Cat
Cat(s, "");
Cat(path, s);
Cat(tilde, s);
Cat(s, ""); /* "nonomatch" is set */
Cat(path, "");
Cat(tilde, tpathp);
Cat(path, dp->d_name);
Cat(tilde, tpathp);
static void Cat(char *s1, char *s2);
Cat(path, "");
Cat(tilde, tpathp);
e = newexpr(Cat, 0, e, f);
case Cat:
if (e->type == Cat) {
case Cat:
case Cat:
case Cat: