Hello, I am fairly new to Perl, and I have been trying to use some regular expressions in a Perl one liner to replace \r\n (or \n on Unix) with a single space, thereby joining lines. It is however a bit more involved than that because this joining should only happen under certain conditions. Here is the kind of text files that I am dealing with:

line
  de
    Bitte lesen Sie die Gebrauchsanweisung gut durch und bewahren Sie
    diese auf.
  en
    Please read these instructions carefully and keep for future
    reference.
  fr
    Lire et conserver ces instructions pour toute utilisation future
    du produit.
line
  de
    19 Zubehoerteile.
  en
    19 Accessories.
  fr
    19 Accessoires
line
  de
    10 Aktivitaeten.
  en
    10 Activities.
  fr
    10 Activite's.
[download]

I have a whole list of text files with text in German, French and English. All lines containing meaningful text are preceded by 4 spaces. However, I would like to have only a single line of text under each language for those language lines that space multiple lines (a line being 76 characters long maximum at present). In other words, the above would become:

line
  de
    Bitte lesen Sie die Gebrauchsanweisung gut durch und bewahren Sie 
+diese auf.
  en
    Please read these instructions carefully and keep for future refer
+ence.
  fr
    Lire et conserver ces instructions pour toute utilisation future d
+u produit.
line
  de
    19 Zubehoerteile.
  en
    19 Accessories.
  fr
    19 Accessoires
line
  de
    10 Aktivitaeten.
  en
    10 Activities.
  fr
    10 Activite's.
[download]

The languages text that already span only 1 line are left untouched, whereas the other lines, where the language text spans more than 1 lines, are joined. I have tried several regular expressions, all of them as Perl one liners as I thought it would be an extra challenge to do it all one 1 line, such as

perl -i.bak -pe 's/^\s\s\s\s(.*)$\n\s\s\s\s/$1/g' myfile.txt
perl -i.bak -pe 's/\n\s\s\s\s/ /gm' myfile.txt
[download]

However, none of my regular expressions works. It looks as if anything specified after the \n is ignored. Any idea? Any help would be immensely appreciated? Thank you very much

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