2 .\" Copyright (c) 1993 Paul Kranenburg
3 .\" All rights reserved.
4 .\" Copyright (c) 2021 The FreeBSD Foundation, Inc.
6 .\" Portions of this documentation were written by
7 .\" Konstantin Belousov <kib@FreeBSD.org> under sponsorship
8 .\" from the FreeBSD Foundation.
10 .\" Redistribution and use in source and binary forms, with or without
11 .\" modification, are permitted provided that the following conditions
13 .\" 1. Redistributions of source code must retain the above copyright
14 .\" notice, this list of conditions and the following disclaimer.
15 .\" 2. Redistributions in binary form must reproduce the above copyright
16 .\" notice, this list of conditions and the following disclaimer in the
17 .\" documentation and/or other materials provided with the distribution.
18 .\" 3. All advertising materials mentioning features or use of this software
19 .\" must display the following acknowledgement:
20 .\" This product includes software developed by Paul Kranenburg.
21 .\" 3. The name of the author may not be used to endorse or promote products
22 .\" derived from this software without specific prior written permission
24 .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25 .\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26 .\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27 .\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28 .\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29 .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30 .\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31 .\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
40 .Nd configure the dynamic linker search path for shared libraries
45 .Op Fl f Ar hints_file
49 utility is used to configure the set of paths used by the dynamic linker
51 when searching for shared libraries.
52 The dynamic linker looks for libraries in a set of built-in system directories
53 and any directories specified in the hints file.
54 This obviates the need for storing search paths within the executable,
57 option for the static linker
60 The hints file is maintained by
64 list to be stored in the hints file is supplied on the command line.
68 list on the command line,
70 may be specified; these are expected to contain directories
71 to scan for shared libraries.
72 Each directory's pathname must start on a new
74 Blank lines and lines starting with the comment character
78 For security reasons, directories which are world or group-writable or which
79 are not owned by root produce warning messages and are skipped, unless
86 environment variable can be used to specify additional
87 shared library search directories.
91 separated list of directory paths which are searched by
93 when it needs to load a shared library.
94 It can be viewed as the run-time
100 The following options are recognized by
102 .Bl -tag -width indent
104 Generate the hints for 32-bit ABI shared libraries
105 on 64-bit systems that support running 32-bit binaries.
107 Ignored for backwards compatibility.
109 Force writing big-endian binary data to the hints file.
110 The default is to create hints files in the native byte-order of the host.
111 Reading of and merging into hints files preserves the endianness of the
114 Appends pathnames on the command line to the directory list from
117 This is the default action when no options are given.
118 .It Fl f Ar hints_file
119 Read and/or update the specified hints file, instead of the standard file.
120 This option is provided primarily for testing.
122 Run in insecure mode.
123 The security checks will not be performed.
125 Instead of replacing the list of the directories to search with the
126 directories specified on the command line, merge existing list
127 with the specified directories, and write the result to the hints file.
129 List the current list of the directories from the hints file
130 on the standard output.
131 The hints file is not modified.
133 Scan and print all libraries found on the directories list.
141 are accepted but ignored.
143 Special care must be taken when loading shared libraries into the address
147 Whenever such a program is run by any user except the owner of the program,
148 the dynamic linker will only load shared libraries from paths found in
152 is not used to search for libraries.
155 serves to specify the trusted collection of directories from which
156 shared objects can be safely loaded.
158 .Bl -tag -width /usr/local/libdata/ldconfig/* -compact
159 .It Pa /var/run/ld-elf.so.hints
160 Standard hints file for the ELF dynamic linker.
161 .It Pa /var/run/ld-elf32.so.hints
162 Hints file for 32 bit libraries on 64 bit architectures, processed by
163 ldconfig when invoked with
165 .It Pa /etc/ld-elf.so.conf
166 Optional file with names of directories to be included in the standard
167 hints file when booting to multi-user mode.
168 .It Pa /usr/local/libdata/ldconfig/*
169 Additional files with names of directories provided by optional ports
179 utility first appeared in SunOS 4.0, it appeared in its current form
183 The name 'hints file' is historic from the times when the file also contained
184 hints to the dynamic linker.
185 This functionality is not provided for ELF.