USELIB(2)                           Linux Programmer's Manual                           USELIB(2)



NAME
       uselib - load shared library

SYNOPSIS
       #include <unistd.h>

       int uselib(const char *library);

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 library does not have read or execute permission,  or  the
              caller  does not have search permission for one of the directories in the path pre‐
              fix.  (See also path_resolution(7).)

       ENFILE The system 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.

CONFORMING TO
       uselib() is Linux-specific, and should not be used in programs intended to be portable.

NOTES
       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.

SEE ALSO
       ar(1), gcc(1), ld(1), ldd(1), mmap(2), open(2), dlopen(3), capabilities(7), ld.so(8)

COLOPHON
       This  page  is  part of release 3.74 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 http://www.kernel.org/doc/man-pages/.



Linux                                       2005-01-09                                  USELIB(2)