3.9. /lib : Essential shared libraries and kernel modules

3.9.1. Purpose

The /lib directory contains those shared library images needed to boot the system and run the commands in the root filesystem, ie. by binaries in /bin and /sbin. [11]

3.9.2. Requirements

At least one of each of the following filename patterns are required (they may be files, or symbolic links):

libc.so.*The dynamically-linked C library (optional)
ld*The execution time linker/loader (optional)

If a C preprocessor is installed, /lib/cpp must be a reference to it, for historical reasons. [12]

3.9.3. Specific Options

The following directories, or symbolic links to directories, must be in /lib, if the corresponding subsystem is installed:

modulesLoadable kernel modules (optional)

[11] Shared libraries that are only necessary for binaries in /usr (such as any X Window binaries) must not be in /lib. Only the shared libraries required to run binaries in /bin and /sbin may be here. In particular, the library libm.so.* may also be placed in /usr/lib if it is not required by anything in /bin or /sbin.

[12] The usual placement of this binary is /usr/bin/cpp.