unzip.c

quakeIII源码这个不用我多说吧

                                                  *pfile_info_internal,
                                                  char *szFileName,
												  uLong fileNameBufferSize,
                                                  void *extraField,
												  uLong extraFieldBufferSize,
                                                  char *szComment,
												  uLong commentBufferSize)
{
	unz_s* s;
	unz_file_info file_info;
	unz_file_info_internal file_info_internal;
	int err=UNZ_OK;
	uLong uMagic;
	long lSeek=0;

	if (file==NULL)
		return UNZ_PARAMERROR;
	s=(unz_s*)file;
	if (fseek(s->file,s->pos_in_central_dir+s->byte_before_the_zipfile,SEEK_SET)!=0)
		err=UNZ_ERRNO;


	/* we check the magic */
	if (err==UNZ_OK) {
		if (unzlocal_getLong(s->file,&uMagic) != UNZ_OK)
			err=UNZ_ERRNO;
		else if (uMagic!=0x02014b50)
			err=UNZ_BADZIPFILE;
	}
	if (unzlocal_getShort(s->file,&file_info.version) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getShort(s->file,&file_info.version_needed) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getShort(s->file,&file_info.flag) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getShort(s->file,&file_info.compression_method) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getLong(s->file,&file_info.dosDate) != UNZ_OK)
		err=UNZ_ERRNO;

    unzlocal_DosDateToTmuDate(file_info.dosDate,&file_info.tmu_date);

	if (unzlocal_getLong(s->file,&file_info.crc) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getLong(s->file,&file_info.compressed_size) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getLong(s->file,&file_info.uncompressed_size) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getShort(s->file,&file_info.size_filename) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getShort(s->file,&file_info.size_file_extra) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getShort(s->file,&file_info.size_file_comment) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getShort(s->file,&file_info.disk_num_start) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getShort(s->file,&file_info.internal_fa) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getLong(s->file,&file_info.external_fa) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getLong(s->file,&file_info_internal.offset_curfile) != UNZ_OK)
		err=UNZ_ERRNO;

	lSeek+=file_info.size_filename;
	if ((err==UNZ_OK) && (szFileName!=NULL))
	{
		uLong uSizeRead ;
		if (file_info.size_filename<fileNameBufferSize)
		{
			*(szFileName+file_info.size_filename)='\0';
			uSizeRead = file_info.size_filename;
		}
		else
			uSizeRead = fileNameBufferSize;

		if ((file_info.size_filename>0) && (fileNameBufferSize>0))
			if (fread(szFileName,(uInt)uSizeRead,1,s->file)!=1)
				err=UNZ_ERRNO;
		lSeek -= uSizeRead;
	}

	
	if ((err==UNZ_OK) && (extraField!=NULL))
	{
		uLong uSizeRead ;
		if (file_info.size_file_extra<extraFieldBufferSize)
			uSizeRead = file_info.size_file_extra;
		else
			uSizeRead = extraFieldBufferSize;

		if (lSeek!=0) {
			if (fseek(s->file,lSeek,SEEK_CUR)==0)
				lSeek=0;
			else
				err=UNZ_ERRNO;
		}
		if ((file_info.size_file_extra>0) && (extraFieldBufferSize>0)) {
			if (fread(extraField,(uInt)uSizeRead,1,s->file)!=1)
				err=UNZ_ERRNO;
		}
		lSeek += file_info.size_file_extra - uSizeRead;
	}
	else
		lSeek+=file_info.size_file_extra; 

	
	if ((err==UNZ_OK) && (szComment!=NULL))
	{
		uLong uSizeRead ;
		if (file_info.size_file_comment<commentBufferSize)
		{
			*(szComment+file_info.size_file_comment)='\0';
			uSizeRead = file_info.size_file_comment;
		}
		else
			uSizeRead = commentBufferSize;

