Create new file po in cakephp merge with old file po

I crea开发者_运维百科ted a po file by cake command. However, after editing some template file, I have to insert more string for translating. How could I created new po file by cake command with old translated string in old po file? Thanks and best regard.

Hopefully you are using source control, in which case it is easy... Svn or git will handle this for you.

If you are not, you're in for a long night of manual merging and hair pulling.