strcspn Find length of initial segment not matching mask intstrcspn stringstr1 stringstr2 intstart intlength Returns the length of the initial segment of str1 which does not contain any of the characters in str2. As of PHP 4.0B1 this function is binary safe. Additionally it accepts two optional integer parameters that can be used to define the starting position and the length of the string to examine. See also strspn.