title: cpp: usr/bin/ld: cannot find -l<nameOfTheLibrary>
body: <p>I created a cpp project, which used a lib file named: <code>libblpapi3_64.so</code>
  This file comes from a library which I download it from Internet.</p>
  
  <p>My project runs without any error. So I update it to bitbucket.
  Then my colleague downloads it and runs it at his own computer. But he gets an error: </p>
  
  <p><code>usr/bin/ld: cannot find -lblpapi3_64</code>.</p>
  
  <p>In fact, I have copied it into my project repository. I mean I created a file named lib under my project and all lib files that I used are in it.<br></p>
  
  <p>There are also other lib files such as <code>liblog4cpp.a</code>, but they are all good. Only the <code>libblpapi3_64.so</code> gets the error.<br></p>
  
  <p>Is it because it's a .so file not <code>.a</code> file? Or there is other reason?<br>
  Btw, the file name of <code>libblpapi3_64.so</code> is <code>green</code> and others files(.a) is <code>white</code>. I think it's not a link file, it's the original file.</p>