ldconfig

LDCONFIG(8)                Linux Programmer's Manual               LDCONFIG(8)



NAME
       ldconfig - configure dynamic linker run-time bindings

SYNOPSIS
       /sbin/ldconfig [-nNvXV] [-f conf] [-C cache] [-r root] directory...
       /sbin/ldconfig -l [-v] library...
       /sbin/ldconfig -p

DESCRIPTION
       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.
       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 libraries (i.e., libc5
       or libc6/glibc) based on what C libraries, if any, the library was
       linked against.

       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.

OPTIONS
       -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.

       -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
              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 quiet mode.

       -V, --version
              Print program version.

       -X     Don't update links.  Unless -N is also specified, the cache is
              still rebuilt.

FILES
       /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.

SEE ALSO
       ldd(1), ld.so(8)

COLOPHON
       This page is part of release 5.03 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
       https://www.kernel.org/doc/man-pages/.



GNU                               2017-09-15                       LDCONFIG(8)