tilde
if (tilde(tilded_dir, dir) == 0)
static Char *tilde(Char *, Char *);
r = (p[0] == EOS || p[0] == CHAR || p[0] == CSUBST) ? tilde(Xstring(ts, tp)) : (char *) 0;
static char *tilde ARGS((char *acp));
tilde = "";
tilde = "~";
tilde = cp1 = expbuf;
tilde = "";
Cat(tilde, s);
Cat(tilde, tpathp);
Cat(tilde, tpathp);
Cat(tilde, tpathp);
const char *tilde; /* "~user" if not expanding tilde, else "" */