title: strtok function and multithreading
body: <p>I read a lot of stuff about strtok(char* s1, char* s2) and its implementation. However, I still can not understand what makes it a dangerous function to use in multi-threaded program. Can somebody please give me an example of a multi-threaded program and explain the issue there? Please not that I am looking for an example that shows me where the problem arises.</p>
  
  <p>ps: strtok(char* s1, char* s2) is part of the C standard library.</p>