text: #ifndef _ZNZLIB_H_
  #define _ZNZLIB_H_
  
  /*
  znzlib.h  (zipped or non-zipped library)
  
  *****            This code is released to the public domain.            *****
  
  *****  Author: Mark Jenkinson, FMRIB Centre, University of Oxford       *****
  *****  Date:   September 2004                                           *****
  
  *****  Neither the FMRIB Centre, the University of Oxford, nor any of   *****
  *****  its employees imply any warranty of usefulness of this software  *****
  *****  for any purpose, and do not assume any liability for damages,    *****
  *****  incidental or otherwise, caused by any use of this document.     *****
  
  */
  
  /*
  
  This library provides an interface to both compressed (gzip/zlib) and
  uncompressed (normal) file IO.  The functions are written to have the
  same interface as the standard file IO functions.
  
  To use this library instead of normal file IO, the following changes
  are required:
   - replace all instances of FILE* with znzFile
   - change the name of all function calls, replacing the initial character
     f with the znz  (e.g. fseek becomes znzseek)
   - add a third parameter to all calls to znzopen (previously fopen)
     that specifies whether to use compression (1) or not (0)
   - use znz_isnull rather than any (pointer == NULL) comparisons in the code
  
  NB: seeks for writable files with compression are quite restricted
  
  */
  
  
  /*=================*/
  #ifdef  __cplusplus
  extern "C" {
  #endif
     /*=================*/
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <stdarg.h>
  
     /* include optional check for HAVE_FDOPEN here, from deleted config.h:
  
        uncomment the following line if fdopen() exists for your compiler and
        compiler options
     */
     /* #define HAVE_FDOPEN */
  
  
  #ifdef HAVE_ZLIB
  #if defined(ITKZLIB)
  #include "itk_zlib.h"
  #else
  #include "zlib.h"
  #endif
  #endif
  
  
     struct znzptr
     {
        int withz;
        FILE* nzfptr;
  #ifdef HAVE_ZLIB
        gzFile zfptr;
  #endif
     } ;
  
     /* the type for all file pointers */
     typedef struct znzptr * znzFile;
  
  
     /* int znz_isnull(znzFile f); */
     /* int znzclose(znzFile f); */
  #define znz_isnull(f) ((f) == NULL)
  #define znzclose(f)   Xznzclose(&(f))
  
     /* Note extra argument (use_compression) where
        use_compression==0 is no compression
        use_compression!=0 uses zlib (gzip) compression
     */
  
     znzFile znzopen(const char *path, const char *mode, int use_compression);
  
     znzFile znzdopen(int fd, const char *mode, int use_compression);
  
     int Xznzclose(znzFile * file);
  
     size_t znzread(void* buf, size_t size, size_t nmemb, znzFile file);
  
     size_t znzwrite(const void* buf, size_t size, size_t nmemb, znzFile file);
  
     long znzseek(znzFile file, long offset, int whence);
  
     int znzrewind(znzFile stream);
  
     long znztell(znzFile file);
  
     int znzputs(const char *str, znzFile file);
  
     char * znzgets(char* str, int size, znzFile file);
  
     int znzputc(int c, znzFile file);
  
     int znzgetc(znzFile file);
  
  #if !defined(WIN32)
     int znzprintf(znzFile stream, const char *format, ...);
  #endif
  
     /*=================*/
  #ifdef  __cplusplus
  }
  #endif
  /*=================*/
  
  #endif
  