How to do Validating and Sanitizing in PHP?

[michaels]

Hello Guys,
I have done some basic things in PHP, so I don't have enough knowledge about the PHP programming language. Recently I have started the topic of the filters. I understood the filters but I am unable to grab the validation and sanitization done by using the filters. Please tell me how to do Validating and Sanitizing in PHP? Reply me as soon as possible.!!

[Deabelos]

You should know that data validation is an integral part of working with forms. Using the filters are very important because an invalid submitted data may lead to security problems and also it can break your web-page. So I would like to recommend you to use the filters in your program to keep the web page safe. You can validate data by using the "filter_var" function. Validation is used to ensure that the data is strongly typed, correct syntax, within length boundaries, contains only permitted characters, or that numbers are correctly signed and within range boundaries.

[Warner]

While talking about validating and sanitizing, I am assuming that you are having knowledge about the filters. PHP has several built-in filter_* functions that can assist with validating and sanitizing email addresses, URLs, strings, integers, float values, etc. There are two kinds of filters :

• Validating filters
• Sanitizing filters

I normally tell people to eliminate or translate characters in an effort to make the input "safe".

[kyosang]

While learning about the filters, you should also have knowledge about an options and flags that are used to add additional filtering options to the specified filters. Different filters have different options and flags. The following sample of coding explains the validation of an integer using the filter_var() and the "min_range" and "max_range" options :

<?php
$var=500;

$int_options = array(
"options"=>array
  (
  "min_range"=>0,
  "max_range"=>456
  )
);

if(!filter_var($var, FILTER_VALIDATE_INT, $int_options))
  {
  echo("Integer is not valid");
  }
else
  {
  echo("Integer is valid");
  }

[Zecho]

You can validate your input from the form by using the following coding :

<?php
if(!filter_has_var(INPUT_GET, "email"))
  {
  echo("Input not Proper");
  }
else
  {
  if (!filter_input(INPUT_GET, "email", FILTER_VALIDATE_EMAIL))
    {
    echo "E-Mail is not valid";
    }
  else
    {
    echo "E-Mail is valid";
    }
  }
?>

In the example above, the input variable "email" is sent to the PHP page.