uselib - load shared library
#include <unistd.h>
[[deprecated]] int uselib(const char *library);
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.
On success, zero is returned. On error, -1 is returned, and
errno is set
to indicate the error.
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 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).)
- ENFILE
- The system-wide limit on the total number of open files has
been reached.
- ENOEXEC
- 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 portable.
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
syscall(2).
In ancient libc versions (before glibc 2.0),
uselib() was used to load
the shared libraries with names found in an array of names in the binary.
Since Linux 3.15, this system call is available only when the kernel is
configured with the
CONFIG_USELIB option.
ar(1),
gcc(1),
ld(1),
ldd(1),
mmap(2),
open(2),
dlopen(3),
capabilities(7),
ld.so(8)