hello,

from the ncurses package
why is it that multiple symlinks exist for the same library with an apparently ascending version number ?

regards

I'm willing to take an educated guess here:
Some applications are linked to the generic library name such as libncurses.so. I'd guess these are written using functions which are known to, or expected to, exist in all versions of the library the author expects to be in existence.
Some applications though might be written to use a specific function which appeared in, for example, libncurses.so.5 -- so they specify that version. obviously, though, this is a problem when the version is updated so simlinks are used until the relevant packages are likely to have been updated.
Sorry, I'm sure somebody who knows the exact process will be along soon, I just wanted to prove my ignorance.

1 members found this post helpful.

Exactly so!

Linux allows an application to either be "very specific" as to what library-version it wants, or very general. Let's say for the sake of example that you have versions 5.1, 5.7, and 4.9 of libcurses on your system, all at the same time. First of all, Linux is capable of handling that, "with grace and style." If an application simply asks for "libcurses," one of those symlinks will define what it will get. If it wants "libcurses 5" or "libcurses 4," ditto. And so on. The very-simple mechanism of symlinks provides the flexibility, and the loader cache (ldconfig) provides the speed.

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libfoo.so used by ld during program build
libfoo.so.X used by ld-linux when shared library is loaded
libfoo.so.X.Y - don't know. May be to show user exactly what version is used

thanks guys for the help

much appreciated !