release/src/router/busybox/libbb/kernel_version.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Utility routines.
   4  *
   5  * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
   6  *
   7  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   8  */
   9
  10 #include "libbb.h"
  11 /* After libbb.h, since it needs sys/types.h on some systems */
  12 #include <sys/utsname.h>  /* for uname(2) */
  13
  14
  15 /* Returns current kernel version encoded as major*65536 + minor*256 + patch,
  16  * so, for example,  to check if the kernel is greater than 2.2.11:
  17  *
  18  *     if (get_linux_version_code() > KERNEL_VERSION(2,2,11)) { <stuff> }
  19  */
  20 int FAST_FUNC get_linux_version_code(void)
  21 {
  22         struct utsname name;
  23         char *s;
  24         int i, r;
  25
  26         if (uname(&name) == -1) {
  27                 bb_perror_msg("can't get system information");
  28                 return 0;
  29         }
  30
  31         s = name.release;
  32         r = 0;
  33         for (i = 0; i < 3; i++) {
  34                 r = r * 256 + atoi(strtok(s, "."));
  35                 s = NULL;
  36         }
  37         return r;
  38 }