Actually I typed all the code in my editor and either copied the specified font in the server folder. I had no issue with sha or session lines. But when I try to run the script in the browser, it shows nothing except a missing image place holder. I tried various browsers but it didn't work either.
So I tried to make some changes in original code so the "imagepng" function create a file from image inside memory and disabled the header line of code; It works!
Here is my new code:
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<?php
session_start();
// Set some important CAPTCHA constants
define('CAPTCHA_NUMCHARS', 6); // number of characters in pass-phrase
define('CAPTCHA_WIDTH', 150); // width of image
define('CAPTCHA_HEIGHT', 50); // height of image
// Generate the random pass-phrase
$pass_phrase = "";
for ($i = 0; $i < CAPTCHA_NUMCHARS; $i++) {
$pass_phrase .= chr(rand(97, 122));
}
// Store the encrypted pass-phrase in a session variable
$_SESSION['pass_phrase'] = sha1($pass_phrase);
// Create the image
$img = imagecreatetruecolor(CAPTCHA_WIDTH, CAPTCHA_HEIGHT);
// Set a white background with black text and gray graphics
$bg_color = imagecolorallocate($img, 255, 255, 255); // white
$text_color = imagecolorallocate($img, 0, 0, 0); // black
$graphic_color = imagecolorallocate($img, 64, 64, 64); // dark gray
// Fill the background
imagefilledrectangle($img, 0, 0, CAPTCHA_WIDTH, CAPTCHA_HEIGHT, $bg_color);
// Draw some random lines
for ($i = 0; $i < 5; $i++) {
imageline($img, 0, rand() % CAPTCHA_HEIGHT, CAPTCHA_WIDTH, rand() % CAPTCHA_HEIGHT, $graphic_color);
}
// Sprinkle in some random dots
for ($i = 0; $i < 50; $i++) {
imagesetpixel($img, rand() % CAPTCHA_WIDTH, rand() % CAPTCHA_HEIGHT, $graphic_color);
}
// Draw the pass-phrase string
imagettftext($img, 30, 0, 5, CAPTCHA_HEIGHT - 7, $text_color, "Courier New Bold.ttf", $pass_phrase);
// Output the image as a PNG using a header
//header("Content-type: image/png");
imagepng($img, "captcha.png");
echo '<img src="captcha.png" />';
// Clean up
imagedestroy($img);
?>
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But I want the script to be self-contained and could be called in the future lessons of book.
I think there is something wrong whit the header. Anybody can help me?
Thank you
