I am writing code that runs in Windows and outputs a text file that later becomes the input to a program in Linux. This program behaves incorrectly when given files that have newlines that are CR+LF rather than just LF.
I know that I can use tools like dos2unix, but I'd like to skip the extra step. Is it possible to get a C++ program in Windows to use the Linux newline instead of the Windows one?
Are you using printf to write to the file? Have you explored the various combinations of
\n - Newline
\r - Carriage Return
\f - Form Feed
\v - Newline (only some platforms, different from \n)
If those don't work, look into \XXX (where XXX is 3 octal digits, specifying exactly the character code you want)
If you're using cout, try using:
cout << "My Text" << (byte)0x0A;
Yes, you have to open the file in "binary" mode to stop the newline translation.
How you do it depends on how you are opening the file.
Using fopen:
FILE* outfile = fopen( "filename", "wb" );
Using ofstream:
std::ofstream outfile( "filename", std::ios_base::binary | std::ios_base::out );
OK, so this is probably not what you want to hear, but here's my $0.02 based on my experience with this:
If you need to pass data between different platforms, in the long run you're probably better off using a format that doesn't care what line breaks look like. If it's text files, users will sometimes mess with them. If by messing the line endings up doing so they cause your application to fail, this is going to be a support intensive application.
Been there, done that, switched to XML. Made the support guys a lot happier.