
Joel Roth