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copied!<p>Since it looks like you're using something UNIX-y, just use <code>dlopen</code> instead of dynamically linking your driver app against the missing symbol.</p> <p>Full sequence is:</p> <ol> <li>iterate over all submitted .so library filenames somehow (maybe you have one directory with <em>studentname.so</em> or something)</li> <li>load each library</li> <li>get the entry point function</li> <li>call it</li> <li>unload library (optional, I guess)</li> </ol> <p>like so:</p> <pre><code>void *lib = dlopen(filename, RTLD_LOCAL); void *libfun = dlsym(lib, "doAction"); if (libfun == NULL) cout << "student failed by not providing doAction() in " << filename << endl; else { void (*doAction)(void) = (void (*)(void)) libfun; // no, I can't remember the correct syntax for casting to function pointer cout << "calling " << filename << ":doAction()" << endl; doAction(); // is there some way to tell if it succeeded? cout << "unloading " << filename << endl; dlclose(lib); } </code></pre> <p>Notes:</p> <ul> <li>if the interface is the same in each case (ie, <code>void (*)()</code>), you could make this configurable by directory name and symbol name, and it'd work for more than one test</li> <li>in fact, if the interface is NOT what you expect, the function pointer cast will do horrible things, so careful with this</li> <li>finally, if the student used C++, their function name symbol will be mangled. Tell them to declare the entry-point as <code>extern "C" void doAction()</code> to avoid that.</li> <li>the <code>RTLD_LOCAL</code> flag should stop anything in one student's library interfering with another (if you don't unload), but there are other flags it may be sensible to add <ul> <li>specifically, <code>RTLD_NOW</code> will cause <code>dlopen</code> to fail if the student lib has an unresolved external reference it can't figure out (so you can handle it gracefully, by failing them): otherwise your program may just crash when you call <code>doAction</code>.</li> </ul></li> </ul> <hr> <p>Although I think the above is <em>better</em> than the solution you're directly asking for help with, I did also find a reference to <code>dl_iterate_phdr</code> while double-checking the docs. If you're on Linux specifically, and if the <code>dl_phdr_info.dlpi_name</code> is actually the filename ... you might be able to get it that way.</p> <p>I still think it's much uglier, though.</p>

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