[RESOLVED] Pattern sequence problem in preg_replace

void_function

I have this source text:

[start]
  someting
[end]

blahblah

[start]
  something else
[end]

Now, if I replace [start] and [end] tags with appropriate HTML tags using this:

$str= preg_replace ('/\[start\](.*)\[end\]/i', '<htmltag>\1</htmltag>', $str);

the first [start] and LAST [end] are matched! How do I force it to consider "adjecent" [start] and [end] tags as proper pattern instead?

Thanks!

Installer

Try this:

$str = str_replace(array('[start]', '[end]'), array('<htmltag>', '</htmltag>'), $str);

void_function

Yeah, but I need preg_replace for other reasons, especially for callback, I just gave simple example here.

Installer

I see.

rkolbe

$str= preg_replace ('/[start](.*)[end]/i', '<htmltag>\1</htmltag>', $str);

What your regex is saying is this:

Find [ followed by s, t, a, r, t, ] followled by any character (.) of 0 to infi. Followed by [ followed by e, n, d, ].

I think what is happening is that its working correctly! 😉

Try using the ^ and $ before and after [start] and [end] to signify that each of these items are on their own line all alone. Also, maybe you need to tell your regex that (.*) is really on a new line since right now its looking for [start] sdjfhsdkfjhsfj [end].

What you have written for a regex is working exactly how it should be. The issue probably is with (.*) as well since it is saying "hey match one or more to infinity characters between [start] and [end]. Which allows [start][start][end][end] to be valid here.... maybe you need to negate [^[start]] and [^[end]] so that your final code would be something like:

$str= preg_replace ('/\[start\](.*)[^\[start\]] [^\[end]\]\[end\]/i', '<htmltag>\1</htmltag>', $str);

But I am no regex expert... for real! Plus this is not tested code and I am no pro with PHP regex stuff.

rkolbe

Ok so I tested your code...what format, spacing, returns, etc is this in:

[start]
someting
[end]

blahblah

[start]
something else
[end]

Because if you have it all on one line (no \n or \r) then your code is working fine. The problem is the \n, php doesn't know how to tell it apart for the new lines...Im looking into some stuff here... heh

NogDog

Use the ungreedy modifier "U":

$result = preg_replace('/pattern/[color=red][b]U[/b][/color]', 'replacement', $string);

altexis

This will work:

$str= preg_replace ('/\[start\]([^[]*)\[end\]/i', '<htmltag>\1</htmltag>', $str);

but it assumes that there are no square brackets in your text.

void_function

There is no rule if the tags will be on new line or everything in one row, I must solve for all situations, so I include \n in the dot metacharacter (/s modifier).

That was my temporary solution until I hit situation with more [] tags inside.

Anyways, NogDog's advice helped! The greediness modifier solved the case, and it makes sense why.

Thanks all! 😉