Filter_input () function

Definition and usage

The filter_input () function obtains and filters the input from outside the script.

This function is used to verify variables from unsafe sources, such as user input.

This function can obtain input from various sources:

• Input_get
• Input_post
• Input_cookie
• Input_env
• Input_server
• Input_session (not yet implemented)
• Input_request (not yet implemented)

If the operation succeeds, the filtered data is returned. If the operation fails, false is returned.VariableIf the parameter is not set, null is returned.

Syntax

filter_input(input_type, variable, filter, options)

Parameters	Description
Input_type	Required. Specifies the input type. See the possible types in the list above.
Variable	Specifies the variable to be filtered.
Filter	Optional. Specifies the ID of the filter to be used. The default value is filter_sanitize_string. See the complete PHP filter function reference manual to obtain possible filters. The filter ID can be an ID name (such as filter_validate_email) or an ID (such as 274 ).
Options	Specifies an array containing flag/option. Check the possible flags and options of each filter.

 

 

 

 

 

 

In this example, we use the filter_input () function to filter a post variable. The accepted post variable is a valid email address.

<?phpif (!filter_input(INPUT_POST, ‘email‘, FILTER_VALIDATE_EMAIL)) { echo "E-Mail is not valid"; }else { echo "E-Mail is valid"; }?>

The output is similar:

E-Mail is valid

Filter Function

It is used to verify and filter data from non-security sources (such as user input.

The filter function is a core component of PHP. These functions can be used without installation.

PHP: indicates the earliest PHP version that supports this function.

Function	Description	PHP
Filter_has_var ()	Check whether a variable of the specified input type exists.	5
Filter_id ()	Returns the ID of the specified filter.	5
Filter_input ()	Obtain and filter the input from outside the script.	5
Filter_input_array ()	Obtain multiple inputs from outside the script and filter them out.	5
Filter_list ()	Returns an array containing all the supported filters.	5
Filter_var_array ()	Obtain and filter multiple variables.	5
Filter_var ()	Obtain and filter a variable.	5

ID	Description
Filter_callback	You can call a user-defined function to filter data.
Filter_sanitize_string	Remove tags, remove or encode special characters.
Filter_sanitize_stripped	The alias of the "string" filter.
Filter_sanitize_encoded	URL-encode string to remove or encode special characters.
Filter_sanitize_special_chars	HTML Escape Character '"<> & characters with ASCII values smaller than 32.
Filter_sanitize_email	Delete all characters except letters, numbers, and! # $ % & '* +-/=? ^ _ '{|} [Email protected] []
Filter_sanitize_url	Delete all characters except letters, numbers, and $-_. +! * '(), {}|\\^ ~ [] '<> # % ";/? : @ & =
Filter_sanitize_number_int	Delete all characters except numbers and +-
Filter_sanitize_number_float	Delete all characters except numbers, +-, and., ee.
Filter_sanitize_magic_quotes	Use the addslashes () (addslashes () function to add backslashes for escape ).
Filter_unsafe_raw	Do not filter, remove, or encode special characters.
Filter_validate_int	The value is verified by an integer in the specified range.
Filter_validate_boolean	If it is "1", "true", "on", and "yes", true is returned. If it is "0", "false", "off ", "No" and "", false is returned. Otherwise, null is returned.
Filter_validate_float	Verify the value with a floating point number.
Filter_validate_regexp	Verify the value based on Regexp and Perl-Compatible Regular Expressions.
Filter_validate_url	Use the value as the URL for verification.
Filter_validate_email	Use the value as email for verification.
Filter_validate_ip	Use the value as the IP address for verification.