#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <unistd.h>
#include <fcntl.h>

int main(int argc, char **argv)
{
	int fd, i, pos;
	struct stat st;
	char *map;
	unsigned char *buf;
	size_t ps;
	unsigned int incore=0;
	unsigned int notincore=0;
	unsigned int percent=0;
	char obuf[64+2+1];
	
	if ( argc != 2 ) {
		printf("Usage: \n");
		printf("  %s filename\n", argv[0]);
		return 1;
	}
	
	if ( (fd=open(argv[1], O_RDONLY))<0 ) {
		perror("open()");
		return 1;
	}

	if ( fstat(fd, &st) ) {
		perror("open()");
		return 1;
	}

	if ( (map=mmap(NULL, st.st_size, PROT_READ, MAP_SHARED, fd, 0))
		== MAP_FAILED ) {
		perror("mmap()");
		return 1;
	}
	
	/* Don't bother if its empty */
	if ( !st.st_size ) {
		printf("[]\n");
		goto summary;
	}
	
	ps=getpagesize();

	if ( !(buf=(unsigned char *)calloc(1, st.st_size/ps)) ) {
		perror("calloc()");
		return 1;
	}

	if ( mincore(map, st.st_size, buf) ) {
		perror("mincore()");
		return 1;
	}


#if 0
	printf("%s: [", argv[1]);
	for(i=0; i<=st.st_size/ps; i++) {
		if ( buf[i] & 1 ) {
			incore++;
			printf("#");
		}else{
			notincore++;
			printf("_");
		}
	}
	printf("]\n");
#endif
	pos=0;
	for(;;) {
		int cont=1;

		obuf[0]='[';
		for(i=0; i<64; i++) {
			if ( pos<=st.st_size/ps ) {
				if ( buf[pos]&1 ) {
					obuf[i+1]='#';
					incore++;
				}else {
					obuf[i+1]='.';
					notincore++;
				}
			}else{
				cont=0;
				break;
			}
			pos++;
		}

		/* Print out this line */
		obuf[i+1]=']';
		obuf[i+2]='\0';
		printf("%s: %s\n", argv[1], obuf);

		if ( !cont ) break;
	}

summary:
	if ( incore+notincore )
		/* Fear my floating point skillz! */
		percent=(incore*10000)/(incore+notincore);
	else
		percent=100000;
	
	printf("%s: %u bytes, %u pages, %u cached (%u.%.2u%%), %u not cached\n",
		argv[1], st.st_size, incore+notincore,
		incore, percent/100, percent%100, notincore);

	return 0;
}