gzprintf
ZEXTERN int ZEXPORTVA gzprintf(gzFile file, const char *format, ...);
ZEXTERN int ZEXPORTVA gzprintf();
if (gzprintf(file, ", %s!", "hello") != 8) {
ZEXTERN int ZEXPORTVA gzprintf(gzFile file, const char *format, ...);
ZEXTERN int ZEXPORTVA gzprintf();