gzopen() can be used to read a file which is
not in gzip format; in this case gzread() will
directly read from the file without decompression.
The file name.
As in fopen() (rb or
wb) but can also include a compression level
(wb9) or a strategy: f for
filtered data as in wb6f, h for
Huffman only compression as in wb1h.
(See the description of deflateInit2 in zlib.h for
more information about the strategy parameter.)
You can set this optional parameter to 1, if you
want to search for the file in the include_path too.
Returns a file pointer to the file opened, after that, everything you read
from this file descriptor will be transparently decompressed and what you
write gets compressed.