Opens a gzip (.gz) file for reading or writing.
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.
filename
The file name.
mode
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.)
use_include_path
You can set this optional parameter to 1, if you want to search for the file in the include_path too.