198 #define read1(in) (in->left == 0 ? readmore(in) : 0, \  macro
227     val = read1(in);  in read4()
228     val += (unsigned)read1(in) << 8;  in read4()
229     val += (unsigned long)read1(in) << 16;  in read4()
230     val += (unsigned long)read1(in) << 24;  in read4()
240     if (read1(in) != 31 || read1(in) != 139) bye(in->name, " not a gzip file");  in gzheader()
241     if (read1(in) != 8) bye("unknown compression method in", in->name);  in gzheader()
242     flags = read1(in);  in gzheader()
246         n = read1(in);  in gzheader()
247         n += (unsigned)(read1(in)) << 8;  in gzheader()
250     if (flags & 8) while (read1(in) != 0) ;  in gzheader()
251     if (flags & 16) while (read1(in) != 0) ;  in gzheader()