uselib(2) System Calls Manual uselib(2) uselib - #include [[deprecated]] int uselib(const char *library); uselib() . . . . On success, zero is returned. On error, -1 is returned, and errno is set to indicate the error. , open(2) mmap(2), : EACCES , library, , , . ( path_resolution(7).) ENFILE . ENOEXEC , library, ; , (magic numbers). Linux. 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. Linux 3.15 , CONFIG_USELIB. . ar(1), gcc(1), ld(1), ldd(1), mmap(2), open(2), dlopen(3), capabilities(7), ld.so(8) Azamat Hackimov , Dmitriy Ovchinnikov , Dmitry Bolkhovskikh , Katrin Kutepova , Yuri Kozlov ; GNU 3 , . . , , . Linux man-pages 6.06 31 2023 . uselib(2)