note krusty An efficient alternative to: <CODE> while (<DATA>) { $_ .= <DATA>; s/^0\s*(.*)\n\s+(.*\n)/$1 $2/s; print; } </CODE> is not to even loop at all. <CODE> { local $/ = undef; $_ = <DATA>; s/^0\s*(.*)\n\s+(.*\n)/$1 $2/s; print; } </CODE> caveat is that it eats up memory if you have an extremely large file. Cheers, Kristina Update: See BrowserUK's post immediately below. /s would allow the "." to match the newline which I don't want to happen here, but /m will treat the single string as multiple lines and /g will let me match more than once before quitting. 205602 205608