/*
 * hex2bin -- convert all hex strings in the form 0x12 into binary
 * hex2bin infile outfile
 * (c) 2005 Bernd 'Aard' Wachter, <bwachter@lart.info>
 *          http://bwachter.lart.info
 * You may use and redistribute this progrem under the terms and 
 * conditions of the GNU GPL V2
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>

#ifdef __WIN32__
#include <io.h>
#else
#include <unistd.h>
#endif

#ifdef __dietlibc__
#include <write12.h>
#else
static int __write1(const char *s){ write(1, s, strlen(s)); return 0; }
static int __write2(const char *s){ write(2, s, strlen(s)); return 0; }
#endif



int main(int argc, char **argv){
	int fd_in, fd_out, i=1;
	char buf[5];
	char bytebuf[2];
	long byte;

	if (argc!=3){
		__write2("Usage: hex2bin infile outfile\n");
		exit(-1);
	}

	if ((fd_in=open(argv[1], O_RDONLY))==-1){
		__write2("Unable to open in-file\n");
		exit(-1);
	}
	if ((fd_out=open(argv[2], O_RDWR | O_CREAT | O_TRUNC, S_IWRITE | S_IREAD))==-1){
		__write2("Unable to open out-file\n");
		exit(-1);
	}
	while (i>0){
		if ((i=read(fd_in, buf, 1))==-1) goto bye;
		if (buf[0]!='0') continue;
		if ((i=read(fd_in, buf+1, 1))==-1) goto bye;
		if (buf[1]!='x') continue;
		if ((i=read(fd_in, buf+2, 2))!=2) goto bye;
		else {
			byte=strtol(buf, NULL, 16);
			sprintf(bytebuf, "%c", byte);
			write(fd_out, bytebuf, 1);
		}
	}
 bye:
	close(fd_in);
	close(fd_out);
	return 0;
}