find . -type f -print0 | xargs -0 perl -pi 's/\r/\n/g;'

Note the -print0 flag for xargs and the -0 flag for xargs. What does this do? It delimits the filenames with zero rather than space or newline. This is extremely useful for files that have spaces, newlines and what-have-you in their names.

To restrict the search to just the current directory, use the flag -maxdepth 1 argument for find:

find . -type f -maxdepth 1 -print0 | xargs -0 perl -pi 's/\r/\n/g;'

[ Reply to This | # ]

First off a big warning: BACKUP your original mailboxes before you do this.

The correct command is

find . -type f -print0 | xargs -0 perl -pi -e's/\n/\r/g'

I used this command to "fix" my Mozilla mailboxes (folders). For reasons I can't explain about 20% of the messages were affected by the newline / carriage return problem. I thought it had to do with the date, maybe the origin... I have switched from Netscape to Mozilla to Thunderbird in the past seven years, and all Mail clients have been backward compatible with the mbox format.

When I ran this command, the "bad" messages were "fixed", but the other 80% of the messages lost their "From" fields. So I had to import twice and then merge the results. This was a nightmare, if you want my opinion.

Why did I do it? Because the Search function in Mozilla / Thunderbird under Panther performs horribly (slow). In retrospect I would say Apple's Mail app should have a more robust and/or lenient Import function. The newline/carriage return problem is well documented, I don't know why they didn't catch this before. Hopefully the Tiger will fix this.