Remove all non digit characters

[xxarmoxx]

How can I take a string and remove all non digit characters from the string? Unfortunately my regex skills arent so hot :(

[xxarmoxx]

This seems to be working well:

$str = "1234567890abc!@#$%^&*()-=_+[]{}|\\'\"?/><,.";
echo preg_replace("%[^0-9]%", "", $str);

Any objections?

[penagate]

No objections. You can use \d as well as 0-9.

[xxarmoxx]

how do i turn this into a preg_match?

I need to match if a string is all digits, if so true else false

[kows]

if(preg_match('/^\d+$/', $str)){
echo "matched!\n";
}else{
echo "no match.\n";
}