.\" Copyright (c) 1992 Drew Eckhardt (drew@cs.colorado.edu), March 28, 1992 .\" .\" SPDX-License-Identifier: Linux-man-pages-copyleft .\" .\" Modified by Michael Haardt .\" Modified 1993-07-24 by Rik Faith .\" Modified 1996-10-22 by Eric S. Raymond .\" Modified 2004-06-23 by Michael Kerrisk .\" Modified 2005-01-09 by aeb .\" .TH uselib 2 2023-10-31 "Linux man-pages 6.7" .SH NAME uselib \- load shared library .SH SYNOPSIS .nf .B #include .P .BI "[[deprecated]] int uselib(const char *" library ); .fi .SH DESCRIPTION The system call .BR 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. .SH RETURN VALUE On success, zero is returned. On error, \-1 is returned, and .I errno is set to indicate the error. .SH ERRORS In addition to all of the error codes returned by .BR open (2) and .BR mmap (2), the following may also be returned: .TP .B EACCES The library specified by .I 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 .BR path_resolution (7).) .TP .B ENFILE The system-wide limit on the total number of open files has been reached. .TP .B ENOEXEC The file specified by .I library is not an executable of a known type; for example, it does not have the correct magic numbers. .SH STANDARDS Linux. .SH HISTORY This obsolete system call is not supported by glibc. No declaration is provided in glibc headers, but, through a quirk of history, glibc before glibc 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 .BR syscall (2). .P In ancient libc versions (before glibc 2.0), .BR uselib () was used to load the shared libraries with names found in an array of names in the binary. .\" .P .\" .\" libc 4.3.1f - changelog 1993-03-02 .\" Since libc 4.3.2, startup code tries to prefix these names .\" with "/usr/lib", "/lib" and "" before giving up. .\" .\" libc 4.3.4 - changelog 1993-04-21 .\" In libc 4.3.4 and later these names are looked for in the directories .\" found in .\" .BR LD_LIBRARY_PATH , .\" and if not found there, .\" prefixes "/usr/lib", "/lib" and "/" are tried. .\" .P .\" 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. .\" .P .\" glibc2 does not use this call. .P Since Linux 3.15, .\" commit 69369a7003735d0d8ef22097e27a55a8bad9557a this system call is available only when the kernel is configured with the .B CONFIG_USELIB option. .SH SEE ALSO .BR ar (1), .BR gcc (1), .BR ld (1), .BR ldd (1), .BR mmap (2), .BR open (2), .BR dlopen (3), .BR capabilities (7), .BR ld.so (8)