uselib — load shared library
#include <unistd.h>
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
appropriately.
In addition to all of the error codes returned by open(2) and mmap(2), the following may also be returned:
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 limit on the total number of open files has been reached.
The file specified by library
is not an
executable of known type, e.g., does not have the
correct magic numbers.
uselib
() is Linux specific,
and should not be used in programs intended to be
portable.
uselib
() was used by early
libc startup code 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.
ar(1), gcc(1), ld(1), ldd(1), mmap(2), open(2), dlopen(3), capability(7), ld.so(8)
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