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