/*%cc -n -O % -o comhex
 * comhex - convert .com files to (intel) .hex format
 *
 * operates just like 'cat'
 *
 */

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>

char	stdbuf[BUFSIZ];

main(argc, argv)
char **argv;
{
	int fflg = 0;
	register FILE *fi;
	register c;
	register cx;
	int ccount;
	int address;
	int checksum;
	int dev, ino = -1;
	struct stat statb;

	setbuf(stdout, stdbuf);
	for( ; argc>1 && argv[1][0]=='-'; argc--,argv++) {
		switch(argv[1][1]) {
		case 0:
			break;
		case 'u':
			setbuf(stdout, (char *)NULL);
			continue;
		}
		break;
	}
	fstat(fileno(stdout), &statb);
	statb.st_mode &= S_IFMT;
	if (statb.st_mode!=S_IFCHR && statb.st_mode!=S_IFBLK) {
		dev = statb.st_dev;
		ino = statb.st_ino;
	}
	if (argc < 2) {
		argc = 2;
		fflg++;
	}
	while (--argc > 0) {
		if (fflg || (*++argv)[0]=='-' && (*argv)[1]=='\0')
			fi = stdin;
		else {
			if ((fi = fopen(*argv, "r")) == NULL) {
				fprintf(stderr, "comhex: can't open %s\n", *argv);
				continue;
			}
		}
		fstat(fileno(fi), &statb);
		if (statb.st_dev==dev && statb.st_ino==ino) {
			fprintf(stderr, "comhex: input %s is output\n",
			fflg?"-": *argv);
			fclose(fi);
			continue;
		}
		ccount = 0;
		address = 0x0100;	/* cpm load offset */

		while ((c = getc(fi)) != EOF){
			if (ccount < 1){
				printf(":10");	/* lead-in, 16 bytes follow */
				puthex(address,4);	/* first address */
				printf("00");		/* record type */
				checksum = (address/256) + (address%256) + 16;
			}
			cx = (c & 0x00ff);
			puthex(cx,2);		/* the byte in two nibbles */

			checksum += cx;
			ccount++;
			address++;

			if (ccount > 15){ 
				checksum = -checksum;
				puthex( checksum, 2);	/* the checksum */
				printf("\n");
				checksum = 0;
				ccount = 0;
			}
		}
		printf(":0000000000\n");	/* this is the end record */

		if (fi!=stdin)
			fclose(fi);
	}
	return(0);
}

puthex(cx,cols)

int cx;
int cols;

{
	char h;
	int i;
	int pos;

	for (i = 0; i < cols; i++){
		pos = cols - i - 1;
		h = ((cx >> (pos * 4)) & 0x000f);
		h = h + (h < 10 ? '0' : '7');
		putchar( h & 0x7f);
	}
}