preg_match doesn't work properly!?

[chadsspameateremail]

I might have found a problem with how preg_match works though I'm not
sure.
Lets say you have a regular expression that you want to match a string
of numbers. You might write the code like this:
preg_match( '/^[0-9]+$/', $TestString );

OK everything seems fine. However, did you know if you pass the
following to preg_match: "12345\n" it will return that a match
occurred?!? Even though the newline is not a valid character in our
regular expression.

Here is the test program, *please run the program as written below*:

<?php
$TestString = "12345\n";
print preg_match( '/^[0-9]+$/', $TestString );
?>

You will find it prints 1 even though the newline character isn't a
valid part of our regular expression. What other characters I wonder
can be put in a regular expression and have the string match!? Any
ideas on this? Why is this undocumented behavior present in PHP?!?
For regular expressions to not work as expected or documented seems
like a pretty serious bug in PHP. I don't think there is a problem
with the regular expression.

Thoughts?

[Lars Eighner]

In our last episode,
<op************ ***@metallium.l an>,
the lovely and talented Rik Wasmus
broadcast on comp.lang.php:

On Tue, 27 May 2008 18:47:07 +0200, Lars Eighner <us****@larseig hner.com>
wrote:

>In our last episode,
<15*********** *************** ********@k30g20 00hse.googlegro ups.com>, the
lovely and talented ch************* ****@yahoo.com broadcast on
comp.lang.ph p:

>>I might have found a problem with how preg_match works though I'm not
sure. Lets say you have a regular expression that you want to match a
string of numbers. You might write the code like this: preg_match(
'/^[0-9]+$/', $TestString );

>>OK everything seems fine. However, did you know if you pass the
following to preg_match: "12345\n" it will return that a match
occurred?!?

Right, because it did.

>>Even though the newline is not a valid character in our regular
expression.

Doesn't matter. The whole expression matches before the newline.

>>Here is the test program, *please run the program as written below*:

>><?php
$TestString = "12345\n";
print preg_match( '/^[0-9]+$/', $TestString );
?>

>>You will find it prints 1 even though the newline character isn't a
valid part of our regular expression.

It returns 1 (a match exists) because all of the pattern is found
in $TestString. That is how perl regular expressions work.

preg_match('/dog/','catisnotadog bubba')

><SNIPPED more>

With all due respect, you're talking nonsense. You appartently missed that
the match is anchored to the start & end of string. Nothing of your story
has any relevance to the op's problem (which he already googled & solved
himself just before I answered him :) ).

$ matches the end of a line. When there is no newline, the end of a string
is presumed to be the end of a line. It was not ever anchored to "end of
string." Anyone who thinks of ^ and $ as relating to strings instead of
lines is asking for trouble.

--
Lars Eighner <http://larseighner.com/us****@larseigh ner.com
Countdown: 237 days to go.

[Rik Wasmus]

On Tue, 27 May 2008 22:15:13 +0200, Lars Eighner <us****@larseig hner.com
wrote:

In our last episode,
<op************ ***@metallium.l an>,
the lovely and talented Rik Wasmus
broadcast on comp.lang.php:

>On Tue, 27 May 2008 18:47:07 +0200, Lars Eighner
<us****@larsei ghner.com>
wrote:

>>In our last episode,
<15********** *************** *********@k30g2 000hse.googlegr oups.com>,
the
lovely and talented ch************* ****@yahoo.com broadcast on
comp.lang.php :

I might have found a problem with how preg_match works though I'm not
sure. Lets say you have a regular expression that you want to matcha
string of numbers. You might write the code like this: preg_match(
'/^[0-9]+$/', $TestString );

OK everything seems fine. However, did you know if you pass the
following to preg_match: "12345\n" it will return that a match
occurred?! ?

Right, because it did.

Even though the newline is not a valid character in our regular
expression .

Doesn't matter. The whole expression matches before the newline.

Here is the test program, *please run the program as written below*:

<?php
$TestString = "12345\n";
print preg_match( '/^[0-9]+$/', $TestString );
?>

You will find it prints 1 even though the newline character isn't a
valid part of our regular expression.

It returns 1 (a match exists) because all of the pattern is found
in $TestString. That is how perl regular expressions work.

preg_match('/dog/','catisnotadog bubba')

><SNIPPED more>

>With all due respect, you're talking nonsense. You appartently missed
that
the match is anchored to the start & end of string. Nothing of your
story
has any relevance to the op's problem (which he already googled & solved
himself just before I answered him :) ).

$ matches the end of a line. When there is no newline, the end of a
string
is presumed to be the end of a line. It was not ever anchored to "endof
string." Anyone who thinks of ^ and $ as relating to strings insteadof
lines is asking for trouble.

/m
Tricks a lot of people, for obvious reasons.
'nuff said
--
Rik Wasmus
....spamrun finished

[AnrDaemon]

Greetings, Lars Eighner.
In reply to Your message dated Wednesday, May 28, 2008, 00:11:01,

This is absurd. $ matches the end of the line. You see that is why a
"newline" is called a newline. It is after the end of the line.

$ matches the end of the line while it set to the multiline. Otherwise it
matches the end of *string* (or right before the last \n at the end of string).
Feel the difference.
--
Sincerely Yours, AnrDaemon <an*******@free mail.ru>

[Guillaume]

Lars Eighner a écrit :

Anyone who thinks of ^ and $ as relating to strings instead of
lines is asking for trouble.

Or is reading documentation carefully :p

Regards,
--
Guillaume