Form validate - numbers only

[Anon]

Beginner here:
Doing a search in php to a mysql database.

What code can I add to check to make sure that the input from the form is only numerals, no text characters ?

I found using:

if (!eregi("[[:alpha:]]", $search_query))
{
echo "Error: you have entered an invalid query, you can only use characters!<br>";
exit;
}

would do it for for text, but what is it for numerals ?

Thx

[cordex]

have you tried:

if (eregi("[^0-9]", $search_query))
{
echo "Error: you have entered an invalid query, you can only use the number thingies.<br>";
exit;
}

[amcgrath]

or the is_numeric() function....

[cordex]

damn, forgot about that.
I'd probably go with is_numeric()

UNLESS

you are concerned about decimals, hyphens (ie. negative numbers) or trailing whitespaces - all of which is_numeric ignores.

If you do decide to use the code I gave you, I'd convert it to preg:
if (preg_match("/[^0-9]/", $search_query))
{
echo "Error: you have entered an invalid query, you can only use characters!<br>";
exit;
}

-Ben

[Anon]

Wow, thanks for your help.

What if I wanted to search only part of what the form input was

I.E.

Input was 07950

but I wanted to show them the results from
079??

Thanks again!

[Anon]

Hmmm ... I'm not sure what you're looking for, but check out substr()