HelenOS sources

FS_VUID_MAXLEN     69 uspace/lib/c/include/ipc/vfs.h 	char vuid[FS_VUID_MAXLEN + 1];
FS_VUID_MAXLEN     69 uspace/lib/posix/include/libc/ipc/vfs.h 	char vuid[FS_VUID_MAXLEN + 1];
HelenOS homepage, sources at GitHub