172 lines
5.3 KiB
Groff
172 lines
5.3 KiB
Groff
.\" $NetBSD: ldconfig.8,v 1.14 2002/10/01 13:40:34 wiz Exp $
|
|
.\"
|
|
.\" Copyright (c) 1998 The NetBSD Foundation, Inc.
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" This code is derived from software contributed to The NetBSD Foundation
|
|
.\" by Paul Kranenburg.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the NetBSD
|
|
.\" Foundation, Inc. and its contributors.
|
|
.\" 4. Neither the name of The NetBSD Foundation nor the names of its
|
|
.\" contributors may be used to endorse or promote products derived
|
|
.\" from this software without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
|
|
.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
|
|
.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
|
.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
|
|
.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
.\" POSSIBILITY OF SUCH DAMAGE.
|
|
.\"
|
|
.Dd October 8, 2000
|
|
.Dt LDCONFIG 8
|
|
.Os
|
|
.Sh NAME
|
|
.Nm ldconfig
|
|
.Nd configure the a.out shared library cache
|
|
.Sh SYNOPSIS
|
|
.Nm ldconfig
|
|
.Op Fl cmrsSv
|
|
.Op Ar directory Ar ...
|
|
.Sh DESCRIPTION
|
|
.Nm
|
|
is used to prepare a set of
|
|
.Dq hints
|
|
for use by the a.out run-time linker
|
|
.Nm ld.so
|
|
to facilitate quick lookup of shared libraries available in multiple
|
|
directories.
|
|
.Nm
|
|
is only available on systems that use the
|
|
.Dq a.out
|
|
format for executables and libraries \(en on ELF systems, all the work
|
|
is done by
|
|
.Nm ld.elf_so .
|
|
.Pp
|
|
By default, it scans a set of built-in system directories,
|
|
directories listed in
|
|
.Pa /etc/ld.so.conf ,
|
|
and any
|
|
.Ar directories
|
|
specified on the command line (in the given order) looking for shared
|
|
libraries and stores the results in the file
|
|
.Pa /var/run/ld.so.hints
|
|
to forestall the overhead that would otherwise result from the
|
|
directory search operations
|
|
.Nm ld.so
|
|
would have to perform to load required shared libraries.
|
|
.Pp
|
|
The shared libraries so found will be automatically available for loading
|
|
if needed by the program being prepared for execution.
|
|
This obviates the need for storing search paths within the executable.
|
|
.Pp
|
|
The
|
|
.Ev LD_LIBRARY_PATH
|
|
environment variable can be used to override the use of
|
|
directories (or the order thereof) from the cache or to specify additional
|
|
directories where shared libraries might be found.
|
|
.Ev LD_LIBRARY_PATH
|
|
is a
|
|
.Sq \&:
|
|
separated list of directory paths that are searched by
|
|
.Nm ld.so
|
|
when it needs to load a shared library.
|
|
It can be viewed as the run-time equivalent of the
|
|
.Fl L
|
|
switch of
|
|
.Nm ld .
|
|
.Pp
|
|
.Nm
|
|
is typically run as part of the boot sequence.
|
|
.Pp
|
|
The following options are recognized by
|
|
.Nm ldconfig :
|
|
.Bl -tag -width indent
|
|
.It Fl c
|
|
Do not scan directories listed in
|
|
.Pa /etc/ld.so.conf
|
|
for shared libraries.
|
|
.It Fl m
|
|
Merge the result of the scan of the directories given as arguments into
|
|
the existing hints file.
|
|
The default action is to build the hints file afresh.
|
|
.It Fl r
|
|
Lists the current contents of
|
|
.Pa ld.so.hints
|
|
on the standard output.
|
|
The hints file will not be modified.
|
|
.It Fl s
|
|
Do not scan the built-in system directory
|
|
.Pq Pa /usr/lib ,
|
|
nor any directories listed in
|
|
.Pa /etc/ld.so.conf
|
|
for shared libraries.
|
|
.It Fl S
|
|
Do not scan the built-in system directory
|
|
.Pq Pa /usr/lib ,
|
|
for shared libraries.
|
|
(Directories listed in
|
|
.Pa /etc/ld.so.conf
|
|
are still scanned.)
|
|
.It Fl v
|
|
Switch on verbose mode.
|
|
.El
|
|
.Sh FILES
|
|
.Pa /var/run/ld.so.hints ,
|
|
.Pa /etc/ld.so.conf
|
|
.Sh SEE ALSO
|
|
.Xr ld 1 ,
|
|
.Xr ld.so 1 ,
|
|
.Xr ld.so.conf 5 ,
|
|
.Xr link 5
|
|
.Sh HISTORY
|
|
A
|
|
.Nm
|
|
utility first appeared in SunOS 4.0, it appeared in its current form
|
|
in
|
|
.Nx 0.9a .
|
|
.Sh SECURITY CONSIDERATIONS
|
|
Special care must be taken when loading shared libraries into the address
|
|
space of
|
|
.Em set-user-ID
|
|
programs.
|
|
Whenever such a program is run,
|
|
.Nm ld.so
|
|
will only load shared libraries from the
|
|
.Pa ld.so.hints
|
|
file.
|
|
In particular, the
|
|
.Ev LD_LIBRARY_PATH
|
|
and
|
|
.Ev LD_PRELOAD
|
|
is not used to search for libraries.
|
|
Thus, the role of ldconfig is dual.
|
|
In addition to building a set of hints for quick lookup, it also serves to
|
|
specify the trusted collection of directories from which shared objects can
|
|
be safely loaded.
|
|
It is presumed that the set of directories specified to
|
|
.Nm
|
|
is under control of the system's administrator.
|
|
.Nm ld.so
|
|
further assists set-user-ID programs by erasing the
|
|
.Ev LD_LIBRARY_PATH
|
|
and
|
|
.Ev LD_PRELOAD
|
|
from the environment.
|