Re: Coding hints?

Gavster writes: > Hi Guys, > > Sorry to post with something trivial, but I can't seem to find anything on > this: > > I'm modifying some code to recognize a certain filename scheme, but I've > run across something I've never seen before. > > Here's the code: > > $arr = file('sb' .(int)$sb. '.src'); > > The filename it's looking for is in the form sbN.src (where N = an integer). > > The $sb variable is an integer passed via the url. > > What I don't get is the (int)$sb part - what is the (int) doing there? Is > this some sort of funky regex? Or is it casting the $sb string into an > int? I must admit, I'm at a loss . . . The second one--any time you see parentheses not relating to a function's argument list, containing a sole word which is the name of a data type, it's a cast. More information on casting and PHP data types is available here: http://www.php.net/manual/language.types.type-juggling.php In the above, it would appear that the coder was trying to ensure that the $sb variable contained only integer data. For instance, if $sb was equal to '23foo', the (int) $sb would result in only the '23' part being used. Check out PHP's string conversion rules for more information here: http://www.php.net/manual/language.types.string.php#language.types.string.conversion > What I'm ultimately trying to do is to get the code to recognize files > where $sb is not only a number, but is also a number with a single char > appended to it such as [a-z]. Can't this be done with a straightforward regex? > > > Any pointers would be greatly appreciated . . . =0) Sure--but it'll make the whole thing slightly longer: if (preg_match('/^[0-9]+[a-z]?$/i', $sb)) { echo "$sb matched<br>\n"; } else { echo "$sb did not match<br>\n"; } Step-by-step explanation of the regex: / At the beginning and end: needed by preg_match(); anything between the // marks is part of the regex; anything following it is a modifier which changes some part of the regex's interpretation. ^ Must match starting from the beginning of the string. [0-9] Match digits from 0-9... + ...one or more times (i.e. must be at least one digit). [a-z] Next, match chars from a-z... ? ...zero or one times (i.e. there may be at most one char). $ Must match right up to the end of the string. / See above; this is the closing / delimiter. i Make search case-insensitive. This is a bit simplified, but there is more information in the manual: http://www.php.net/manual/ref.pcre.php Hope this helps, Torben -- +----------------------------------------------------------------+ |Torben Wilson <torben@php.net> Netmill iTech| |http://www.coastnet.com/~torben http://www.netmill.fi| |Ph: 1 250 383-9735 torben@netmill.fi| +----------------------------------------------------------------+