2019独角兽企业重金招聘Python工程师标准>>> 
Linux get hardware information over C
ioctl(input output controller)函数获取磁盘信息
- 出现同一份代码RedHat上可以拿到
/dev/sdaserial number, 在Ubuntu上出错
获取主板信息
出现有些主板找不到serial number，暂时有两种方法：
- dmidecode工具，github.com上有repo fork
- 从
/sys/class/dmi/id/中直接读取
get mac info
获得Unix/Linux系统中的IP、MAC地址等信息_
.. _获得Unix/Linux系统中的IP、MAC地址等信息: http://programmerdigest.cn/2010/07/1050.html
- ioctl函数没有纳入POXIS规范，各系统对ioctl的实现也不尽相同
- ioctl函数的参数只有3个，但却是Unix中少有的几个“家族类”复杂函数.在传统上ioctl函数是用于那些普遍使用、但不适合归入其他类别的任何特殊的系统接口……网络程序（一般是服务器程序）中ioctl常用于在程序启动时获得主机上所有接口的信息：接口的地址、接口是否支持广播、是否支持多播，等等。
get cpu info
- 方法一：C语言内部实现，使用
libcpuid库_
.. _libcpuid库: http://libcpuid.sourceforge.net/
.. code-block:: c
struct cpu_raw_data_t raw;
struct cpu_id_t data;
if (cpuid_get_raw_data(&raw) < 0) {
printf("Sorry, cannot get the CPUID raw data.\n");
printf("Error: %s\n", cpuid_error());
return -2;
}
if (cpu_identify(&raw, &data) < 0) {
printf("Sorrry, CPU identification failed.\n");
printf("Error: %s\n", cpuid_error());
return -3;
}
printf("Found: %s CPU\n", data.vendor_str);
printf("Processor model is `%s'\n", data.cpu_codename);
printf("The full brand string is `%s'\n", data.brand_str);
printf("The processor has %dK L1 cache and %dK L2 cache\n", data.l1_data_cache, data.l2_cache);
- 方法二：从
/proc/cpuinfo中直接读取，/proc/cpuinfo的信息的格式说明在kernel中的代码_
.. _信息的格式说明在kernel中的代码: http://lxr.free-electrons.com/source/arch/x86/kernel/cpu/proc.c#L57
.. code-block:: c
#define _GNU_SOURCE
#include
#include
int main(int argc, char **argv)
{
FILE *cmdline = fopen("/proc/cpuinfo", "rb");
char *arg = 0;
size_t size = 0;
while(getdelim(&arg, &size, 0, cmdline) != -1)
{
puts(arg);
}
free(arg);
fclose(cmdline);
return 0;
}
判断是否虚拟机
使用RedHat virt-what工具/库，此工具可以判断很多VM
.. code-block:: c
#if defined(__i386__) || defined(__x86_64__)
static unsigned int
cpuid (unsigned int eax, char *sig)
{
unsigned int *sig32 = (unsigned int *) sig;
asm volatile (
"xchgl %%ebx,%1; xor %%ebx,%%ebx; cpuid; xchgl %%ebx,%1"
: "=a" (eax), "+r" (sig32[0]), "=c" (sig32[1]), "=d" (sig32[2])
: "0" (eax));
sig[12] = 0;
return eax;
}
static void
cpu_sig (char* sig)
{
unsigned int base = 0x40000000, leaf = base;
unsigned int max_entries;
memset (sig, 0, sizeof sig);
max_entries = cpuid (leaf, sig);
puts (sig);
// return for determine
if(strlen(siq) > 0){
return;
}
/* Most hypervisors only have information in leaf 0x40000000, but
* upstream Xen contains further leaf entries (in particular when
* used with Viridian [HyperV] extensions). CPUID is supposed to
* return the maximum leaf offset in %eax, so that's what we use,
* but only if it looks sensible.
*/
if (max_entries > 3 && max_entries < 0x10000) {
for (leaf = base + 0x100; leaf <= base + max_entries; leaf += 0x100) {
memset (sig, 0, sizeof sig);
cpuid (leaf, sig);
puts (sig);
// if not empty, is ok
if(strlen(sig) > 0){
return;
}
}
}
}
#else /* !i386, !x86_64 */
static void
cpu_sig (void)
{
/* nothing for other architectures */
}
#endif
系统所在磁盘信息
先从 /etc/mtab 获取 /boot 所在硬盘，然后用 ioctl 获取，未确定此方式的稳定性
.. code-block:: c
FILE *fp;
char disk_name[10];
char str_find[] = "/boot";
char buf_line[128];
static struct hd_driveid hd;
int fd;
int tmp_len = 0;
fp = fopen ("/etc/mtab", "rb");
if (fp == NULL)
{
fprintf(stderr, "No /etc/mtab file.\n");
return 0;
}
while(fgets(buf_line, sizeof(buf_line), fp)) {
if(strstr(buf_line, str_find) != NULL){
printf("debug: %s\n", buf_line);
break;
}
}
// TODO "/boot" extract
if(sscanf(buf_line, "%s /boot", disk_name) == -1)
{
printf("Error: can not get disk name\n");
}
// delete number, e.g. /dev/sda1
tmp_len = strlen(disk_name);
disk_name[tmp_len -1 ] = '\0';
if (geteuid() > 0) {
printf("ERROR: Must be root to use\n");
exit(1);
}
// TODO
if ((fd = open(disk_name, O_RDONLY|O_NONBLOCK)) < 0) {
printf("ERROR: Cannot open device %s\n", disk_name);
exit(1);
}
if (!ioctl(fd, HDIO_GET_IDENTITY, &hd)) {
const int nSNLength = 20;
strSN = "";
for(int i=0; i < nSNLength; i++){
if(hd.serial_no[i] < 32 || hd.serial_no[i] == 127)
{
strSN += '.';
}
else{
strSN += (char)hd.serial_no[i];
}
}
printf("debug: Disk Serial Number: %.20s\n", strSN.GetData());
return 1;
} else if (errno == -ENOMSG) {
printf("No hard disk identification information available\n");
return 0;
} else {
perror("ERROR: HDIO_GET_IDENTITY");
exit(1);
}
PS: 虽rst与markdown格式相近，但OSC对rst不支持，很多地方没渲染啊。