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
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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
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37 .Nd configure the shared library cache
43 .Op Fl f Ar hints_file
48 utility is used to prepare a set of
50 for use by the dynamic linker
51 to facilitate quick lookup of shared libraries available in multiple
53 It scans a set of built-in system directories and any
55 specified on the command line (in the given order) looking for
56 shared libraries and stores the results in a system file to forestall
57 the overhead that would otherwise result from the directory search
58 operations the dynamic linker would have to perform to load the
59 required shared libraries.
61 Files named on the command line are expected to contain directories
62 to scan for shared libraries.
63 Each directory's pathname must start on a new
65 Blank lines and lines starting with the comment character
68 Filenames must conform to the
70 pattern in order to be added to the hints file.
72 For security reasons, directories which are world or group-writable or which
73 are not owned by root produce warning messages and are skipped, unless
78 The shared libraries which are found will be automatically available for loading
79 if needed by the program being prepared for execution.
80 This obviates the need
81 for storing search paths within the executable.
85 environment variable can be used to override the use of
86 directories (or the order thereof) from the cache or to specify additional
87 directories where shared libraries might be found.
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
102 utility is typically run as part of the boot sequence.
104 The following options are recognized by
106 .Bl -tag -width indent
108 Generate the hints for 32-bit ABI shared libraries
109 on 64-bit systems that support running 32-bit binaries.
111 Generate the hints for a.out format shared libraries.
113 Generate the hints for ELF format shared libraries.
115 Rescan the previously configured directories.
116 This opens the previous hints
117 file and fetches the directory list from the header.
118 Any additional pathnames
119 on the command line are also processed.
120 This is the default action when no parameters are given.
121 .It Fl f Ar hints_file
122 Read and/or update the specified hints file, instead of the standard file.
123 This option is provided primarily for testing.
125 Run in insecure mode.
126 The security checks will not be performed.
128 Instead of replacing the contents of the hints file
129 with those found in the directories specified,
132 Directories recorded in the hints file by previous runs of
134 are also rescanned for new shared libraries.
136 List the current contents of the hints file
137 on the standard output.
138 The hints file is not modified.
140 directories stored in the hints file is included.
142 Do not scan the built-in system directory
144 for shared libraries.
146 Switch on verbose mode.
149 Special care must be taken when loading shared libraries into the address
153 Whenever such a program is run by any user except the owner of the program,
155 will only load shared libraries from the hints
159 is not used to search for libraries.
160 Thus, the role of ldconfig is dual.
162 addition to building a set of hints for quick lookup, it also serves to
163 specify the trusted collection of directories from which shared objects can
166 .Bl -tag -width OBJFORMATxxx -compact
170 (see below) to determine whether
175 If set, its value should be either
181 .Bl -tag -width /var/run/ld-elf.so.hintsxxx -compact
182 .It Pa /var/run/ld.so.hints
183 Standard hints file for the a.out dynamic linker.
184 .It Pa /var/run/ld-elf.so.hints
185 Standard hints file for the ELF dynamic linker.
186 .It Pa /etc/ld.so.conf
187 Conventional configuration file containing directory names for
190 .It Pa /etc/ld-elf.so.conf
191 Conventional configuration file containing directory names for
194 .It Pa /var/run/ld-elf32.so.hints
195 .It Pa /var/run/ld32.so.hints
196 Conventional configuration files containing directory names for
199 .It Pa /etc/objformat
205 If present, it must consist of a single line
217 utility first appeared in SunOS 4.0, it appeared in its current form
221 Some security checks (for example, verifying root ownership of
222 added directories) are not performed when