Dir_FindFilei
path = Dir_FindFilei(arg->s, arg->e, defaultPath);
#define Dir_FindFile(n, p) Dir_FindFilei(n, strchr(n, '\0'), p)
dirpath = Dir_FindFilei(word, slash+1, path);
fullname = Dir_FindFilei(file, efile, userIncludePath);
fullname = Dir_FindFilei(file, efile, defaultPath);
return Dir_FindFilei(file, efile, systemIncludePath);