/*
 * extract file from trx file
 *
 * (c) 01/2005 Olaf Rempel <razzor at kopf minus tisch dot de>
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>

#include <sys/types.h>
#include "trxhdr.h"

#define BUFSIZE 32768

int main(int argc, char *argv[]) {
	struct trx_header trx;
	int cnt;
	FILE *fp;
	char *buf;

	if (argc <= 1) {
		printf("USAGE: untrx file.trx > file\n");
		exit(-1);
	}

	// open file
	if ((fp = fopen(argv[1], "r")) < 0) {
		perror(argv[1]);
		exit(-1);
	}

	// read header
	if ((cnt = fread(&trx, 1, sizeof(struct trx_header), fp)) < 0) {
		perror(argv[1]);
		fclose(fp);
		exit(-1);

	} else if (cnt < sizeof(struct trx_header)) {
		fprintf(stderr, "Truncated file: %s\n", argv[1]);
		fclose(fp);
		exit(-1);

	} else if (trx.magic == TRX_MAGIC) {
		if (trx.len > TRX_MAX_LEN || trx.len < sizeof(struct trx_header)) {
			fprintf(stderr, "Bad TRX Header: %s\n", argv[1]);
			fclose(fp);
			exit(-1);
		}

	} else if (trx.magic == PMON_MAGIC) {
		if (trx.len > PMON_MAX_LEN || trx.len < sizeof(struct trx_header)) {
			fprintf(stderr, "Bad PMON Header: %s\n", argv[1]);
			fclose(fp);
			exit(-1);
		}

	} else if (trx.magic == NVAR_MAGIC) {
		if (trx.len > NVRAM_MAX_LEN || trx.len < sizeof(struct trx_header)) {
			fprintf(stderr, "Bad NVRAM Header: %s\n", argv[1]);
			fclose(fp);
			exit(-1);
		}

	} else {
		fprintf(stderr, "Unknown Header Type: %s\n", argv[1]);
		fclose(fp);
		exit(-1);
	}

	trx.len -= sizeof(struct trx_header);

	if ((buf = malloc(BUFSIZE)) == NULL) {
		perror("malloc");
		exit(-1);
	}

	while (trx.len > 0 && !feof(fp)) {
		cnt = fread(buf, 1, BUFSIZE, fp);
		write(1, buf, cnt);
		trx.len -= cnt;
	}

	free(buf);
	fclose(fp);

	return 0;
}