compile/cpu-screen.c

   1 /*
   2  * Filename:      cpu-screen.c
   3  * Purpose:       output current / available cpu frequence (useful for integration into GNU screen)
   4  * Authors:       grml-team (grml.org), (c) Michael Prokop <mika@grml.org>
   5  * Bug-Reports:   see http://grml.org/bugs/
   6  * License:       This file is licensed under the GPL v2.
   7  * Latest change: Tue Mar 28 11:01:43 CEST 2006 [mika]
   8  *******************************************************************************/
   9
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <string.h>
  13
  14 #define LINE_LEN 10
  15
  16 static int cpu_cur_frequency(void)
  17 {
  18         FILE *fp;
  19         char puffer[LINE_LEN];
  20         char *nl;
  21         fp = fopen("/sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq", "r");
  22         if(!fp) {
  23                 printf("[ cpufreq n/a ]\n");
  24                 return 1;
  25         }
  26         else {
  27                 while(fgets(puffer, LINE_LEN, fp)){
  28                         if ((nl = strchr(puffer,'\n')))
  29                             *nl = 0;
  30                         int value = atoi(puffer);
  31                         value /= 1000;
  32                         fprintf(stdout, "%u", value);
  33                 }
  34         }
  35         fclose(fp);
  36
  37         return 0;
  38 }
  39
  40 static int cpu_max_frequency(void)
  41 {
  42         FILE *fp;
  43         char puffer[LINE_LEN];
  44         fp = fopen("/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq", "r");
  45         if(!fp) {
  46                 return 2;
  47         }
  48         else {
  49                 while(fgets(puffer, LINE_LEN, fp)){
  50                         int value = atoi(puffer);
  51                         value /= 1000;
  52                         fprintf(stdout, "%u\n", value);
  53                 }
  54         }
  55         fclose(fp);
  56
  57         return 0;
  58 }
  59
  60 // function inspired by cpufreq-info.c of cpufrequtils-0.4 by Dominik Brodowski
  61 static int count_cpus(void)
  62 {
  63         FILE *fp;
  64         char value[LINE_LEN];
  65         unsigned int ret = 0;
  66         unsigned int cpunr = 0;
  67
  68         fp = fopen("/proc/stat", "r");
  69         // assume "1" cpu if we can't count it
  70         if(!fp) {
  71                 return 1;
  72         }
  73
  74         while (!feof(fp)) {
  75                 fgets(value, LINE_LEN, fp);
  76                 if (strlen(value) < (LINE_LEN - 2))
  77                         continue;
  78                 if (strstr(value, "cpu "))
  79                         continue;
  80                 if (sscanf(value, "cpu%d ", &cpunr) != 1)
  81                         continue;
  82                 if (cpunr > ret)
  83                         ret = cpunr;
  84         }
  85         fclose(fp);
  86
  87         return (ret+1);
  88 }
  89
  90 int main()
  91 {
  92         int cpus;
  93         int ret;
  94
  95         cpus = count_cpus();
  96         if (cpus != 1){
  97                 printf("%d * ", cpus);
  98         }
  99
 100         ret = cpu_cur_frequency();
 101         if (!ret) {
 102                 printf(" / ");
 103                 ret = cpu_max_frequency();
 104         }
 105         return (ret);
 106 }
 107
 108 /* EOF */