ldconfig — configure dynamic linker run-time bindings
−f conf ] [
−C cache ] [
−r root ] directory...
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
/usr/lib (on some 64-bit
architectures such as x86-64, lib and
/usr/lib are the trusted directories for
32-bit libraries, while
/usr/lib64 are used for
The cache is used by the run-time linker, ld.so or ld-linux.so. ldconfig 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 libs (i.e., libc5 or libc6/glibc) based on what C libs, if any, the library was linked against.
Some existing libs 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
libs 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
−p option. ldconfig should normally be
run by the superuser as it may require write permission on
some root owned directories and files.
(Since glibc 2.2) Cache format to use: old, new, or compat (default).
(Since glibc 2.7) Ignore auxiliary cache file.
(Since glibc 2.2) Library mode. Manually link individual libraries. Intended for use by experts only.
Only process directories specified on the command
line. Don't process the trusted directories, nor those
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
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.
Don't update links. Unless
−N is also specified, the cache
is still rebuilt.
File containing a list of directories, one per line, in which to search for libraries.
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.
This page is part of release 4.07 of the Linux
man-pages project. A
description of the project, information about reporting bugs,
and the latest version of this page, can be found at
Copyright 1999 SuSE GmbH Nuernberg, Germany
Author: Thorsten Kukuk <kukuksuse.de>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public
License along with this manual; if not, see
Modified, 6 May 2002, Michael Kerrisk, <mtk.manpagesgmail.com>
Change listed order of /usr/lib and /lib