Linux操作系统内核实习（一）

Exercise One

Part A

1. What is the cpu type and model?

/proc/cpuinfo

2. What version of the linux kernel is being used?

/proc/version

3. How long has it been since the system was last booted?

/proc/uptime

4. How much of the total cpu time has been spent executing in user model? System model? Idle?

/proc/stat

5. How much memory is configured into it?

/proc/meminfo

6. How many disk read/write requests have been made?
How many context switches has the kernel performed?
How many processes have been created since the system was booted?

/proc/stat

Part B: Programming

#include <stdio.h>
#define MAX_CHAR 80

int main(int argc, char* argc[])
{
FILE* filp;
char c[80];
char* ctemp;
int err;

filp = fopen("/proc/cpuinfo", "r");
if (filp < 0)
goto fail;
printf("The cpu type and model:/n");
while ((ctemp = fgets(c, MAX_CHAR, filp)) > 0)
{
if (strstr(c, "vendor_id") || (strstr(c, "model") && strstr(c, "name")) || (strstr(c, "cpu") && strstr(c, "MHz")))
printf(c);
}
if (ctemp < 0)
goto fail;

filp = fopen("/proc/uptime", "r");
if (filp < 0)
goto fail;
if ((ctemp = fgets(c, MAX_CHAR, filp)) >= 0)
{
if (sscanf(c, "%d", &err))
printf("seconds:%d/n", err);
printf("%d:%d:%d:%d/n", err/(24*3600), err/3600-err(24*3600)*24, err/60-err/3600*60, err%60);
}

return 0;
fail:
return -1;
}

The program above is tested in Redhat 9.0.

chen 2006-5-21