php filters

1# sanitize form data
2function clean($data)
3{
4    $data = htmlspecialchars($data);
5    $data = stripslashes($data);
6    $data = trim($data);
7    return $data;
8}

1#Filter Validation
2
3<?php
4    //checks for posted data
5    /*
6    if(filter_has_var(INPUT_POST,'data')){
7        echo 'Data Found';
8    }else{
9        echo 'No Data';
10    }
11    */
12    if(filter_has_var(INPUT_POST,'data')){
13        //remove illegal chars
14        $email = $_POST['data'];
15        $email = filter_var($email, FILTER_SANITIZE_EMAIL);
16        echo $email.'<br>';
17
18     //validate as an email address
19     if(filter_input(INPUT_POST, 'data', FILTER_VALIDATE_EMAIL)){
20        echo 'Email is Valid';
21     }else{
22        echo 'Email is not Valid';
23     }
24    
25     //we can use the below if we use the sanatizer above
26     if(filter_var($email, FILTER_VALIDATE_EMAIL)){
27        echo 'Email is Valid';
28     }else{
29        echo 'Email is not Valid';
30    }
31}
32    #Other Validations
33    #FILTER_VALIDATE_BOOLEAN
34    #FILTER_VALIDATE_EMAIL
35    #FILTER_VALIDATE_FLOAT
36    #FILTER_VALIDATE_INT
37    #FILTER_VALIDATE_IP
38    #FILTER_VALIDATE_REGEXP  'REGULAR EXPRESSION'
39    #FILTER_VALIDATE_URL
40
41    #Other sanatizes
42    #FILTER_SANATIZE_EMAIL
43    #FILTER_SANATIZE_ENCODED
44    #FILTER_SANATIZE_NUMBER_FLOAT
45    #FILTER_SANATIZE_NUMBER_INT
46    #FILTER_SANATIZE_SPECIAL_CHARS
47    #FILTER_SANATIZE_STRING
48    #FILTER_SANATIZE_URL
49
50    //EXAMPLE int VALIDATION
51    $var = 'john';
52    if(filter_var($var, FILTER_VALIDATE_INT)){
53        echo '<br>'.$var.' is a number<br>';
54    }else{
55        echo '<br>'.$var.' is not a number'.'<br>';
56    }
57
58    //EXAMPLE int Sanitazion
59    $var2 = '33k2dsdffgsdf3563sdf';
60    var_dump(filter_var($var2, FILTER_SANITIZE_NUMBER_INT));
61
62    //ARRAY USAGE
63    $filters = array(
64        "data" => FILTER_VALIDATE_EMAIL,
65        "data2" => array(
66            "filter" => FILTER_VALIDATE_INT,
67            "options" => array(
68                "min_range" => 1,
69                "max_range" => 100
70        )
71        )
72    );
73    print_r(filter_input_array(INPUT_POST, $filters));
74
75?>
76
77<form method ="post" action="<?php echo $_SERVER['PHP_SELF'];?>">
78    <input type="text" name="data">
79    <input type="text" name="data2">
80    <button type="submit">Submit</button>
81</form>