Protecting Special Characters in Query String in PHP

Q

How To Protect Special Characters in Query String in PHP?

✍: FYIcenter.com

A

If you want to include special characters like spaces in the query string, you need to protect them by applying the urlencode() translation function. The script below shows how to use urlencode():

<?php
  print("<html>");
  print("<p>Please click the links below"
    ." to submit comments about FYICenter.com:</p>");
  $comment = 'I want to say: "It\'s a good site! :->"';
  $comment = urlencode($comment);
  print("<p>"
    ."<a href=\"processing_forms.php?name=Guest&comment=$comment\">"
    ."It's an excellent site!</a></p>");
  $comment = 'This visitor said: "It\'s an average site! :-("';
  $comment = urlencode($comment);
  print("<p>"
    .'<a href="/processing_forms.php?'.$comment.'">'
    ."It's an average site.</a></p>");
  print("</html>");
?>

If you copy this script as submit_comments.php to your Web server, and click the first link, you will get:

  query_string = name=Guest&comment=
    I+want+to+say%3A+%22It%27s+a+good+site%21+%3A-%3E%22
Number of values: 2
  name = Guest
  comment = I want to say: "It's a good site! :->"

If you click the second link, you will get:

  query_string 
    = This+visitor+said%3A+%22It%27s+an+average+site%21+%3A-%28%22
Number of values: 1
  This_visitor_said:_\"It\'s_an_average_site!_:-(\" =

Now you know that urlencode() all special characters into HEX numbers. To translate them back, you need to apply urldecode().

⇒ Supporting a Multiple-Page Form in PHP

⇐ Retrieving the Original Query String in PHP

⇑ Processing Web Forms in PHP

⇑⇑ PHP Tutorials

2022-09-09, ∼6645🔥, 1💬

Submitting Values without Using a Form in PHP
How To Submit Values without Using a Form in PHP? If you know the values you want to submit, you can code the values in a hyper link at the end of the URL. The additional values provided at the end of a URL is called query string. There are two suggestions on how to use query strings to submit value... 2016-11-08, ∼4243🔥, 0💬

Supporting Hidden Form Fields in PHP
How To Support Hidden Form Fields in PHP? Hidden fields are special fields in a form that are not shown on the Web page. But when the form is submitted, values specified in the hidden fields are also submitted to the Web server. A hidden field can be specified with the <INPUT TYPE=HIDDEN ...&... 2016-11-08, ∼3712🔥, 0💬

Supporting a Multiple-Page Form in PHP
How To Support Multiple-Page Forms in PHP? If you have a long form with a lots of fields, you may want to divide the fields into multiple groups and present multiple pages with one group of fields on one page. This makes the a long form more user-friendly. However, this requires you to write good sc... 2016-11-05, ∼3477🔥, 0💬

Understanding and Managing Cookies in PHP
Where to find tutorials on how to manage Cookies in PHP? A collection of tutorials to answer many frequently asked questions how to manage Cookies in PHP. Clear explanations and tutorial exercises are provided on setting and receiving cookies, creating and removing persistent cookies, specifying dom... 2016-11-05, ∼3351🔥, 0💬

Generating and Processing Form with the Same Script in PHP
How To Generate and Process a Form with the Same Script in PHP? In previous exercises, a Web form is generated by one script, and processed by another script. But you could write a single script to do both. You just need to remember to: Use same script name as the form generation script in the "acti... 2016-11-08, ∼3185🔥, 0💬

Supporting Multiple Submit Buttons in PHP
How To Support Multiple Submit Buttons in PHP? Sometimes, you may need to give visitors multiple submit buttons on a single form to allow them to submit the form for different purposes. For example, when you show your customer a purchase order in a Web form, you may give your customer 3 submit butto... 2016-11-08, ∼2920🔥, 0💬

What Is a Cookie in PHP
What Is a Cookie in PHP? A cookie is a small amount of information sent by a Web server to a web browser and then sent back unchanged by the browser each time it accesses that server. HTTP cookies are used for authenticating, tracking, and maintaining specific information about users, such as site p... 2016-11-05, ∼2865🔥, 0💬

Receiving a Cookie from the Browser in PHP
How To Receive a Cookie from the Browser in PHP? If you know that a cookie has been sent to the browser when it was visiting the server previously, you can check the built-in $_COOKIE array, which contains all cookies that were sent by the server previously. The script below shows you how to pickup ... 2016-11-04, ∼2835🔥, 0💬

Sending a Cookie to the Browser in PHP
How To Send a Cookie to the Browser in PHP? If you want to sent a cookie to the browser when it comes to request your PHP page, you can use the setcookie( ) function. Note that you should call setcookie() function before any output statements. The following script shows you how to set cookies: &... 2016-11-04, ∼2685🔥, 0💬

All rights in the contents of this web site are reserved by the individual author. fyicenter.com does not guarantee the truthfulness, accuracy, or reliability of any contents.