(PHP 3 >= 3.0.3, PHP 4, PHP 5)
strcspn -- 
     Find length of initial segment not matching mask
    
Description
int 
strcspn ( string str1, string str2 [, int start [, int length]] )
     Returns the length of the initial segment of
     str1 which does not
     contain any of the characters in str2.
    
     As of PHP 4.3.0, strcspn() accepts two optional 
     integer parameters that can be used to define the 
     start position and the 
     length of the string to examine.
    
Note: This function is
binary-safe.
     See also strspn().