updateprebinding(1)      BSD General Commands Manual     updateprebinding(1)

NAME
     updateprebinding -- Update prebinding information when new system
     libraries or frameworks are installed

SYNOPSIS
     updateprebinding [-root directory] [-force] [-debug]

DESCRIPTION
     updateprebinding ensures that prebinding information is up-to-date after
     new versions of system libraries are installed.  Prebinding information
     is pre-calculated address information for libraries used by a given
     library.  By pre-determining where a function in another library is des-
     tined to be placed, the dynamic linker does not have to resolve symbols
     at application startup time, and the application can launch faster.

     Because each recompilation of a library may place functions at different
     addresses, a newly installed library's prebinding information might not
     match the libraries already on the disk.  When the dynamic linker deter-
     mines that prebinding information for a library could be invalid, it
     defaults to resolving all the names for that library, and for all
     libraries referenced by that library, losing any advantage of having the
     prebinding information.

     The -root option specifies the directory tree to search for changed
     files.  This is usually the root directory.  updateprebinding will look
     for dependent libraries within this directory hierarchy, but will not go
     to different file systems.  The argument allows you to update prebinding
     information for a specific file to match a non-running version of the
     operating system on another partition.  updateprebinding uses the root
     to find the system libraries for that version of the OS.  The root argu-
     ment is not intended to limit updateprebinding's effect to a particular
     set of libraries.  By default, updateprebinding only changes a file if
     the prebinding is out of date.

     The -force option ensures that all files examined are re-prebound, even
     if the prebinding is otherwise up-to-date.  The command updateprebinding
     -root / -force will prebind all binaries on the root volume, even if oth-
     erwise correct.

     The -debug option prints out additional information while the prebinding
     is being updated.

Issues
     updateprebinding only work on libraries that have been compiled and
     linked with the prebinding information added.  Applications still gain
     the benefits of prebinding as long as the system libraries used by the
     application have been correctly prebound.

     Updating prebinding for a given library can fail if any of its dependent
     libraries are invalid -- not prebound, expected load address conflicting
     with other loaded libraries, or missing architecture in a universal
     library.  To test if an application is able to use prebinding informa-
     tion, set the environment variable DYLDPREBINDEBUG.  (See dyld(1) for
     details on this option.)

SEE ALSO
     dyld(1)

BSD                            February 14, 2001                           BSD