views:

100

answers:

2

I'm writing a command-line tool for Mac OS X that processes a bunch of files. I would like to show the user the current file being processed, but do not want a bazillion files polluting the terminal window.

Instead I would like to use a single line to output the file path, then reuse that line for the next file. Is there a character (or some other code) to output to std::cout to accomplish this?

Also, if I wanted to re-target this tool for Windows, would the solution be the same for both platforms?

+3  A: 

"\r" should work for both windows and Mac OS X.

Something like:

std::cout << "will not see this\rwill see this" << std::flush;
std::cout << std::endl; // all done
Logan Capaldo
... and Linux, and pretty much everything else. I think the only platform that one can still theoretically run into that won't handle this correctly is pre-X versions of Mac OS.
Pavel Minaev
+1  A: 

I don't have access to a mac, but from a pure console standpoint, this is going to be largely dependent on how it treats the carriage return and line-feed characters. If you can literally send one or the other to the console, you want to send just a carriage return.

I'm pretty sure Mac treats both carriage returns and line-feeds differently than *nix & windows.

If you're looking for in-place updates (e.g. overwrite the current line), I'd recommend looking at the curses lib. This should provide a platform independent means of doing what you're looking for. (because, even using standard C++, there is no platform independent means of what you're asking for).

Nathan Ernst
Mac _used_ to treat CR differently from Win/Unix back in the day when it was not Unix itself. But now it is, and that problem is gone.
Pavel Minaev