opt_t
extern opt_t *op;
opt_t opt;
opt_t *op;
char *opt_f, *opt_t;
opt_f = opt_t = strdup("");
strcmp(opt_t, "") != 0) {
opt_t = strdup(optarg);
if ((strcmp(opt_f, "") == 0) && (strcmp(opt_t, "") == 0))
do_conv(stdin, opt_f, opt_t, opt_s, opt_c);
do_conv(fp, opt_f, opt_t, opt_s,
static enum opt_t Option;