kernel_proc.c

通过对proc的文件进行操作来了解KERNEL的有关信息

#include <stdio.h>
#include <string.h>

float version_info()
{
  FILE* fp;
  char buffer[1024]; 
  size_t bytes_read;
  char* match; 
  char *version_info;//Read the entire contents of /proc/version the buffer.
  fp= fopen("/proc/version","r"); 
  bytes_read= fread(buffer, 1, sizeof(buffer), fp);
  fclose(fp);//Bail if read failed or if buffer isn’t big enough.
  if (bytes_read== 0 || bytes_read== sizeof(buffer))
    return 0;//NUL-terminate the text.
  buffer[bytes_read] = '\0';//Locate the line that starts with “cpuMHz”.
  match = buffer;//strstr(buffer, “cpuMHz”);
  //if (match == NULL)
  //  return 0;//Parse the line to extract the clock speed.
  sscanf(match,"Linux version %s",version_info);
  printf("The kernel version is %s\n",version_info);
    return 0;
}

float cpu_type()
{
  FILE* fp;
  char buffer[1024]; 
  size_t bytes_read;
  char* match; 
  char *cpu_type;
  //Read the entire contents of /proc/cpuinfointo the buffer.
  fp= fopen("/proc/cpuinfo","r"); 
  bytes_read= fread(buffer, 1, sizeof(buffer), fp);
  fclose(fp);//Bail if read failed or if buffer isn’t big enough.
  if (bytes_read== 0 || bytes_read== sizeof(buffer))
    return 0;//NUL-terminate the text.
  buffer[bytes_read] = '\0';//Locate the line that starts with “cpuMHz”.
  
  match =strstr(buffer,"vendor_id");
  if (match == NULL)
    return 0;//Parse the line to extract the clock speed.
  sscanf(match,"vendor_id	:%s",cpu_type);
  printf("The cpu type is %s\n",cpu_type);
    return 0;
}

float cpu_model()
{
  FILE* fp;
  char buffer[1024]; 
  size_t bytes_read;
  char* match; 
  char *cpu_model;
  //Read the entire contents of /proc/cpuinfointo the buffer.
  fp= fopen("/proc/cpuinfo","r"); 
  bytes_read= fread(buffer, 1, sizeof(buffer), fp);
  fclose(fp);//Bail if read failed or if buffer isn’t big enough.
  if (bytes_read== 0 || bytes_read== sizeof(buffer))
    return 0;//NUL-terminate the text.
  buffer[bytes_read] = '\0';//Locate the line that starts with “cpuMHz”.
  
  match =strstr(buffer,"model name");
  if (match == NULL)
    return 0;//Parse the line to extract the clock speed.
  sscanf(match,"model name	:%s",cpu_model);
  printf("The cpu model name is %s\n",cpu_model);
  //printf("%s",cpu_model+=(strlen(cpu_model)+1));

  printf("sizeof(cpu_model) is %d\n",strlen(cpu_model));
    return 0;
}

float time_since_boot()
{
  int  days,hours,minutes;
  float seconds;
  FILE* fp;
  char buffer[1024]; 
  size_t bytes_read;
  float time;
  //Read the entire contents of /proc/cpuinfointo the buffer.
  fp= fopen("/proc/uptime","r"); 
  bytes_read= fread(buffer, 1, sizeof(buffer), fp);
  fclose(fp);//Bail if read failed or if buffer isn’t big enough.
  if (bytes_read== 0 || bytes_read== sizeof(buffer))
    return 0;//NUL-terminate the text.
  buffer[bytes_read] = '\0';//Locate the line that starts with “cpuMHz”.
  sscanf(buffer,"%f",&time);
  days=time/(60*60*24);
  hours=(time-days*60*60*24)/(60*60);
  minutes=(time-days*60*60*24-hours*60*60)/60;
  seconds=(time-days*60*60*24-hours*60*60-minutes*60);
  printf("Time since booted is %d:%d:%d:%d\n",days,hours,minutes,(int)seconds);
    return 0;
}

main()
{
  version_info();
  cpu_type();
  cpu_model();
  time_since_boot();
}