title: dlopen failed: cannot open shared object file: No such file or directory
body: <p>The problem is I use <code>dlopen</code> to load a library (the .so is written by me, it's not a system library), but I got the error shown in the title.</p>
  
  <ol>
  <li>I have included <code>dlfcn.h</code> </li>
  <li>in compiler, I used the <code>-ldl</code> command</li>
  <li>What I want to load is just the source code folder, I tried to add <code>-L.</code>, but it did not work.</li>
  </ol>