tigetnum
if (tigetnum(ta->ta_name) == -2) {
ta->ta_valp->at_val = tigetnum(ta->ta_name);
extern int tigetnum(const char *);
if ((i = tigetnum(cap)) >= -1) {
extern int tigetnum();
gl->nline = tigetnum((char *)"lines");
gl->ncolumn = tigetnum((char *)"cols");
else if ((i = tigetnum(*_argv)) != -2)