drysler,
So you are asking about what PHP6 calls "script_encoding". PHP5 does not
have this concept.
PHP5 does not know the character set that your script is encoded in. The
script can be encoded in any character set that is "ASCII compatible".
ASCII compatible encodings have the property that any byte value which has
a meaning as an ASCII character has the same meaning in the
character set. iso-8859-1 or utf-8 both have this property whereas utf-16
for example does not. There are rules about
what characters can be used in identifiers, (see
http://uk.php.net/manual/en/language.functions.php#functions.user-defined)
but you'll see that
these are described in terms of byte values. Thus when you define an
identifier or string literal in a script it is simply treated as a series
of byte
values by PHP without any understanding of the meaning of those byte
values other than if they happen to represent ASCII characters.
Rob.
drysler <drysler@gmx.de> wrote on 27/09/2007 20:32:09:
> > On 9/27/07, drysler <drysler@gmx.de> wrote:
> >> Hello,
> >>
> >> i am practising with charsets at the moment and so i thought:
> >>
> >> -> How does PHP know the charset i use in my source-code?
> >> -> Are php-sources limited to specific charsets?
> >> -> In which areas you have to be aware of the source-code-charset?
> >>
> >>
> >> Perhaps somebody here on the list can tell something about these
issues?
> >> Thanks!
> >>
> > Unless I'm mistaken, PHP expects the source files to be in the
> > internal charset, which is ISO-8859-1. If you use the mbstring
> > extension, you can use different internal encodings. See:
> > http://www.php.net/mbstring
> >
> > Another good read on charset vs. PHP is:
> > http://www.phpwact.org/php/i18n/charsets?s=utf
> >
> > --
> > troels
>
>
> I think, the problem may be divided into 2 areas:
>
> 1) handling charsets of data (e.g. regex or string functions)
> ------------------------------------------------------------------------
> No unsolvable problem. You have to know (and/or validate) the charset of
> the data you process, no matter if typed in in the source code or loaded
> from other data sources. There are "tools and workarounds" available, to
> do the things right.
>
> 2) paying attention to the charset of the source code
> ------------------------------------------------------------------------
> This is the main issue, i wanted to address with my posting.
> I asked myself, if there can be characters i use as source code, which
> php perhaps can not recognize because of the charset i used in the
> source-code-document.
> Or perhaps in php are only characters "allowed", which are represented
> all the same in all supported charsets, so there might be a list of
> charsets, you can safely use when scripting php.
>
> I mean, is there a difference (bytes?) writing the following in
> iso-8859-1 or utf-8?
>
> public function foo($bar = true) {
> return self::SOME_CONSTANT;
> }
>
> And if there is a difference, how php knows what i typed?
>
> So many questions .... :)
>
>
> --
> Greetings,
> drysler
>
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