note that the two flag types have been split into an o_flags (for fcntl-like openflags) and o_modes where the latter shall carry the zzip_flags and possibly accessmodes for unix filesystems. Since this version of zziplib can not write zipfiles, it is not yet used for anything else than zzip-specific modeflags.

The zzip_open_ext_io function returns a new zzip-handle (use zzip_close to return it). On error the zzip_open_ext_io function will return null setting errno(3).

If any ext_io handlers were used then the referenced structure should be static as the allocated ZZIP_FILE does not copy them.

The zzip_open_shared_io function takes an extra stream argument - if a handle has been then ext/io can be left null and the new stream handle will pick up the ext/io. This should be used only in specific environment however since zzip_file_real does not store any ext-sequence.

The benefit for the zzip_open_shared_io function comes in when the old file handle was openened from a file within a zip archive. When the new file is in the same zip archive then the internal zzip_dir structures will be shared. It is even quicker, as no check needs to be done anymore trying to guess the zip archive place in the filesystem, here we just check whether the zip archive's filepath is a prefix part of the filename to be opened.

Note that the zzip_open_shared_io function is also used by zzip_freopen that will unshare the old handle, thereby possibly closing the handle.

The zzip_open_shared_io function returns a new zzip-handle (use zzip_close to return it). On error the zzip_open_shared_io function will return null setting errno(3).