/* Bandwidth monitor - Written by Michael Hayes. 
 *
 * Permission to use source is granted as long as it retains this tag.
 * 
 */

#include <stdio.h>
#include <time.h>
#include <string.h>
#include <stddef.h>
#include <stdlib.h>
//#define TRUE 1
//#define FALSE 0

static unsigned long int bosent;
static unsigned long int borec;
static unsigned long long int bsent;
static unsigned long long int brec;
static unsigned long int bsentrem;
static unsigned long int brecrem;

int main ()
{
	struct tm che;
	time_t thetime;
	long int old_time;
	FILE *fp;
	thetime = time(NULL);
	localtime_r(&thetime, &che);
	old_time = 100;
	printf("Beginning.\n\r\n\r");
	while (old_time> -10)
	{
		thetime = time(NULL);
		localtime_r(&thetime, &che);
		if (old_time == che.tm_sec)
			continue;
		old_time = che.tm_sec;
		//if (fp != NULL)
		//	parse_bytes(fp);
		if ((fp = fopen("/proc/net/dev","r")) == NULL)
		{
			printf("Unable to open proc file!\n\n");
			return 0;
		}
		
    					
		while (!feof(fp))
		{
			
			unsigned char  bline[500];
			unsigned long int _brec=0;
			unsigned long int _bsent=0;
			fetchline(bline, 1000, fp);
			if (strstr(bline, "eth0:"))
			{
				char deli[] = " ";
				char *token, *buf;

				buf = strdup(&bline[7]);
				
				token = strtok(buf, deli); // bytes (rec)
				brec = strtoll(token, NULL, 0);
				
			        token = strtok(NULL, deli); // packets
				token = strtok(NULL, deli); // errs
				token = strtok(NULL, deli); //  drop
				token = strtok(NULL, deli); // fifo
				token = strtok(NULL, deli); // frame
				token = strtok(NULL, deli); // compressed
				token = strtok(NULL, deli); // multicast
                                token = strtok(NULL, deli); // bytes (send)
				bsent = strtoll (token,NULL,0);
                                token = strtok(NULL, deli); // packets
                                token = strtok(NULL, deli); // errs
                                token = strtok(NULL, deli); //  drop
                                token = strtok(NULL, deli); // fifo
                                token = strtok(NULL, deli); // frame
                                token = strtok(NULL, deli); // compressed
                                token = strtok(NULL, deli); // multicast

				//int _brec,_bsent=0;
				if (bosent == 0 && borec == 0)
				{
					bosent = bsent;
					borec = brec;
					
				}

				_brec = brec - borec;
				_bsent = bsent - bosent;
				if (_bsent < 1024)
					bsentrem = _bsent;
				if (_brec < 1024)
					brecrem = _brec;
				_bsent = _bsent / 1024;
				_brec = _brec /1024;

							
				
				if (_brec % 1024 != 0)
					brecrem = _brec % 1024;
				
				if (_bsent % 1024 != 0)
					bsentrem = _bsent % 1024;
			

				printf("\e[1A\e[2K");
				printf("Send: %6u.%-4ukB/s - Rec: %6u.%-4ukB/s\n",_bsent, bsentrem, _brec, brecrem);
				
				
				bosent = bsent;
				borec = brec;
				bsentrem=0;
				brecrem=0;
		
				
					
			}
			
		}
		fclose(fp);
		
			
		
		
		
	}
	
	return 0;
}

int fetchline(char s[], int lim, FILE *fp)
{
	int c, i, j;
	for(i = 0, j = 0; (c = getc(fp))!=EOF && c != '\n'; ++i)
	{
		if(i < lim - 1)
		{
			s[j++] = c;
		}
	}
  	if(c == '\n')
	{
		if(i <= lim - 1)
		{
			s[j++] = c;
		}
		++i;
	}
	s[j] = '\0';
	return i;
}