2 .\" Copyright (c) 1993 Paul Kranenburg
3 .\" All rights reserved.
5 .\" Redistribution and use in source and binary forms, with or without
6 .\" modification, are permitted provided that the following conditions
8 .\" 1. Redistributions of source code must retain the above copyright
9 .\" notice, this list of conditions and the following disclaimer.
10 .\" 2. Redistributions in binary form must reproduce the above copyright
11 .\" notice, this list of conditions and the following disclaimer in the
12 .\" documentation and/or other materials provided with the distribution.
13 .\" 3. All advertising materials mentioning features or use of this software
14 .\" must display the following acknowledgement:
15 .\" This product includes software developed by Paul Kranenburg.
16 .\" 3. The name of the author may not be used to endorse or promote products
17 .\" derived from this software without specific prior written permission
19 .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 .\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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28 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
37 .Nd configure the shared library cache
42 .Op Fl f Ar hints_file
43 .Op Ar directory | file Ar ...
46 is used to prepare a set of
48 for use by the dynamic linker
49 to facilitate quick lookup of shared libraries available in multiple
50 directories. It scans a set of built-in system directories and any
52 specified on the command line (in the given order) looking for
53 shared libraries and stores the results in a system file to forestall
54 the overhead that would otherwise result from the directory search
55 operations the dynamic linker would have to perform to load the
56 required shared libraries.
58 Files named on the command line are expected to contain directories
59 to scan for shared libraries. Each directory's pathname must start on a new
60 line. Blank lines and lines starting with the comment character
64 The shared libraries so found will be automatically available for loading
65 if needed by the program being prepared for execution.
66 This obviates the need
67 for storing search paths within the executable.
71 environment variable can be used to override the use of
72 directories (or the order thereof) from the cache or to specify additional
73 directories where shared libraries might be found.
77 separated list of directory paths which are searched by
79 when it needs to load a shared library.
80 It can be viewed as the run-time
87 is typically run as part of the boot sequence.
89 The following options recognized by
91 .Bl -tag -width indent
93 Generate the hints for a.out format shared libraries.
95 Generate the hints for ELF format shared libraries.
97 Rescan the previously configured directories. This opens the previous hints
98 file and fetches the directory list from the header. Any additional pathnames
99 on the command line are also processed.
100 .It Fl f Ar hints_file
101 Read and/or update the specified hints file, instead of the standard file.
102 This option is provided primarily for testing.
104 Instead of replacing the contents of the hints file
105 with those found in the directories specified,
108 Directories recorded in the hints file by previous runs of
110 are also rescanned for new shared libraries.
112 List the current contents of the hints file
113 on the standard output.
114 The hints file is not modified. The list of
115 directories stored in the hints file is included.
117 Do not scan the built-in system directory
119 for shared libraries.
121 Switch on verbose mode.
123 Special care must be taken when loading shared libraries into the address
127 Whenever such a program is run,
129 will only load shared libraries from the hints
133 is not used to search for libraries.
134 Thus, the role of ldconfig is dual.
136 addition to building a set of hints for quick lookup, it also serves to
137 specify the trusted collection of directories from which shared objects can
139 It is presumed that the set of directories specified to
141 are under control of the system's administrator.
143 .Bl -tag -width OBJFORMATxxx -compact
147 (see below) to determine whether
151 is the default. If set, its value should be either
157 .Bl -tag -width /var/run/ld-elf.so.hintsxxx -compact
158 .It Pa /var/run/ld.so.hints
159 Standard hints file for the a.out dynamic linker.
160 .It Pa /var/run/ld-elf.so.hints
161 Standard hints file for the ELF dynamic linker.
162 .It Pa /etc/ld.so.conf
163 Conventional configuration file containing directory names for
166 .It Pa /etc/ld-elf.so.conf
167 Conventional configuration file containing directory names for
170 .It Pa /etc/objformat
175 is the default. If present, it must consist of a single line
186 utility first appeared in SunOS 4.0, it appeared in its current form