zlib: PHP 4.0.4 - PHP 4.2.3 (systems with fopencookie only)
compress.zlib:// and compress.bzip2:// PHP 4.3.0 and up
- zlib: 
- compress.zlib:// 
- compress.bzip2:// 
 
   zlib: works like gzopen(), except that the
   stream can be used with fread() and the other
   filesystem functions.  This is deprecated as of PHP 4.3.0 due
   to ambiguities with filenames containing ':' characters; use
   compress.zlib:// instead.
  
   compress.zlib:// and
   compress.bzip2:// are equivalent to
   gzopen() and bzopen()
   respectively, and operate even on systems that do not support
   fopencookie.
  
   
Table M-7. Wrapper Summary
| Attribute | Supported | 
|---|
| Restricted by allow_url_fopen. | No | 
| Allows Reading | Yes | 
| Allows Writing | Yes | 
| Allows Appending | Yes | 
| Allows Simultaneous Reading and Writing | No | 
| Supports stat() | No, use the normal file:// wrapper 
        to stat compressed files. | 
| Supports unlink() | No, use the normal file:// wrapper 
        to unlink compressed files. | 
| Supports rename() | No | 
| Supports mkdir() | No | 
| Supports rmdir() | No |