PHP Check if Many spaces before or after a string

Question

On my website, after a user registers they can change their username at any time. The minimum amount of characters is 6 and max amount is 25.

Here's some of the coding to check the length and remove characters:

$users_new_name = strip_tags($_POST['new_name']);
$new_name = preg_replace("/[^0-9a-zA-Z -]/", "", $users_new_name);
// Check Length
if (ctype_space($new_name)) {
$message = die('<span class="Fail">Error: Name Must Be At least 6 Characters Long!</i></span>');    
}
if(strlen($new_name) < 6) {
$message = die('<span class="Fail">Error: Name Must Be At least 6 Characters Long!</i></span>');
}
if(strlen($new_name) > 25) {
$message = die('<span class="Fail">Error: Name Can\'t Be More Than 25 Characters Long!</i></span>');
}

The issue I'm having is if you type in 5 spaces and then a letter or number, There new name will be that letter or number; Or if you type in a letter or number then 5 spaces. How could I prevent this from happening?

Here's a screenshot of the example enter image description here

Misunderstood · Accepted Answer · 2015-01-18 02:26:50Z

1

I do not understand why tags would be in a POST.

Spaces becomes a non-issue if you change:

$users_new_name = strip_tags($_POST['new_name']);

To

$users_new_name = trim(strip_tags($_POST['new_name']));

Or ideally (strip tags is unnecessary):

$users_new_name = trim($_POST['new_name']);

Change the RegEx expression to /[^0-9a-zA-Z]/ to eliminate spaces and dashes.

edited Jan 18, 2015 at 2:26

answered Jan 18, 2015 at 2:10

Misunderstood

5,6791 gold badge20 silver badges25 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

keji Over a year ago

@user3059258 this only removes spaces from the front and back

user3059258 Over a year ago

@Misunderstood That's what I needed was from the front and the back, The trim Worked Perfectly!

Misunderstood Over a year ago

The problem was also in the RegEx. It was saying spaces were allowed. [^ ] or [^x20] say to allow spaces. By removing the space dash. spaces and dashes would then be eliminated. /[^0-9a-zA-Z|x20|x2D]/ would have worked too.

Mikey · Accepted Answer · 2015-01-18 02:11:01Z

1

It sounds like you need trim() to trim any spaces from the username. See http://php.net/trim

ltrim() will trim any leading spaces. rtrim() will trim any spaces at the end of the string.

answered Jan 18, 2015 at 2:11

Mikey

215 bronze badges

5 Comments

user3059258 Over a year ago

That Worked Perfectly! But also, on the preg_replace Dashes aren't being removed, Not sure why!

Mikey Over a year ago

@user3059258 In that case I would adjust the preg_replace, or do a simple str_replace on the username to remove dashes.

keji Over a year ago

@user3059258 it'd because you added - at the end of the character block. For alphanumeric use "/[^0-9a-zA-Z ]/"

Mikey Over a year ago

To simply allow alphanumeric, copy the regex in @kdogisthebest's comment.

user3059258 Over a year ago

I changed it to: $new_name = preg_replace("/[^0-9a-zA-Z ]/", "", $users_new_name); $new_name .= preg_replace('-', '', $users_new_name); Works Fine now

MrMarlow · Accepted Answer · 2015-01-18 03:09:21Z

0

This is fairly simple and it's something I've had to deal with on systems before.

If you make the first thing you call, this preg_replace, the rest of you code should catch it;

$name = preg_replace('~[\s]+~', '', $name);

This simply checks if there is a space, or more than one, then replaces with a single space.

So " l" would return " l" - failing your 5 character minimum.

Use trim() around this and you should have it working to something acceptable (Depending on your definition of acceptable - worked in my use-case)

answered Jan 18, 2015 at 3:09

MrMarlow

8564 silver badges17 bronze badges

Collectives™ on Stack Overflow

PHP Check if Many spaces before or after a string

3 Answers 3

3 Comments

5 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

3 Comments

5 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related