MAN page from Mandriva 2009 glibc-2.9-0.20081113.5.3mnb2.i586.rpm
Section: Maintenance Commands (8)
Updated: 30 September 2000Index
ldconfig - determine run-time link bindings
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 specifiedon the command line, in the file/etc/ld.so.conf
,and in the trusted directories(/usr/lib
checks the header and file names of the libraries it encounters whendetermining which versions should have their links updated.ldconfig
ignores symbolic links when scanning for libraries.
ldconfigwill 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 whenmaking dynamic libraries, it is wise to explicitly link against libc (use -lc).
Some existing libs do not contain enough information to allow the deduction oftheir type, therefore the/etc/ld.so.conffile format allows the specification of an expected type. This isonlyused for those ELF libs which we can not work out. The formatis like this "dirname=TYPE", where type can be libc4, libc5 or libc6.(This syntax also works on the command line). Spaces arenotallowed. Also see the-poption.
Directory names containing an=are no longer legal unless they also have an expected type specifier.
ldconfigshould normally be run by the super-user as it may require writepermission on some root owned directories and files.It is normally run automatically at bootup, from /etc/rc, or manuallywhenever new DLL's are installed.
- -v --verbose
- Verbose mode.Print current version number, the name of each directory as itis scanned and any links that are created.
- Only process directories specified on the command line.Don't process the trusted directories(/usr/liband/lib)nor those specified in/etc/ld.so.conf.Implies-N.
- Don't rebuild the cache.Unless-Xis also specified, links are still updated.
- Don't update links.Unless-Nis also specified, the cache is still rebuilt.
- -f conf
- Useconfinstead of/etc/ld.so.conf.
- -C cache
- Usecacheinstead of/etc/ld.so.cache.
- -r root
- Change to and userootas the root directory.
- Library mode.Manually link individual libraries.Intended for use by experts only.
- -p --print-cache
- Print the lists of directories and candidate libraries stored inthe current cache.
- -c --format=FORMAT
- UseFORMATfor the cache file. Choices are old, new and compat (the default).
- -? --help --usage
- Print usage information.
- -V --version
- Print version and exit.
In the bootup file/etc/rc
having the line
will set up the correct links for the shared binaries and rebuildthe cache.
- On the command line
as root after the installation of a new DLL, will properly update theshared library symbolic links in /lib.
# /sbin/ldconfig -n /lib
- /lib/ld.so, /lib/ld-linux.so.*
- execution time linker/loader
- File containing a list of colon, space, tab, newline, or comma spearateddirectories in which to search for libraries.
- File containing an ordered list of libraries found in the directoriesspecified in/etc/ld.so.conf.This file is not in human readable format, and is not intended to beedited.
- shared libraries
ldconfig'sfunctionality, in conjunction withld.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 dynamicallydetermining and relinking shared libraries for use byld.sowhen a new DLL is installed.
David Engel and Mitch D'Souza.
- SEE ALSO
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