Unix c++: getline and line.empty not working

Question

Happy New Year, everyone!

I have a text file that looks like this:

A|AAAAA|1|2
R|RAAAA
R|RAAAA

A|BBBBB|1|2
R|RBBBB
R|RBBBB

A|CCCCC|1|2 
R|RCCCC

The following code searches for the relevant text in the file based on the key and returns all the lines that belong to the key:

while( std::getline( ifs, line ) && line.find(search_string) != 0 );

if( line.find(search_string) != 0 )
{
    navData = "N/A" ;
}

else{

    navData = line + '\n' ; // result initially contains the first line

    // now keep reading line by line till we get an empty line or eof
    while( std::getline( ifs, line ) && !line.empty() )
    {
        navData += line + '\n';
    }
}

ifs.close();
return navData;

In Windows I get what I need:

A|BBBBB|1|2
R|RBBBB
R|RBBBB

In Mac, however, code "&& !line.empty()" seems to get ignored, since I get the following:

A|BBBBB|1|2
R|RBBBB
R|RBBBB

A|CCCCC|1|2
R|RCCCC

Does anyone know why?

Cheers, everyone!

Answer 1

Windows and Mac have different opinions about how an empty line looks like. On Windows, lines are teminated by "\r\n". On Mac, lines are terminated by "\n" and the preceding "\r" leads to the line not being empty.