I work on Linux. When my application links to the shared library (which doesn't hide symbols) all symbols from that library are visible. A shared library can also be loaded at runtime using dlopen. Is it possible to control symbols visiblity using dlopen mode parameter or I always have to get desire symbol using dlsym ?

CodePudding user response：

Your question is exceedingly unclear.

If you dlopen the library, then about the only way to get to any of its symbols is via dlsym.

However, if you dlopen a library with RTLD_GLOBAL, then its symbols become available for subsequently loaded libraries without using dlsym.

For example, if libfoo.so defines symbol foo, and if you dlopen("libfoo.so", RTLD_GLOBAL|...); and later dlopen("libbar.so", ...) which uses foo, that would work -- libbar.so will be able to use foo from libfoo.so without doing any dlsym calls.