/* splitfont: extract characters from font */

/* this is for iso fonts, no psf header, just 256 characters */

#include <stdio.h>

#include <fcntl.h>

#include <unistd.h>

#include <sys/stat.h>

void dosplit(int from, int to, char *fontbuf, int size, char *fontfile)

{

	int itemsize = size / 256;

	int i, fd;

	char *p, *q, s;

	char filename[4096];

	if (from < 0 || from > 255 || to < 0 || to > 255) {

		fprintf(stderr, "splitfont: bad argument %s,%s\n",

		        from, to);

		exit(1);

	}

	if (strlen(fontfile) >= sizeof(filename) - 4) {

		fprintf(stderr, "splitfont: ridiculously long name\n");

		exit(1);

	}

	while (from <= to) {

		sprintf(filename, "%s.%02x", fontfile, from);

		if ((fd = open(filename, O_WRONLY | O_CREAT, 0666)) < 0) {

			perror("splitfont");

			fprintf(stderr, "cannot open %s for writing\n", filename);

		}

		p = &fontbuf[from * itemsize];

		if (write(fd, p, itemsize) != itemsize) {

			perror("splitfont");

			fprintf(stderr, "error writing %s\n", filename);

		}

		close(fd);

		from++;

	}

}

int main(int argc, char **argv)

{

	struct stat statbuf;

	char fontbuf[4096];

	int fd;

	char *p, *q;

	int from, to;

	if (argc != 3) {

		fprintf(stderr, "call: splitfont fontfile 17,23-30,...\n");

		exit(1);

	}

	if (stat(argv[1], &statbuf)) {

		perror("splitfont");

		fprintf(stderr, "cannot stat fontfile %s", argv[1]);

		exit(1);

	}

	if (statbuf.st_size > 4096) {

		fprintf(stderr, "splitfont: file unexpectedly large\n");

		exit(1);

	}

	if (statbuf.st_size % 256) {

		fprintf(stderr, "splitfont: file size not a multiple of 256\n");

		exit(1);

	}

	if ((fd = open(argv[1], O_RDONLY)) < 0) {

		perror("splitfont");

		fprintf(stderr, "cannot open fontfile %s", argv[1]);

		exit(1);

	}

	if (read(fd, fontbuf, statbuf.st_size) != statbuf.st_size) {

		perror("splitfont");

		fprintf(stderr, "error reading fontfile %s", argv[1]);

		exit(1);

	}

	p = argv[2];

	while (1) {

		to = from = strtoul(p, &q, 0);

		if (*q == '-') {

			p  = q + 1;

			to = strtoul(p, &q, 0);

		}

		if (*q && *q != ',') {

			fprintf(stderr, "splitfont: garbage in %s\n", p);

			exit(1);

		}

		dosplit(from, to, fontbuf, statbuf.st_size, argv[1]);

		if (!*q)

			break;

		p = q + 1;

	}

	return 0;

}