On Monday 22 December 2008, Winter, G (Graeme) wrote:
> Dear Victor and BB,
>
> For reasons which are opaque at best some linux distributions
> name this file libtermcap.so, and some libtermcap.so.2.
This much I can explain, and since it is useful knowledge for
tracking down linux library problems in general, I'll post it to the
group. This is the general scheme:
You can have multiple, possibly incompatible versions of a shared library
installed on your system. They have names like
libfoo.so.5.0
libfoo.so.5.1
libfoo.so.6.0
Versions that differ only in the "minor" number are usually compatible
(e.g. 5.0 and 5.1), but versions that differ in the "major" version
generally are not (5.0 and 6.0). It is common that compatible versions
are installed with a symlink pointing to the most recent one:
libfoo.so.5 ---> libfoo.so.5.1
If you are running pre-built executables, you need to have a compatible
version installed. It could be any of the various versions you have,
and the loader will look for one that matches the version the program
was linked against when it was built.
So much for running pre-built programs.
If you are building a program from source, for every library it wants to
link to you generally need to have installed an additional package
containing a few extra files (for example header files *.h). Different
linux distros have different naming schemes but the one I am familiar
with appends -devel to the library package name:
libfoo.6.0.rpm # basic library package need to run old programs
libfoo.6.0-devel.rpm # additional files needed to build new programs
And finally we come back to Graeme's original point of opacity.
The *-devel package will install a chain of generic symlinks that points
to the newest of the library versions you have already installed:
libfoo.so --> libfoo.6
libfoo.6.so --> libfoo.6.0.so
Scripts that build a new program from source will look for the file
libfoo.so, and complain if they do not find it. But the library required
to actually _run_ the program is the one at the end of the chain of symlinks,
in this case libfoo.6.0.so
If you wanted to build a program that used an older version of the library,
perhaps so it could run on an older system, you could replace the symlink
manually:
libfoo.so --> libfoo.old.version.so
and then re-run the build script.
> Evidently the binary worked fine on the collection we tested. Fortunately
> there is a relatively simple if inelegant fix:
>
> cd $CLIB
> ln -s /usr/lib/libtermcap.so ./libtermcap.so.2
That is in fact the correct solution, and is exactly what the *-devel package
would do automatically for you. However, if the program actually needs to
link against the library then it probably needs to use the *.h header files
that also come with the *-devel package.
hope that helps,
Ethan
>
> This will just link to the system termcap library when used by Mosflm. If
> however Harry says that this is not used any more then we (CCP4) will need to
> check and update the Makefiles. I'll log this as something to check.
> Of course, fetching the version from Harry direct is an equally good solution.
>
> Best wishes,
>
> Graeme
>
>
>
> -----Original Message-----
> From: CCP4 bulletin board on behalf of Victor Alves
> Sent: Mon 12/22/2008 3:26 AM
> To: CCP4BB@JISCMAIL.AC.UK
> Subject: Re: [ccp4bb] ccp4-6.1.0: iMosflm libtermcap.so.2 error - SOLVED
>
>
>
> *
> *
> *
>
> Thank you all for responding on a Sunday. Don't you guys ever rest? :-)
>
>
>
> Computers never cease to surprise me.
>
>
>
> I checked my Ubuntu installation and, after all, libncurses5 is
> installed. But, contrary to the information in packages.ubuntu.com, I
> did not find "/usr/lib/libtermcap.so" or on any other place, in my
> laptop!
>
>
>
> At the same time I was looking on how to get this library, I also
> downloaded the imosflm zipped file and the ipmosflm executable from
> http://www.mrc-lmb.cam.ac.uk/harry/imosflm/, as Harry Powell suggested.
>
>
>
> Comparing my installation (it is an installation from binaries, Tim
> Gruene) with the contents of these new downloads:
>
> I added 14 new files starting with .# to dir ccp4-6.1.0/ccp4i/imosflm/src,
>
> I added tkImageLoad.so file to dir ccp4-6.1.0/ccp4i/imosflm/lib,
>
> I replaced ipmosflm (6.2 MB (6471568 bytes)) with the downloaded
> version (5.4 MB (5647272 bytes)) in /usr/local/xtal/ccp4/ccp4-6.1.0/bin
>
>
>
> And now the error message is gone and all is working fine!!
>
>
>
> I guess it was changing ipmosflm file who did the trick.
>
>
>
> Maybe the version that comes with ccp4 6.1.0 was, in my case, a buggy one??
>
>
>
> Until next time
>
>
>
> Thanks again
>
>
>
> Victor Alves
>
>
>
>
>
> Quoting "Johan P. Turkenburg" <j...@ysbl.york.ac.uk>:
>
> > Hi,
> >
> > You can use the website at packages.ubuntu.com to search for this file
> > in the contents (!) of the packages available for Entrepid.
> >
> > For libtermcap.so it tells you to install libncurses5-dev
> >
> > Install this using synaptic (the package manager).
> >
> > You may then have to create a link for libtermcap.so.2 by going to
> > /usr/lib/ (I assume that's where it will be installed) and doing
> > ln -s libtermcap.so libtermcap.so.2
> >
> > I can't test this, as I have decided to keep the LTS Hardy Heron.
> >
> > HTH
> >
> > Johan
> >
> >
> > Victor Alves wrote:
> >> Greetings
> >>
> >> And you say: - "Oh no! It's him again..."
> >>
> >> I know ... and even promised William Scott (in a private email) to
> >> not bother you again until Christmas, but...
> >>
> >> First question: is CCP4BB the proper channel for these questions
> >> and doubts? Or should I email directly the developers?
> >>
> >> As I said, this is a new laptop with a 32bits Ubuntu Intrepid Ibex
> >> 8.10 and a fresh new installation of ccp4 6.1.0.
> >>
> >> When I open iMosflm (whether from within the ccp4i or from the
> >> command line" I get an window with the following error message:
> >>
> >> iMosflm 1.0.0, 16th October 2008 (requiring Mosflm 7.0.4)
> >>
> >> iMosflm cannot run "usr/local/xtal/ccp4/ccp4-6.1.0/bin/ipmosflm":
> >>
> >> /usr/local/xtal/ccp4/ccp4-6.1.0/bin/ipmosflm: error while loading
> >> shared libraries: libtermcap.so.2: cannot open shared object file:
> >> No such file or directory
> >>
> >> Please configure iMosflm with the correct executable.
> >>
> >> I searched for libtermcap.so.2 and couldn't find it in my computer.
> >>
> >> Help please and thank you
> >>
> >> Victor Alves
> >>
> >>
> >>
> >> ----------------------------------------------------------------
> >> This message was sent using IMP, the Internet Messaging Program.
>
>
>
> ----------------------------------------------------------------
> This message was sent using IMP, the Internet Messaging Program.
>
--
Ethan A Merritt
Biomolecular Structure Center
University of Washington, Seattle 98195-7742
