(PHP 5)
iconv_strpos — Finds position of first occurrence of a needle within a haystack
$haystack
   , string $needle
   [, int $offset = 0
   [, string $charset = ini_get("iconv.internal_encoding")
  ]] )
   Finds position of first occurrence of a needle
   within a haystack.
  
   In contrast to strpos(), the return value of
   iconv_strpos() is the number of characters that
   appear before the needle, rather than the offset in bytes to the
   position where the needle has been found. The characters are counted
   on the basis of the specified character set charset.
  
haystackThe entire string.
needleThe searched substring.
offset
       The optional offset parameter specifies
       the position from which the search should be performed.
      
charset
       If charset parameter is omitted,
       string are assumed to be encoded in
       iconv.internal_encoding.
      
   If haystack or needle is
   not a string, it is converted to a string and applied as the ordinal
   value of a character.
  
   Returns the numeric position of the first occurrence of
   needle in haystack.
  
   If needle is not found,
   iconv_strpos() will return FALSE.
  
Questa funzione può
restituire il Booleano FALSE, ma può anche restituire un valore non-Booleano valutato
come FALSE. Fare riferimento alla sezione Booleans per maggiori 
informazioni. Usare l'operatore ===
 per controllare il valore restituito da questa 
funzione.