format_unsigned
r += ", st_dev = " + format_unsigned(s.st_dev);
r += ", st_ino = " + format_unsigned(s.st_ino);
r += ", st_nlink = " + format_unsigned(s.st_nlink);
r += ", st_uid = " + format_unsigned(s.st_uid);
r += ", st_gid = " + format_unsigned(s.st_gid);
r += ", st_blksize = " + format_unsigned(s.st_blksize);
r += ", st_type = " + format_unsigned(s.st_type);
r += ", st_blocks = " + format_unsigned(s.st_blocks);
string format_unsigned(uint32 value);