path: root/sbin/ldconfig/ldconfig.8
diff options
Diffstat (limited to 'sbin/ldconfig/ldconfig.8')
1 files changed, 98 insertions, 0 deletions
diff --git a/sbin/ldconfig/ldconfig.8 b/sbin/ldconfig/ldconfig.8
new file mode 100644
index 000000000000..e363269baab4
--- /dev/null
+++ b/sbin/ldconfig/ldconfig.8
@@ -0,0 +1,98 @@
+.Dd October 3, 1993
+.Os NetBSD 0.9
+.Nm ldconfig
+.Nd configure the shared library cache
+.Nm ldconfig
+.Op Fl rsv
+.Op Ar directory Ar ...
+is used to prepare a set of
+.Dq hints
+for use by the run-time linker
+.Xr ld.so
+to facilitate quick lookup of shared libraries available in multiple
+directories. It scans a set of built-in system directories and any
+.Ar directories
+specified on the command line (in the given order) looking for shared
+libraries and stores the results in the file
+.Xr /var/run/ld.so.hints
+to forstall the overhead that would otherwise result from the
+directory search operations
+.Xr ld.so
+would have to perform to load the required shared libraries.
+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.
+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.
+is a
+.Sq \:
+separated list of directory paths which are searched by
+.Xr 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
+.Xr ld.
+.Nm Ldconfig
+is typically run as part of the boot sequence.
+The following options recognized by
+.Nm ldconfig:
+.Bl -tag -width indent
+.It Fl r
+Lists the current contents of
+.Xr ld.so.hints
+on the standard output. The hints file will not be modified.
+.It Fl s
+Do not scan
+.Nm ldconfig
+'s builtin system directories
+.Sq /usr/lib
+.Sq /usr/local/lib
+for shared libraries.
+.It Fl v
+Switch on verbose mode.
+.Sh Security
+Special care must be taken when loading shared libraries into the address
+space of
+.Ev set-user-Id
+programs. Whenever such a program is run,
+.Xr ld.so
+will only load shared libraries from the
+.Ev ld.so.hints
+file. In particular, the
+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 ldconfig
+are under control of the system's administrator.
+.Xr ld.so
+further assists set-user-Id programs by erasing the
+from the environment.
+.Xr /var/run/ld.so.hints
+.Xr ld 1 ,
+.Xr link 5
+utility first appeared in SunOS 4.0, it appeared in its current form
+in NetBSD 0.9a.