ldconfig(g)                                           ldconfig(g)



NAME
       ldconfig - determine run-time link bindings

SYNOPSIS
       ldconfig [OPTION...]

DESCRIPTION
       ldconfig creates the necessary links and cache (for use by
       the run-time linker, ld.so)  to  the  most  recent  shared
       libraries  found  in the directories specified on the com-
       mand line, in the file /etc/ld.so.conf, and in the trusted
       directories  (/usr/lib  and  /lib).   ldconfig  checks the
       header and file names of the libraries it encounters  when
       determining   which   versions  should  have  their  links
       updated.  ldconfig ignores symbolic  links  when  scanning
       for libraries.

       ldconfig  will attempt to deduce the type of ELF libs (ie.
       libc5 or libc6/glibc) based on what  C  libs  if  any  the
       library  was linked against, therefore when making dynamic
       libraries, it is wise to explicitly link against libc (use
       -lc).

       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 only used for those ELF libs which
       we   can   not   work   out.   The  format  is  like  this
       "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.

       Directory names containing an = are no longer legal unless
       they also have an expected type specifier.

       ldconfig  should  normally  be run by the super-user as it
       may require write permission on some root  owned  directo-
       ries  and  files.   It  is  normally  run automatically at
       bootup, from /etc/rc, or manually whenever new  DLL's  are
       installed.

OPTIONS
       -v --verbose
              Verbose  mode.   Print  current version number, the
              name of each directory as it  is  scanned  and  any
              links that are created.

       -n     Only  process  directories specified on the command
              line.   Don't  process  the   trusted   directories
              (/usr/lib   and   /lib)   nor  those  specified  in
              /etc/ld.so.conf.  Implies -N.

       -N     Don't rebuild the cache.  Unless -X is also  speci-
              fied, links are still updated.

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

       -f conf
              Use conf instead of /etc/ld.so.conf.

       -C cache
              Use cache instead of /etc/ld.so.cache.

       -r root
              Change to and use root as the root directory.

       -l     Library mode.  Manually link individual  libraries.
              Intended for use by experts only.

       -p --print-cache
              Print   the  lists  of  directories  and  candidate
              libraries stored in the current cache.

       -c --format=FORMAT
              Use FORMAT for the cache file. Choices are old, new
              and compat (the default).

       -? --help --usage
              Print usage information.

       -V --version
              Print version and exit.

EXAMPLES
       In the bootup file /etc/rc having the line

              /sbin/ldconfig -v

       will  set up the correct links for the shared binaries and
       rebuild the cache.

       On the command line

              # /sbin/ldconfig -n /lib

       as root after the installation of a new DLL, will properly
       update the shared library symbolic links in /lib.


FILES
       /lib/ld.so, /lib/ld-linux.so.*
                           execution time linker/loader
       /etc/ld.so.conf     File   containing  a  list  of  colon,
                           space,   tab,   newline,   or    comma
                           spearated   directories  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.   This
                           file  is not in human readable format,
                           and is not intended to be edited.
       lib*.so.version     shared libraries

SEE ALSO
       ldd(d), ld.so(o).

BUGS
       ldconfig's functionality, in conjunction  with  ld.so,  is
       only available for executables compiled using libc version
       4.4.3 or greater.

       ldconfig, being a user process, must be run  manually  and
       has  no  means  of  dynamically  determining and relinking
       shared libraries for use  by  ld.so  when  a  new  DLL  is
       installed.

AUTHORS
       David Engel and Mitch D'Souza.



                        30 September 2000             ldconfig(g)