pset4 recover can't find more than one jpg

Question

I'm doing pset4 recover program. I've written following code to read 512 bytes of data at once and detect the start of any jpg image

BYTE buffer[512];

while((fread(buffer, 512 * sizeof(BYTE), 1, CFcard)) == 1)
{
    if ((buffer[0] == 0xff) && (buffer[1] == 0xd8) && (buffer[2] == 0xff) && ((buffer[3] == 0xe0) || (buffer[3] == 0xe1)))
    {
        printf(".jpg\n");

where BYTE is typedef of uint8_t. But after executing the program it prints only one ".jpg" in the terminal console window. So, I want to know whether my condition is correct to determine the start of jpg image.

Thank you.