RTLDGLOBAL

RTLD_GLOBAL is a flag used with the dynamic linking loader function dlopen on POSIX-compliant systems. It instructs the dynamic linker to place the symbols defined by the loaded shared object into the global symbol namespace, making them available to resolve references in subsequently loaded shared libraries and in the main program.

RTLD_GLOBAL is defined in the header dlfcn.h and is used in conjunction with an access mode such as RTLD_LAZY or RTLD_NOW when calling dlopen. When this flag is set, the loaded object’s exports participate in symbol resolution for other modules; when it is not set (RTLD_LOCAL), the symbols remain private to the object and are not used for resolving references in other modules.

Practical considerations: using RTLD_GLOBAL can enable plugins or libraries that export symbols consumed by later modules, but it can also lead to symbol collisions or versioning issues if different libraries define the same symbol. Some environments impose restrictions on global symbols for security or stability reasons, and certain loader namespaces or sandboxing features may affect its behavior.

Example: dlopen("libplugin.so", RTLD_LAZY | RTLD_GLOBAL);

See also: RTLD_LAZY, RTLD_NOW, RTLD_LOCAL, and dlfcn.h.