/*
 *  V2STRIP v0.2.10  Removes ID3v2 tags from MP3 files
 *
 *  Copyright (C) 2000 Mats Peterson
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 *
 *  Please send any comments/bug reports to
 *  matsp888@yahoo.com  (Mats Peterson)
 */


#include <config.h>
#include <stdio.h>
#ifdef STDC_HEADERS
# include <stdlib.h>
# include <string.h>
#else
void free(void *ptr);
int strncmp(const char *s1, const char *s2, size_t n);
#endif
#include <sys/stat.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#include <sys/types.h>
#else
int chown(const char *path, uid_t owner, gid_t group);
int chmod(const char *path, mode_t mode);
int mkstemp(char *template);
#endif
#include "v2hdr.h"


static void strip(char *fname)
{
    struct stat statbuf;
    FILE *in_f, *tmp_f;
    static char buf[BLKSIZE];
    char *tmpname;
    int n;
    long hdrsize;
    ID3V2HDR hdr;

    if (stat(fname, &statbuf) < 0) {
	perror("stat");
	fprintf(stderr, "problem with file '%s'\n", fname);
	return;
    }

    if (! (in_f = fopen(fname, "rb"))) {
	perror("fopen");
	fprintf(stderr, "problem with file '%s'\n", fname);
	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, "File '%s' does not have any valid ID3v2 tag\n",
		fname);
	fclose(in_f);
	return;
    }

    tmpname = malloc(strlen(fname) + 30);

    if (tmpname) {
	int fd;
	strcpy(tmpname, fname);
	strcat(tmpname, "v2stripXXXXXX");
	fd = mkstemp(tmpname);
	if (fd < 0) {
	    free(tmpname);
	    tmpname = NULL;
	} else {
	    if (! (tmp_f = fdopen(fd, "wb"))) {
		perror("fdopen");
		free(tmpname);
		fclose(in_f);
		return;
	    }
	}
    }
      
    if (! tmpname) {
	fprintf(stderr, "Error: unable to generate temporary file name\n");
	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 (rename(tmpname, fname) < 0) {
	perror("rename");
	fprintf(stderr, "%s -> %s\n", tmpname, fname);
	goto error2;
    }

    free(tmpname);

    if (chown(fname, statbuf.st_uid, statbuf.st_gid) < 0) {
	perror("chown");
	fprintf(stderr, "problem with file '%s'\n", fname);
    }

    if (chmod(fname, statbuf.st_mode) < 0) {
	perror("chmod");
	fprintf(stderr, "problem with file '%s'\n", fname);
    }

    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(1);
}


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

    if (argc == 1)
	usage();

    for (i = 1; i < argc; i++)
	strip(argv[i]);

    exit(0);
}
.