DaniWeb Forum Index > Web Development > PHP

image verification problem

Please support our PHP advertiser: PostgreSQL or MySQL? Compare and contrast the two most popular open source databases

•

Join Date: Oct 2006

Posts: 4

Reputation: zodehala is an unknown quantity at this point

Solved Threads: 0

zodehala

Offline

Newbie Poster

image verification problem

Jul 16th, 2007

index.php

 Help with Code Tags 
 PHP Syntax (Toggle Plain Text) 
 <?php
 /*header*/
header("Content-Type: image/png");
 
/*We'll set this variable later.*/
$new_string;
 
/*register the session variable. */
session_register('new_string');
 
/*You will need these two lines below.*/
echo "<html><head><title>Verification</title></head>";
echo "<body>";
 
/* set up image, the first number is the width and the second is the height*/
$im = imageCreate(200, 40); 
 
/*creates two variables to store color*/
$white = imageColorAllocate($im, 255, 255, 255);
$black = imageColorAllocate($im, 0, 0, 0);
 
 
 
/*Runs the string through the md5 function*/
$string = md5(rand(0,9999)); 
 
/*creates the new string. */
$new_string = substr($string, 17, 5);
 
 /*fill image with black*/
imageFill($im, 0, 0, $black);
 
 /*writes string */
imageString($im, 4, 96, 19, $new_string, $white);
 
/* output to browser*/
imagePNG($im, "verify.png");
imageDestroy($im); 
 
?>
 <?php
 /*header*/
header("Content-Type: image/png");

/*We'll set this variable later.*/
$new_string;

/*register the session variable. */
session_register('new_string');

/*You will need these two lines below.*/
echo "<html><head><title>Verification</title></head>";
echo "<body>";

/* set up image, the first number is the width and the second is the height*/
$im = imageCreate(200, 40); 

/*creates two variables to store color*/
$white = imageColorAllocate($im, 255, 255, 255);
$black = imageColorAllocate($im, 0, 0, 0);



/*Runs the string through the md5 function*/
$string = md5(rand(0,9999)); 

/*creates the new string. */
$new_string = substr($string, 17, 5);

 /*fill image with black*/
imageFill($im, 0, 0, $black);

 /*writes string */
imageString($im, 4, 96, 19, $new_string, $white);

/* output to browser*/
imagePNG($im, "verify.png");
imageDestroy($im); 

?>

formhandler.php

 Help with Code Tags 
 PHP Syntax (Toggle Plain Text) 
<?php
 
/*This starts the session that we created on the last page*/
session_start(); 
 
 
/*This trims the random variable of any white space that the user may have unknowingly put in.*/
$random = trim($random);
 
/*Below is a conditional statement: In English it reads, if the string that the user put into the text box is equal to what is in the image then print to the screen, "You are verified."  If they are not equal it tells the user to go back and try again.*/
 
/*We can use the variable $new_string because we registered it into our session on the last page, it retains its value that it had on the first page.*/
if ($new_string == $random){
echo "You are verified";
}
else{
echo "Please go back and get verified.";
}
 
 
/*I plugged our image in like I would any other image.*/
echo "<img src=\"verify.png\">";
echo "<br><br>";
echo "Type the code you see in the image in the box below. (case sensitive)";
echo " <form action=\"formhandler.php\" method=post>";
echo "<input name=\"random\" type=\"text\" value=\"\">";
echo "<input type=\"submit\">";
echo "</form>";
echo "</body>";
echo "</html>";
 
?>
<?php

/*This starts the session that we created on the last page*/
session_start(); 


/*This trims the random variable of any white space that the user may have unknowingly put in.*/
$random = trim($random);

/*Below is a conditional statement: In English it reads, if the string that the user put into the text box is equal to what is in the image then print to the screen, "You are verified."  If they are not equal it tells the user to go back and try again.*/

/*We can use the variable $new_string because we registered it into our session on the last page, it retains its value that it had on the first page.*/
if ($new_string == $random){
echo "You are verified";
}
else{
echo "Please go back and get verified.";
}


/*I plugged our image in like I would any other image.*/
echo "<img src=\"verify.png\">";
echo "<br><br>";
echo "Type the code you see in the image in the box below. (case sensitive)";
echo " <form action=\"formhandler.php\" method=post>";
echo "<input name=\"random\" type=\"text\" value=\"\">";
echo "<input type=\"submit\">";
echo "</form>";
echo "</body>";
echo "</html>";

?>

why does it give error?

http://img412.imageshack.us/img412/9467/ivxb3.gif

this tutorial is in http://www.phpnoise.com/tutorials/1/1

Last edited by zodehala; Jul 16th, 2007 at 12:03 pm.

•

Join Date: Jul 2007

Posts: 21

Reputation: dezignwork is an unknown quantity at this point

Solved Threads: 2

dezignwork dezignwork is offline

Offline

Newbie Poster

Re: image verification problem

Jul 17th, 2007

if you deal with the session initialization before you send headers to the browser then you shouldn't have this error.

If you want to use the following:
/*header*/
header("Content-Type: image/png");

then you could store this in image.php and then call it like:

<img src="image.php" border="0" />

I hope that helps.

tim

hosting :: development :: design
dezignwork.com