p_re
static void p_re(struct parse *p, int end1, int end2);
p_re(p, OUT, OUT);
p_re(p, ')', IGN);
p_re(p, '\\', ')');
errcode = regcomp(&p->p_re, p->p_key, REG_EXTENDED|REG_NOSUB);
regerror(errcode, &p->p_re, buf, sizeof(buf));
regfree(&p->p_re);
if (regexec(&p->p_re, key, 0, NULL, 0) == 0)
regex_t p_re; /* RE to match against pathname (malloc) */