Name
uselib — load shared library
Synopsis
#include <unistd.h>
int
uselib( |
const char *library); |
![[Note]](../stylesheet/note.png) |
Note |
|---|---|
| No declaration of this system call is provided in glibc headers; see NOTES. |
DESCRIPTION
The system call uselib()
serves to load a shared library to be used by the calling
process. It is given a pathname. The address where to load is
found in the library itself. The library can have any
recognized binary format.
RETURN VALUE
On success, zero is returned. On error, −1 is
returned, and errno is set
appropriately.
ERRORS
In addition to all of the error codes returned by open(2) and mmap(2), the following may also be returned:
- EACCES
-
The library specified by
librarydoes not have read or execute permission, or the caller does not have search permission for one of the directories in the path prefix. (See also path_resolution(7).) - ENFILE
-
The system-wide limit on the total number of open files has been reached.
- ENOEXEC
-
The file specified by
libraryis not an executable of a known type; for example, it does not have the correct magic numbers.
CONFORMING TO
uselib() is Linux-specific,
and should not be used in programs intended to be
portable.
NOTES
This obsolete system call is not supported by glibc. No declaration is provided in glibc headers, but, through a quirk of history, glibc versions before 2.23 did export an ABI for this system call. Therefore, in order to employ this system call, it was sufficient to manually declare the interface in your code; alternatively, you could invoke the system call using syscall(2).
In ancient libc versions, uselib() was used to load the shared
libraries with names found in an array of names in the
binary.
Since libc 4.3.2, startup code tries to prefix these names
with "/usr/lib", "/lib" and "" before giving up. In libc
4.3.4 and later these names are looked for in the directories
found in LD_LIBRARY_PATH, and
if not found there, prefixes "/usr/lib", "/lib" and "/" are
tried.
From libc 4.4.4 on only the library "/lib/ld.so" is loaded, so that this dynamic library can load the remaining libraries needed (again using this call). This is also the state of affairs in libc5.
glibc2 does not use this call.
Since Linux 3.15, this system call is available only when
the kernel is configured with the CONFIG_USELIB option.
COLOPHON
This page is part of release 4.07 of the Linux man-pages project. A
description of the project, information about reporting bugs,
and the latest version of this page, can be found at
https://www.kernel.org/doc/man−pages/.
|
Copyright (c) 1992 Drew Eckhardt (drewcs.colorado.edu), March 28, 1992 %%%LICENSE_START(VERBATIM) Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date. The author(s) assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. The author(s) may not have taken the same level of care in the production of this manual, which is licensed free of charge, as they might when working professionally. Formatted or processed versions of this manual, if unaccompanied by the source, must acknowledge the copyright and authors of this work. %%%LICENSE_END Modified by Michael Haardt <michaelmoria.de> Modified 1993-07-24 by Rik Faith <faithcs.unc.edu> Modified 1996-10-22 by Eric S. Raymond <esrthyrsus.com> Modified 2004-06-23 by Michael Kerrisk <mtk.manpagesgmail.com> Modified 2005-01-09 by aeb |