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 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  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 4.09 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/.

---

Free and Open Source Software