/*
 *  V2STRIP v0.2.7  Removes ID3v2 tags from MP3 files
 *
 *  Copyright (C) 2000 Mats Peterson
 *
 *  Please send any comments/bug reports to
 *  mats_peterson@swipnet.se  (Mats Peterson)
 */


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

#include "v2hdr.h"

#define PACKAGE "v2strip"
#define VERSION "0.2.7"

#define BLKSIZE 4096



static void strip(char *fname)
{
    FILE *in_f, *tmp_f;
    static char buf[BLKSIZE];
    char *tmpname, *s;
    int n;
    long hdrsize;
    ID3V2HDR hdr;
	
    if (! (in_f = fopen(fname, "rb"))) {
		perror("fopen");
		return;
    }
	
    fread(&hdr, sizeof(ID3V2HDR), 1, in_f);
    if (strncmp(hdr.id_str, "ID3", 3) ||
	    (hdr.version[0] == 0xff) || (hdr.version[1] == 0xff) ||
	    (hdr.size[0] >= 0x80) || (hdr.size[1] >= 0x80) ||
	    (hdr.size[2] >= 0x80) || (hdr.size[3] >= 0x80)) {
		fprintf(stderr, "Error: file '%s' does not have any valid ID3v2 tag\n",
			fname);
		fclose(in_f);
		return;
    }

    for (s = fname + strlen(fname) - 1; (s >= fname) && (*s != '\\'); s--);
    if (s < fname)
		tmpname = tempnam(".", "v2str");
    else {  /* *s == '\\' */
		if (s == fname) {
	    	tmpname = tempnam("\\", "v2str");
		} else {
	    	*s = '\0';
	    	tmpname = tempnam(fname, "v2str");
	    	*s = '\\';
		}
    }

    if (! tmpname) {
		fprintf(stderr, "Error: unable to generate temporary file name\n");
		fclose(in_f);
		return;
    }

    if (! (tmp_f = fopen(tmpname, "wb"))) {
		perror("fopen");
		free(tmpname);
		fclose(in_f);
		return;
    }

    printf("Stripping %s... ", fname);
    fflush(stdout);
    
    hdrsize = ((long)hdr.size[3] |
	    ((long)hdr.size[2] << (8 - 1)) |
	    ((long)hdr.size[1] << (16 - 2)) |
	    ((long)hdr.size[0] << (24 - 3))) + sizeof(ID3V2HDR);

#ifdef DEBUG
    printf("header size: %lX\n", hdrsize);
#endif

    fseek(in_f, hdrsize, SEEK_SET);

    while (1) {
		n = fread(buf, 1, BLKSIZE, in_f);
		if (ferror(in_f)) {
	    	fprintf(stderr, "Read error\n");
	    	goto error;
		}
		fwrite(buf, 1, n, tmp_f);
		if (ferror(tmp_f)) {
	    	fprintf(stderr, "Write error\n");
	    	goto error;
		}
		if (n < BLKSIZE)
	    	break;
    }

    fclose(in_f);
    fclose(tmp_f);

    if (remove(fname) == -1) {
		perror("remove");
		goto error2;
    }

    if (rename(tmpname, fname) == -1) {
		perror("rename");
		goto error2;
    }

    free(tmpname);
    printf("Done\n");
    return;
    
error:
    fclose(in_f);
    fclose(tmp_f);
error2:
    remove(tmpname);
    free(tmpname);
}


static void usage(void)
{
    fprintf(stderr, "%s v%s\n", PACKAGE, VERSION);
    fprintf(stderr, "usage: %s <file ...>\n", PACKAGE);
    exit(0);
}


int main(int argc, char **argv)
{
	struct ffblk ffblk;
    int i, done;

    if (argc == 1)
	usage();

    for (i = 1; i < argc; i++) {
		if (strpbrk(argv[i], "?*")) {
			done = findfirst(argv[i], &ffblk, 0);
			if (done) {
				fprintf(stderr, "Can't find any file matching '%s'\n",
						argv[i]);
				continue;
			}
			while (! done) {
				strip(ffblk.ff_name);
				done = findnext(&ffblk);
			}
		} else
			strip(argv[i]);
	}

    return 0;
}
.