none/tests/fdleak.h

   1 #ifndef _FDLEAK_H_
   2 #define _FDLEAK_H_
   3
   4 #define _GNU_SOURCE
   5 #include <stdlib.h>
   6 #include <unistd.h>
   7 #include <stdio.h>
   8 #include <sys/stat.h>
   9
  10 #define DO(op) \
  11    ({ \
  12       long res = op; \
  13       if (res < 0) { \
  14          perror(#op); \
  15          exit(1); \
  16       }; \
  17       res; \
  18    })
  19
  20 /*
  21  * The macro below closes file descriptors inherited from the process
  22  * that forked the current process. Close these file descriptors right
  23  * after the start of main() in order to get consistent results across
  24  * different releases. Known behavior:
  25  * - Fedora Core 1's Perl opens /dev/pts/2 as fd 10.
  26  * - For Ubuntu 8.04, see also
  27  *   https://bugs.launchpad.net/ubuntu/+source/seahorse/+bug/235184
  28  */
  29 static void close_inherited (void) {
  30    struct stat sb;
  31    int i; int max_fds = sysconf (_SC_OPEN_MAX);
  32    if (max_fds < 0)
  33       max_fds = 1024; /* Fallback if sysconf fails, returns -1.  */
  34
  35    /* Only leave 0 (stdin), 1 (stdout) and 2 (stderr) open.  */
  36    for (i = 3; i < max_fds; i++)
  37       if (fstat (i, &sb) != -1) /* Test if the file descriptor exists first. */
  38          close(i);
  39 }
  40 #define CLOSE_INHERITED_FDS close_inherited ()
  41 /* Note that the following would be nicer, but close_range is fairly new.  */
  42 // #define CLOSE_INHERITED_FDS close_range (3, ~0U, 0)
  43
  44 #endif /* _FDLEAK_H_ */