ldconfig - configure dynamic linker run-time bindings
] [ -f conf
] [ -r root
creates the necessary links and cache to the most recent shared
libraries found in the directories specified on the command line, in the file
, and in the trusted directories, /lib
(on some 64-bit architectures such as x86-64, lib
are the trusted directories for 32-bit libraries, while
are used for 64-bit libraries).
The cache is used by the run-time linker, ld.so
checks the header and filenames of the libraries it encounters
when determining which versions should have their links updated.
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 the -p
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 (default).
- -C cache
- Use cache instead of /etc/ld.so.cache.
- -f conf
- Use conf instead of /etc/ld.so.conf.
- -i, --ignore-aux-cache
- (Since glibc 2.7) Ignore auxiliary cache file.
- (Since glibc 2.2) Library mode. Manually link individual
libraries. Intended for use by experts only.
- 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.
- Don't rebuild the cache. Unless -X is also
specified, links are still updated.
- -p, --print-cache
- Print the lists of directories and candidate libraries
stored in the current cache.
- -r root
- Change to and use root as the root directory.
- -v, --verbose
- Verbose mode. Print current version number, the name of
each directory as it is scanned, and any links that are created. Overrides
- -V, --version
- Print program version.
- Don't update links. Unless -N is also specified, the
cache is still rebuilt.
- Run-time linker/loader.
- 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 4.10 of the Linux man-pages
description of the project, information about reporting bugs, and the latest
version of this page, can be found at