source: npl/mediabox/lcdproc_edwin/src/clients/lcdproc/load.c

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>

#include "../../shared/sockets.h"

#include "main.h"
#include "mode.h"
#include "load.h"

int loadavg_fd = 0;

static double get_loadavg(void);

static double get_loadavg(void) 
{
  double load;

  reread(loadavg_fd, "get_load:");
  sscanf(buffer, "%lf", &load);
  return load; 
}


int load_init()
{
   if(!loadavg_fd)
      loadavg_fd = open("/proc/loadavg",O_RDONLY);
   
   return 0;
}

int load_close()
{
   if(loadavg_fd)
      close(loadavg_fd);

   loadavg_fd = 0;
   
   return 0;
}


///////////////////////////////////////////////////////////////////////////
// Shows a display very similar to "xload"'s histogram.
//

int xload_screen(int rep, int display)
{
   static int first = 1;
   static float loads[LCD_MAX_WIDTH];
   int n, i;
   float loadmax=0, factor, x;
   int status = 0;

  
   if(first)  // Only the first time this is ever called...
   {
      first = 0;
      memset(loads, 0, sizeof(float)*LCD_MAX_WIDTH);
      
      sock_send_string(sock, "screen_add X\n");
      sprintf(buffer, "screen_set X name {X-Load: %s}\n", host);
      sock_send_string(sock, buffer);
      // Add the vbars...
      for(i=1; i<lcd_wid; i++)
      {
         sprintf(tmp, "widget_add X %i vbar\n", i);
         sock_send_string(sock, tmp);
         sprintf(tmp, "widget_set X %i %i %i 0\n", i, i, lcd_hgt);
         sock_send_string(sock, tmp);
      }
      // And add a title...
      if(lcd_hgt >= 4)
      {
         sock_send_string(sock, "widget_add X title title\n");
         sock_send_string(sock, "widget_set X title {LOAD        }\n");
      }
      else
      {
         sock_send_string(sock, "widget_add X title string\n");
         sock_send_string(sock, "widget_set X title 1 1 {LOAD}\n");
         sock_send_string(sock, "widget_del X heartbeat\n");
      }
      sock_send_string(sock, "widget_add X zero string\n");
      sock_send_string(sock, "widget_add X top string\n");
      sprintf(tmp, "widget_set X zero %i %i 0\n", lcd_wid, lcd_hgt);
      sock_send_string(sock, tmp);
      sprintf(tmp, "widget_set X top %i %i 1\n",
              lcd_wid, (lcd_hgt==2)?1:2);
      sock_send_string(sock, tmp);
   }



   for(n=0; n<(lcd_wid-2); n++) loads[n] = loads[n+1];
   loads[lcd_wid-2] = get_loadavg();

   for(n=0; n<lcd_wid-1; n++)
      if(loads[n] > loadmax) loadmax = loads[n];

   n = (int)loadmax;
   if ((float)n < loadmax) { n++; } 
   sprintf(tmp, "widget_set X top %i %i %i\n",
           lcd_wid, (lcd_hgt==2)?1:2, n);
   //if(display) sock_send_string(sock, tmp);
   sock_send_string(sock, tmp);

   
   if (loadmax < 1.0) factor = (float)(lcd_cellhgt) * ((lcd_hgt==2)?2.0:3.0);
   else factor = (float)(lcd_cellhgt) * ((lcd_hgt==2)?2.0:3.0) / (float)n;

   for(n=0; n<lcd_wid-1; n++)
   {
      x = (loads[n] * factor);
      //###test!!!!!!
      //x=n;
      
      sprintf(tmp, "widget_set X %i %i %i %i\n", n+1, n+1, lcd_hgt, (int)x);
      //if(display) sock_send_string(sock, tmp);
      sock_send_string(sock, tmp);
   }
   
   if(loadmax < LOAD_MIN)
   {
      status = BACKLIGHT_OFF;
   }
   if(loadmax > LOAD_MIN)
   {
      status = BACKLIGHT_ON;
   }
   if(loads[lcd_wid-2] > LOAD_MAX)
   {
      status = BLINK_ON;
   }

   // And now the title...
   if(lcd_hgt >= 4)
      sprintf(tmp, "widget_set X title {LOAD %2.2f: %s}\n",
              loads[lcd_wid-2], host);
   else
      sprintf(tmp, "widget_set X title 1 1 {%s %2.2f}\n",
              host, loads[lcd_wid-2]);
   //if(display) sock_send_string(sock, tmp);
   sock_send_string(sock, tmp);


   return status;
} // End xload_screen()