[PHP] php seems to be inconsistent in its handling of backslashes ... maybe?
-- or maybe it's just the PCRE extension
-- or quite likely I have got something wrong
Hello members,
I'm hoping you could enlighten me.
Using error_reporting = E_ALL | E_STRICT, I tested the
following statements:
warning
preg_match('#\\\#','any-string');
preg_match('##','any-string');
preg_match('#\#','any-string'); => warning
preg_match('#\\#','any-string'); => warning
preg_match('#\\\#','any-string');
?>
This seemed strange:
warnings with 2 and 6 backlashes
no warnings with 3, 7
warning with 5 but not with 3 and 7.
The warning related of course to no matching delimeter '#'
being found.
So I wrote a little test script (preg.php) to test up to 10
backslashes:
Here is the output:
$ php preg.php
-
Number of '\' is 1
Pattern is: #\#
error
-
Number of '\' is 2
Pattern is: #\\#
ok
-
Number of '\' is 3
Pattern is: #\\\#
error
-
Number of '\' is 4
Pattern is: ##
ok
-
Number of '\' is 5
Pattern is: #\#
error
-
Number of '\' is 6
Pattern is: #\\#
ok
-
Number of '\' is 7
Pattern is: #\\\#
error
-
Number of '\' is 8
Pattern is: ##
ok
-
Number of '\' is 9
Pattern is: #\#
error
-
Number of '\' is 10
Pattern is: #\\#
ok
End of output.
This agrees with my understanding of backslash escaping (I
hope that's right) but now I can't understand why I got the
results earlier (shown in my first script).
Many thanks.
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Re: [PHP] php seems to be inconsistent in its handling of backslashes ... maybe?
Richard Lynch wrote:
warning
This seemed strange:
warnings with 2 and 6 backlashes
For 2 backslashes, PHP "ate" the 2 backslashes, and handed PCRE #\#,
and PCRE does not like that at all.
Yet preg_match('#\\#','any-string'); does *not* throw a
warning when I run the 2nd script - the one where I call it
in the loop.
no warnings with 3, 7
warning with 5 but not with 3 and 7.
PHP and PCRE are doing their damndest to make sense of the garbage you
typed, but if you type garbage, you get garbage.
http://us.php.net/manual/en/language.types.string.php
But PHP doesn't appear to be consistent. In the 2nd script,
I *do* get warnings with 3 and 7 slashes.
PHP can't be inconsistent. So there must be some semantic
difference in my 2 scripts which unfortunately is eluding me.
Cheers
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Re: [PHP] php seems to be inconsistent in its handling of backslashes ... maybe?
Al wrote: The proper way to handle special control PCRE characters like "\" is to use the hex [e.g., \x5C] value. Then you won't have a problem. The engine knows you want the the object treated as a character and an a control. That works nicely, thank you. -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
[PHP] Best practices to ensure compatibility with PHP 6
Hi I'm would like to avoid PHP usages that are deprecated with regard to PHP 6. I would also like to code according to what is regarded as best practice. Are there any web resources that I can read to keep up to date? For instance: 1) safe_mode is deprecated. (The PHP manual gives me the answer) 2) Are named accessor/mutator methods recommended over the __get() and __set() magic methods? (A best practice question). Thanks -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] Best practices to ensure compatibility with PHP 6
Davi wrote: Em Domingo 22 Abril 2007 18:54, [EMAIL PROTECTED] escreveu: ... Have a look at PHP metting [1] and PHP-wiki [2]... =] [1] - http://www.php.net/~derick/meeting-notes.html [2] - http://oss.backendmedia.com/PhP60 Thank you for the links - it will get me started. -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
