Filter Functions
Note that when using FILTER_VALIDATE_INT along with the FILTER_FLAG_ALLOW_HEX flag, the string "2f", for example, is not validated successfully, because you must use the "0x" prefix, otherwise, it treats the data as base 10.
The range options are also smart enough to recognize when the boundaries are exceeded in different bases.
Here's an example:
<?php
$foo = '256';
$bar = '0x100';
var_dump(validate_int($foo)); // false, too large
var_dump(validate_int($bar)); // false, too large
function validate_int($input)
{
return filter_var(
$input,
FILTER_VALIDATE_INT,
// We must pass an associative array
// to include the range check options.
array(
'flags' => FILTER_FLAG_ALLOW_HEX,
'options' => array('min_range' => 1, 'max_range' => 0xff)
)
);
}
?>
filter_var
(PHP 5 >= 5.2.0, PECL filter:0.11.0)
filter_var — Filters a variable with a specified filter
Parameters
- variable
-
Value to filter.
- filter
-
ID of a filter to use. Defaults to FILTER_SANITIZE_STRING.
- options
-
Associative array of options or bitwise disjunction of flags. If filter accepts options, flags can be provided in "flags" field of array. For the "callback" filter, callback type should be passed.
Return Values
Returns the filtered data, or FALSE if the filter fails.
Examples
Example #1 A filter_var() example
<?php
var_dump(filter_var('bob@example.com', FILTER_VALIDATE_EMAIL));
var_dump(filter_var('example.com', FILTER_VALIDATE_URL, FILTER_FLAG_SCHEME_REQUIRED));
?>
The above example will output:
string(15) "bob@example.com" bool(false)
add a note
User Contributed Notesfilter_var
dyer85 at gmail dot com
03-Nov-2008 02:00
03-Nov-2008 02:00
visseraj at gmail dot com
28-Aug-2008 10:31
28-Aug-2008 10:31
Here are the other possible flags that you can use:
http://us3.php.net/manual/hu/ref.filter.php
dale dot liszka at gmail dot com
09-Jul-2008 10:15
09-Jul-2008 10:15
Here is how to use multiple flags (for those who learn better by example, like me):
<?php
echo "|asdf".chr(9).chr(128)."_123|";
echo "\n";
// "bitwise conjunction" means logic OR / bitwise |
echo filter_var("|asdf".chr(9).chr(128)."_123\n|" ,FILTER_SANITIZE_STRING, FILTER_FLAG_STRIP_LOW | FILTER_FLAG_STRIP_HIGH);
/*
Results:
|asdf �_123|
|asdf_123|
*/
?>
dale dot liszka at gmail dot com
09-Jul-2008 09:54
09-Jul-2008 09:54
Using the FILTER_CALLBACK requires an array to be passed as the options:
<?php
function toDash($x){
return str_replace("_","-",$x);
}
echo filter_var("asdf_123",FILTER_CALLBACK,array("options"=>"toDash"));
// returns 'asdf-123'
?>
John
26-Jul-2007 12:35
26-Jul-2007 12:35
I managed to get this to work with PHP 5.1.6 on CentOS 5 with minor difficulty.
1) Download the PECL filter package
2) Extract the tarball
3) phpize the directory
4) ./configure
5) make
6) filter-0.11.0/logical_filters.c:25:31: error: ext/pcre/php_pcre.h: No such file or directory
7) find / -name php_pcre.h
8) Make sure php-devel is installed
9) Edit filter-0.11.0/logical_filters.c and replace "ext/pcre/php_pcre.h" with the absolute path of php_pcre.h
10) make
11) make install
12) add "extension=filter.so" to php.ini
13) Restart Apache