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LDCONFIG(8)		    System Manager's Manual		   LDCONFIG(8)

NAME
       ldconfig	 --  configure	the  dynamic linker search path	for shared li-
       braries

SYNOPSIS
       ldconfig	[-32] [-BRimr] [-f hints_file] [directory | file ...]

DESCRIPTION
       ldconfig	utility	is used	to configure the set of	paths used by the  dy-
       namic  linker  ld-elf.so.1(1) when searching for	shared libraries.  The
       dynamic linker looks for	libraries in a set of built-in system directo-
       ries and	any directories	specified in the hints	file.	This  obviates
       the need	for storing search paths within	the executable,	see the	-rpath
       option for the static linker ld(1).

       The  hints  file	is maintained by ldconfig.  The	directories list to be
       stored in the hints file	is supplied on the command line.

       Alternatively to	the directories	list on	the command line, files	may be
       specified; these	are expected to	contain	directories to scan for	shared
       libraries.  Each	directory's pathname must start	on a new line.	 Blank
       lines and lines starting	with the comment character `#' are ignored.

       For  security reasons, directories which	are world or group-writable or
       which are not owned by root produce warning messages and	 are  skipped,
       unless the -i option is present.

       The  LD_LIBRARY_PATH  environment variable can be used to specify addi-
       tional shared library search directories.   LD_LIBRARY_PATH  is	a  `:'
       separated  list	of  directory  paths which are searched	by the dynamic
       linker when it needs to load a shared library.  It can be viewed	as the
       run-time	equivalent of the -L switch of ld(1).

       The following options are recognized by ldconfig:

       -32     Generate	the hints for 32-bit ABI shared	 libraries  on	64-bit
	       systems that support running 32-bit binaries.

       -elf    Ignored for backwards compatibility.

       -B      Force  writing  big-endian  binary data to the hints file.  The
	       default is to create hints files	in the	native	byte-order  of
	       the  host.   Reading  of	and merging into hints files preserves
	       the endianness of the existing hints file.

       -R      Appends pathnames on the	command	line  to  the  directory  list
	       from the	hints file.

	       This is the default action when no options are given.

       -f hints_file
	       Read  and/or  update  the  specified hints file,	instead	of the
	       standard	file.  This option is provided primarily for testing.

       -i      Run in insecure mode.  The security checks  will	 not  be  per-
	       formed.

       -m      Instead of replacing the	list of	the directories	to search with
	       the  directories	 specified on the command line,	merge existing
	       list with the specified directories, and	write  the  result  to
	       the hints file.

       -r      List the	current	list of	the directories	from the hints file on
	       the standard output.  The hints file is not modified.

	       Scan and	print all libraries found on the directories list.

       The historic options -elf, -s, and -v are accepted but ignored.

SECURITY
       Special	care  must be taken when loading shared	libraries into the ad-
       dress space of set-user-Id programs.  Whenever such a program is	run by
       any user	except the owner of the	program, the dynamic linker will  only
       load  shared libraries from paths found in the hints file.  In particu-
       lar, the	LD_LIBRARY_PATH	is not used to search  for  libraries.	 Thus,
       ldconfig	 serves	 to specify the	trusted	collection of directories from
       which shared objects can	be safely loaded.

FILES
       /var/run/ld-elf.so.hints	      Standard hints file for the ELF  dynamic
				      linker.
       /var/run/ld-elf32.so.hints     Hints  file  for	32 bit libraries on 64
				      bit architectures, processed by ldconfig
				      when invoked with	-32.
       /etc/ld-elf.so.conf	      Optional file with names of  directories
				      to  be  included	in  the	standard hints
				      file when	booting	to multi-user mode.
       /usr/local/libdata/ldconfig/*  Additional files with names of  directo-
				      ries provided by optional	ports or pack-
				      ages.

SEE ALSO
       ld(1), ld-elf.so.1(1), link(5)

HISTORY
       A ldconfig utility first	appeared in SunOS 4.0, it appeared in its cur-
       rent form in FreeBSD 1.1.

       The  name  'hints  file'	 is historic from the times when the file also
       contained hints to the dynamic linker.  This functionality is not  pro-
       vided for ELF.

FreeBSD	13.2		       February	28, 2024		   LDCONFIG(8)

NAME | SYNOPSIS | DESCRIPTION | SECURITY | FILES | SEE ALSO | HISTORY

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