		if (lSeek!=0) {
			if (fseek(s->file,lSeek,SEEK_CUR)==0)
				lSeek=0;
			else
				err=UNZ_ERRNO;
		}
		if ((file_info.size_file_comment>0) && (commentBufferSize>0)) {
			if (fread(szComment,(uInt)uSizeRead,1,s->file)!=1)
				err=UNZ_ERRNO;
		}
		lSeek+=file_info.size_file_comment - uSizeRead;
	}
	else
		lSeek+=file_info.size_file_comment;

	if ((err==UNZ_OK) && (pfile_info!=NULL))
		*pfile_info=file_info;

	if ((err==UNZ_OK) && (pfile_info_internal!=NULL))
		*pfile_info_internal=file_info_internal;

	return err;
}



/*
  Write info about the ZipFile in the *pglobal_info structure.
  No preparation of the structure is needed
  return UNZ_OK if there is no problem.
*/
extern int unzGetCurrentFileInfo (	unzFile file, unz_file_info *pfile_info,
									char *szFileName, uLong fileNameBufferSize,
									void *extraField, uLong extraFieldBufferSize,
									char *szComment, uLong commentBufferSize)
{
	return unzlocal_GetCurrentFileInfoInternal(file,pfile_info,NULL,
												szFileName,fileNameBufferSize,
												extraField,extraFieldBufferSize,
												szComment,commentBufferSize);
}

/*
  Set the current file of the zipfile to the first file.
  return UNZ_OK if there is no problem
*/
extern int unzGoToFirstFile (unzFile file)
{
	int err=UNZ_OK;
	unz_s* s;
	if (file==NULL)
		return UNZ_PARAMERROR;
	s=(unz_s*)file;
	s->pos_in_central_dir=s->offset_central_dir;
	s->num_file=0;
	err=unzlocal_GetCurrentFileInfoInternal(file,&s->cur_file_info,
											 &s->cur_file_info_internal,
											 NULL,0,NULL,0,NULL,0);
	s->current_file_ok = (err == UNZ_OK);
	return err;
}


/*
  Set the current file of the zipfile to the next file.
  return UNZ_OK if there is no problem
  return UNZ_END_OF_LIST_OF_FILE if the actual file was the latest.
*/
extern int unzGoToNextFile (unzFile file)
{
	unz_s* s;	
	int err;

	if (file==NULL)
		return UNZ_PARAMERROR;
	s=(unz_s*)file;
	if (!s->current_file_ok)
		return UNZ_END_OF_LIST_OF_FILE;
	if (s->num_file+1==s->gi.number_entry)
		return UNZ_END_OF_LIST_OF_FILE;

	s->pos_in_central_dir += SIZECENTRALDIRITEM + s->cur_file_info.size_filename +
			s->cur_file_info.size_file_extra + s->cur_file_info.size_file_comment ;
	s->num_file++;
	err = unzlocal_GetCurrentFileInfoInternal(file,&s->cur_file_info,
											   &s->cur_file_info_internal,
											   NULL,0,NULL,0,NULL,0);
	s->current_file_ok = (err == UNZ_OK);
	return err;
}

/*
  Get the position of the info of the current file in the zip.
  return UNZ_OK if there is no problem
*/
extern int unzGetCurrentFileInfoPosition (unzFile file, unsigned long *pos )
{
	unz_s* s;	

	if (file==NULL)
		return UNZ_PARAMERROR;
	s=(unz_s*)file;

	*pos = s->pos_in_central_dir;
	return UNZ_OK;
}

/*
  Set the position of the info of the current file in the zip.
  return UNZ_OK if there is no problem
*/
extern int unzSetCurrentFileInfoPosition (unzFile file, unsigned long pos )
{
	unz_s* s;	
	int err;

	if (file==NULL)
		return UNZ_PARAMERROR;
	s=(unz_s*)file;

	s->pos_in_central_dir = pos;
	err = unzlocal_GetCurrentFileInfoInternal(file,&s->cur_file_info,
											   &s->cur_file_info_internal,
											   NULL,0,NULL,0,NULL,0);
	s->current_file_ok = (err == UNZ_OK);
	return UNZ_OK;
}

