LDCONFIG(8) Linux Programmer's Manual LDCONFIG(8)
ldconfig - configure dynamic linker run-time bindings
/sbin/ldconfig [-nNvXV] [-f conf] [-C cache] [-r root] directory...
/sbin/ldconfig -l [-v] library...
ldconfig creates the necessary links and cache to the most recent
shared libraries found in the directories specified on the command
line, in the file /etc/ld.so.conf, and in the trusted directories, /lib
and /usr/lib (on some 64-bit architectures such as x86-64, lib and
/usr/lib are the trusted directories for 32-bit libraries, while /lib64
and /usr/lib64 are used for 64-bit libraries).
The cache is used by the run-time linker, ld.so or ld-linux.so. ldcon-
fig checks the header and filenames of the libraries it encounters when
determining which versions should have their links updated.
ldconfig will attempt to deduce the type of ELF libraries (i.e., libc5
or libc6/glibc) based on what C libraries, if any, the library was
Some existing libraries do not contain enough information to allow the
deduction of their type. Therefore, the /etc/ld.so.conf file format
allows the specification of an expected type. This is used only for
those ELF libraries which we can not work out. The format is
"dirname=TYPE", where TYPE can be libc4, libc5, or libc6. (This syntax
also works on the command line.) Spaces are not allowed. Also see the
-p option. ldconfig should normally be run by the superuser as it may
require write permission on some root owned directories and files.
-c fmt, --format=fmt
(Since glibc 2.2) Cache format to use: old, new, or compat
Use cache instead of /etc/ld.so.cache.
Use conf instead of /etc/ld.so.conf.
(Since glibc 2.7) Ignore auxiliary cache file.
-l (Since glibc 2.2) Library mode. Manually link individual
libraries. Intended for use by experts only.
-n Process only the directories specified on the command line.
Don't process the trusted directories, nor those specified in
/etc/ld.so.conf. Implies -N.
-N Don't rebuild the cache. Unless -X is also specified, links are
Print the lists of directories and candidate libraries stored in
the current cache.
Change to and use root as the root directory.
Verbose mode. Print current version number, the name of each
directory as it is scanned, and any links that are created.
Overrides quiet mode.
Print program version.
-X Don't update links. Unless -N is also specified, the cache is
/lib/ld.so Run-time linker/loader.
/etc/ld.so.conf File containing a list of directories, one per
line, in which to search for libraries.
/etc/ld.so.cache File containing an ordered list of libraries found
in the directories specified in /etc/ld.so.conf, as
well as those found in the trusted directories.
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GNU 2017-09-15 LDCONFIG(8)