uselib — load shared library
||const char *library
|No declaration of this system call is provided in glibc headers; see NOTES.|
The system call
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.
On success, zero is returned. On error, −1 is
errno is set
The library specified by
library does 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).)
The system-wide limit on the total number of open files has been reached.
The file specified by
library is not an
executable of a known type; for example, it does not
have the correct magic numbers.
uselib() is Linux-specific,
and should not be used in programs intended to be
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
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
if not found there, prefixes "/usr/lib", "/lib" and "/" are
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
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
Copyright (c) 1992 Drew Eckhardt (drewcs.colorado.edu), March 28, 1992
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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