1  #include <dlfcn.h>
       2  #include <mcheck.h>
       3  #include <stdio.h>
       4  #include <stdlib.h>
       5  
       6  int
       7  main (void)
       8  {
       9    void *h1;
      10    void *h2;
      11    int (*fp) (void);
      12  
      13    mtrace ();
      14  
      15    /* Open the two objects.  */
      16    h1 = dlopen ("reldepmod5.so", RTLD_LAZY);
      17    if (h1 == NULL)
      18      {
      19        printf ("cannot open reldepmod5.so: %s\n", dlerror ());
      20        exit (1);
      21      }
      22    h2 = dlopen ("reldepmod6.so", RTLD_LAZY);
      23    if (h2 == NULL)
      24      {
      25        printf ("cannot open reldepmod6.so: %s\n", dlerror ());
      26        exit (1);
      27      }
      28  
      29    /* Get the address of the variable in reldepmod1.so.  */
      30    fp = dlsym (h2, "bar");
      31    if (fp == NULL)
      32      {
      33        printf ("cannot get address of \"bar\": %s\n", dlerror ());
      34        exit (1);
      35      }
      36  
      37    /* Call the function.  */
      38    puts ("calling fp for the first time");
      39    if (fp () != 0)
      40      {
      41        puts ("function \"call_me\" returned wrong result");
      42        exit (1);
      43      }
      44  
      45    /* Now close the first object.  It must still be around since we have
      46       an implicit dependency.  */
      47    if (dlclose (h1) != 0)
      48      {
      49        printf ("closing h1 failed: %s\n", dlerror ());
      50        exit (1);
      51      }
      52  
      53    /* Calling the function must still work.  */
      54    puts ("calling fp for the second time");
      55    if (fp () != 0)
      56      {
      57        puts ("function \"call_me\" the second time returned wrong result");
      58        exit (1);
      59      }
      60    puts ("second call succeeded as well");
      61  
      62    /* Close the second object, we are done.  */
      63    if (dlclose (h2) != 0)
      64      {
      65        printf ("closing h2 failed: %s\n", dlerror ());
      66        exit (1);
      67      }
      68  
      69    return 0;
      70  }