gzopen
ZEXTERN gzFile ZEXPORT gzopen(const char *, const char *);
file = gzopen(fname, "rb");
file = gzopen(fname, "wb");
out = gzopen(outfile, mode);
in = gzopen(infile, "rb");
file = gzopen(*argv, "rb");
ZEXTERN gzFile ZEXPORT gzopen(const char *, const char *);