Deleting multiple blank lines from a file

bink

Hello all,

I have a file opened (as an array) which I will later implode into a single string. What I need to do is replace all multiple blank lines with a single blank line...ie: replace a double or triple space with a single line return. Please let me know how I can acheive this goal.

Thanks in advance,
Kevin

archangel_617b

Handling strings in any way shape or form? Crack open the regex function ([man]ereg/man and [man]ereg_replace/man). You can abuse strings in way way imagineable. For example, take you imploded string, $str, and convert multiple newlines to a single newline:

$str = implode($stuff);
$str = ereg_replace("(\n|\n\r){2,}", "\\1", $str);

Having not used this myself, I do not know if this works. Please test it and tell me if I boloxed it. Hopefully you are at least looking in the right direction for you solution now 😛

Uh, the second argument to ereg_replace() should have two whacks (\ twice) before the '1'... PHP won't display it though.

bink

That worked like a charm!

Guess its time for me to learn reg expressions now...

Thanks again,
Kevin

Weedpacket

You could also work on the file directly; if for each line $i, $file[$i]=="\n" or "\r\n" (depending on system), then unset($file[$i]).

What's left would be an array of nonempty lines.

If you are going to learn regular expressions (and that's a good idea in itself), the PCRE syntax of preg_replace and the like is more powerful than the POSIX-style used by the ereg functions (not in theoretical terms, but certainly in practical ones.)