preg_replace limit?

[DrDoc]

Is there a limit to how much data preg_replace can handle?

Say that I have a 20k string, can I just do a preg_replace to replace all newlines with <br>?

[aaronc]

Wow, a 20k string is big. I don't know if php will even support a 20k variable.
I'm assuming you're getting it from a file.
It might make more sense to read in the file a line at a time and do each line and output it back to another file.

[andreasfriedrich]

The longer the string the longer will the re engine need to do the matching. If you use backreferences the time will increase exponentially. That being said 20K is not a problem at all.

I just run a preg_replace [php.net] on a 213K file. Processing was still very fast. If you get really large strings from a file it might indeed be better to run the re on chunks of the file.

nl2br [php.net] might be helpful as well.

Andreas

[DrDoc]

That's what I thought as well... that there really isn't a limit. The other thing is that I'm not just doing the \n=>br replace. I need to be able to match and/or replace text strings spread out over the whole file. Line-by-line matching isn't an option.

And yes, it's input from a file... Size anywhere between a few Kb up to almost 50...

It's working again now .. Don't know why it didn't for a while. :)

[nosanity]

Just to make people scratch their heads, I just tried a preg_replace on a 50 MB file. Well, it worked, but it made my patheticly slow dev server crawl, but it has tons of ram...

noSanity