/* downloadspeed.c   by Michael Thorpe   2003-09-19 */

/* This is because glibc is a festering boil on the face of computerdom... */
#define _FILE_OFFSET_BITS 64

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/stat.h>

/* WARNING!  Kludge alert! */
#ifndef sleep
/* This is because usleep is much more efficient than sleep on my machine: */
#define sleep(x) usleep((x)*1000000)
#endif

int main(int argc,char **argv) {
	struct stat ss;
	int histlen,histpos,i,j,histsize;
	off_t *hist;
	char *s;

	if(argc==3 && argv[1][0]=='-' && argv[1][1]=='c' && !argv[1][2]) {
		while(1) {
			if(stat(argv[2],&ss)) {
				perror("stat");
				return(1);
			}
			if(ss.st_mtime<=ss.st_atime)
				ss.st_mtime=ss.st_atime+1;
			printf("%lu\t%lu\r",(unsigned long)(ss.st_size/(ss.st_mtime-ss.st_atime)),(unsigned long)(ss.st_size));
			fflush(stdout);
			sleep(1);
		}
	} else if(argc==3 && argv[1][0]=='-' && argv[1][1]=='h' && !argv[1][2]) {
		i=8;
		if((s=getenv("COLUMNS"))) {
			i=atoi(s);
			i=(i-3-2)/8-2;
			if(i>17)
				i=17;
			if(i<1)
				i=1;
		}
		histsize=1<<(i-1);
		hist=(off_t *)malloc(histsize*sizeof(off_t));
		if(!hist) {
			perror("malloc");
			return(1);
		}
		if(stat(argv[2],&ss)) {
			perror("stat");
			return(1);
		}
		histlen=1;
		histpos=1;
		hist[0]=ss.st_size;
		printf("%10llu\r",ss.st_size);
		while(1) {
			fflush(stdout);
			sleep(1);
			if(stat(argv[2],&ss)) {
				perror("stat");
				return(1);
			}
			printf("%10llu",ss.st_size);
			for(i=1;i<=histlen;i<<=1) {
				if(histpos<i)
					j=histpos+histsize-i;
				else
					j=histpos-i;
				printf(" %7llu",(ss.st_size-hist[j])/i);
			}
			putchar('\r');
			hist[histpos++]=ss.st_size;
			if(histpos==histsize)
				histpos=0;
			if(histlen<histsize)
				histlen++;
		}
	} else if(argc>1 && (argv[1][0] != '-' || (argv[1][1]=='-' && !argv[1][2]))) {
		j=0;
		for(i=1;i<argc;i++) {
			if(stat(argv[i],&ss)) {
				fprintf(stderr,"stat(%s",argv[i]);
				perror(")");
				j=1;
				continue;
			}
			if(ss.st_mtime<=ss.st_atime)
				ss.st_mtime=ss.st_atime+1;
			printf("%lu\t%s\n",(unsigned long)(ss.st_size/(ss.st_mtime-ss.st_atime)),argv[i]);
		}
		return(j);
	} else {
		fputs("usage: downloadspeed {-[ch] <file> | <file1> [<file2> [..]]}\n",stderr);
		return(1);
	}
	return(0);
}