Using grep on Mac-style text files When I run grep on a text file, I get nonsense results. It seems as if the whole file is printed out but on one line overwriting itself.   I read that on the Mac, text files use \r instead of the normal \n as a line ending.  That would explain it, but how to make grep treat \r as if it were \n?

I'm using Snow Leopard OS X, and am quite new to using Apple anything, but a long-time Linux programmer.
You can't change grep's behavior, but you can change the file it sees:

tr '\r' '\n' &lt;file | grep foo


Also, \r line endings are legacy these days; OS X officially uses \n, although there are still things that haven't been updated.  In particular, AppleScript still hasn't quite caught up, which also shows in its using pre-OS X file paths by default and requiring POSIX file to indicate OS X native paths; also, many Carbon applications still use \r, Carbon being a transition framework from Mac OS 9 to OS X.