/*
  Try locate the file szFileName in the zipfile.
  For the iCaseSensitivity signification, see unzipStringFileNameCompare

  return value :
  UNZ_OK if the file is found. It becomes the current file.
  UNZ_END_OF_LIST_OF_FILE if the file is not found
*/
extern int unzLocateFile (unzFile file, const char *szFileName, int iCaseSensitivity)
{
	unz_s* s;	
	int err;

	
	uLong num_fileSaved;
	uLong pos_in_central_dirSaved;


	if (file==NULL)
		return UNZ_PARAMERROR;

    if (strlen(szFileName)>=UNZ_MAXFILENAMEINZIP)
        return UNZ_PARAMERROR;

	s=(unz_s*)file;
	if (!s->current_file_ok)
		return UNZ_END_OF_LIST_OF_FILE;

	num_fileSaved = s->num_file;
	pos_in_central_dirSaved = s->pos_in_central_dir;

	err = unzGoToFirstFile(file);

	while (err == UNZ_OK)
	{
		char szCurrentFileName[UNZ_MAXFILENAMEINZIP+1];
		unzGetCurrentFileInfo(file,NULL,
								szCurrentFileName,sizeof(szCurrentFileName)-1,
								NULL,0,NULL,0);
		if (unzStringFileNameCompare(szCurrentFileName,
										szFileName,iCaseSensitivity)==0)
			return UNZ_OK;
		err = unzGoToNextFile(file);
	}

	s->num_file = num_fileSaved ;
	s->pos_in_central_dir = pos_in_central_dirSaved ;
	return err;
}


/*
  Read the static header of the current zipfile
  Check the coherency of the static header and info in the end of central
        directory about this file
  store in *piSizeVar the size of extra info in static header
        (filename and size of extra field data)
*/
static int unzlocal_CheckCurrentFileCoherencyHeader (unz_s* s, uInt* piSizeVar,
													uLong *poffset_local_extrafield,
													uInt *psize_local_extrafield)
{
	uLong uMagic,uData,uFlags;
	uLong size_filename;
	uLong size_extra_field;
	int err=UNZ_OK;

	*piSizeVar = 0;
	*poffset_local_extrafield = 0;
	*psize_local_extrafield = 0;

	if (fseek(s->file,s->cur_file_info_internal.offset_curfile +
								s->byte_before_the_zipfile,SEEK_SET)!=0)
		return UNZ_ERRNO;


	if (err==UNZ_OK) {
		if (unzlocal_getLong(s->file,&uMagic) != UNZ_OK)
			err=UNZ_ERRNO;
		else if (uMagic!=0x04034b50)
			err=UNZ_BADZIPFILE;
	}
	if (unzlocal_getShort(s->file,&uData) != UNZ_OK)
		err=UNZ_ERRNO;
/*
	else if ((err==UNZ_OK) && (uData!=s->cur_file_info.wVersion))
		err=UNZ_BADZIPFILE;
*/
	if (unzlocal_getShort(s->file,&uFlags) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getShort(s->file,&uData) != UNZ_OK)
		err=UNZ_ERRNO;
	else if ((err==UNZ_OK) && (uData!=s->cur_file_info.compression_method))
		err=UNZ_BADZIPFILE;

    if ((err==UNZ_OK) && (s->cur_file_info.compression_method!=0) &&
                         (s->cur_file_info.compression_method!=Z_DEFLATED))
        err=UNZ_BADZIPFILE;

	if (unzlocal_getLong(s->file,&uData) != UNZ_OK) /* date/time */
		err=UNZ_ERRNO;

	if (unzlocal_getLong(s->file,&uData) != UNZ_OK) /* crc */
		err=UNZ_ERRNO;
	else if ((err==UNZ_OK) && (uData!=s->cur_