[Resolved] letters only in text input

[helz]

does anyone know of some code that checks a text input to see if they have only entered letters of the alphabet.. and maybe special chars like _ and stuff. easy to do when using array, im not sure how to do it

[stolzyboy]

found this at php.net, may be useful for you, i found it on this page

[man]is_numeric[/man]

<?php
/* This function is not useful if you want
to check that someone has filled in only
numbers into a form because for example
4e4 and 444 are both "numeric".

I used a regular expression for this problem
and it works pretty good. Maybe it is a good
idea to write a function and then to use it.

$input_number = "444"; // Answer 1 
$input_number = "44 "; // Answer 2
$input_number = "4 4"; // Answer 2
$input_number = "4e4"; // Answer 2 
$input_number = "e44"; // Answer 2
$input_number = "e4e"; // Answer 2
$input_number = "abc"; // Answer 2
*/
$input_number = "444";

if (preg_match ("/^([0-9]+)$/", $input_number)) {
     print "Answer 1";
} else {
     print "Answer 2";
}
?> 

[helz]

thanks im sure it will become very useful..
did some searching on php.net but didnt turn up much

in that preg_match
it looked similar to the perl thing i found while roaming google:

unless ($test =~ /^(\w|\s)+$/) { print "error"; }

so ill check the preg_match thing on php.net to see if i can do it that way

[stolzyboy]

well that is what preg stands for: perl regular expressions

[helz]

ah koolio, so this is a noobie question:
would i be able to use the perl thing:
~ /^(\w|\s)+$/)
inside preg_match() ?
in the thread about the perl thing theres a post that explains what each part represents.

[stolzyboy]

i would think so... don't use preg much so wouldn't know for sure

[helz]

on the php.net/preg_match the user comments show some of the things in the perl post, so ill test it and see...

[laserlight]

In this case, [man]ctype_alpha/man would be more applicable.

hmm... but if you're using it to check for special characters as well, regex might be easier, not sure about the time difference.

[helz]

god dammit, theres like no where to go on the internet for this, apart from here of course 🙂 its like no-one has ever had a login/register page where you can only enter in letters, numbers or underscore

the things i want to be allowed:
abcdefghijklmnopqrstuvwxyz
0123456789
_

[helz]

woo nice one stolzyboy

that post about the number thingy worked!! i just converted it to use text or numbers (btw text includes _ automatically)

heres the final code for the rest of people with the same problem:

<?
$text = $_POST['text'];
$test = preg_match("/^(\w+)$/",$text);
echo $test;
	if ($test==0) {
	echo "(BAD) Your text input contained none-allowed characters";
	} elseif ($test==1) {
	echo "(GOOD) Your text input only contained the alphabet, digits, and underscore!<br>$text";
	}
} else {
echo "<form action='test2.php' method='POST'>
	  Enter Here: <input type='text' name='text'><br>
	  <input type='submit' value='submit'>";
}
?>

even though there isnt a \d (digits) it still accepts them with or without letters.

so current thing is all letters, digits and underscore, nothing else,
i havn't tried spaces yet

===edit===
tried spaces, they dont let them either WOO
works perfectly, now to integrate it into my login/register script!!