git.sur5r.net Git - i3/i3status/blob - src/print_cpu_usage.c

   1 // vim:sw=8:sts=8:ts=8:expandtab
   2 #include <stdlib.h>
   3 #include <limits.h>
   4 #include <stdio.h>
   5 #include <string.h>
   6
   7 #ifdef __FreeBSD__
   8 #include <sys/types.h>
   9 #include <sys/sysctl.h>
  10 #include <sys/dkstat.h>
  11 #endif
  12
  13 #include "i3status.h"
  14
  15 static int prev_total = 0;
  16 static int prev_idle  = 0;
  17
  18 /*
  19  * Reads the CPU utilization from /proc/stat and returns the usage as a
  20  * percentage.
  21  *
  22  */
  23 void print_cpu_usage(const char *format) {
  24         const char *walk;
  25         char buf[1024];
  26         int curr_user = 0, curr_nice = 0, curr_system = 0, curr_idle = 0, curr_total;
  27         int diff_idle, diff_total, diff_usage;
  28
  29 #if defined(LINUX)
  30         static char statpath[512];
  31         strcpy(statpath, "/proc/stat");
  32         if (!slurp(statpath, buf, sizeof(buf)) ||
  33             sscanf(buf, "cpu %d %d %d %d", &curr_user, &curr_nice, &curr_system, &curr_idle) != 4)
  34                 goto error;
  35
  36         curr_total = curr_user + curr_nice + curr_system + curr_idle;
  37         diff_idle  = curr_idle - prev_idle;
  38         diff_total = curr_total - prev_total;
  39         diff_usage = (1000 * (diff_total - diff_idle)/diff_total + 5)/10;
  40         prev_total = curr_total;
  41         prev_idle  = curr_idle;
  42 #elif defined(__FreeBSD__)
  43         size_t size;
  44         long cp_time[CPUSTATES];
  45         size = sizeof cp_time;
  46         if (sysctlbyname("kern.cp_time", &cp_time, &size, NULL, 0) < 0)
  47                 goto error;
  48
  49         curr_user = cp_time[CP_USER];
  50         curr_nice = cp_time[CP_NICE];
  51         curr_system = cp_time[CP_SYS];
  52         curr_idle = cp_time[CP_IDLE];
  53         curr_total = curr_user + curr_nice + curr_system + curr_idle;
  54         diff_idle  = curr_idle - prev_idle;
  55         diff_total = curr_total - prev_total;
  56         diff_usage = (1000 * (diff_total - diff_idle)/diff_total + 5)/10;
  57         prev_total = curr_total;
  58         prev_idle  = curr_idle;
  59 #else
  60         goto error;
  61 #endif
  62         for (walk = format; *walk != '\0'; walk++) {
  63                 if (*walk != '%') {
  64                         putchar(*walk);
  65                         continue;
  66                 }
  67
  68                 if (strncmp(walk+1, "usage", strlen("usage")) == 0) {
  69                         printf("%02d%%", diff_usage);
  70                         walk += strlen("usage");
  71                 }
  72         }
  73         return;
  74 error:
  75         (void)fputs("Cannot read usage\n", stderr);
  76 }