at_eof
if (last && at_eof())
int at_eof(void);
if (at_eof(&z->s)) return e("no SOF", "Corrupt JPEG");
while (!at_eof(&j->s)) {
if (at_eof(s)) return epuc("bad file","PIC file too short");
if (at_eof(s)) return epuc("bad file","file too short (reading packets)");
if (at_eof(s)) return epuc("bad file","file too short (pure read count)");
if (at_eof(s)) return epuc("bad file","file too short (mixed read count)");
if (at_eof(s)) return epuc("bad file","file too short (pic header)");
while (!at_eof(z) && c != '\n') {
while (!at_eof(z) && get8(z) != '\n')