U++

#include <Core/Core.h>

using namespace Upp;

String GetLineEndings(const String& data, const String& default_eol = "\r\n")

{

        int q = data.ReverseFind("\n");

        if(q >= 0) {

                if(data.Mid(q - 1, 1) == "\r")

                        return "\r\n";

                else

                        return "\n";

        }

#if 0

        else if(data.ReverseFind("\r") >= 0)

                return "\r";

#endif

        return default_eol;

}

CONSOLE_APP_MAIN

{

        const String data_crlf = "text\r\n",

                data_lf = "text\n",

                data_default = "text",

                data_mid_lf = "text\ntext";

#define TEST(x) Cout() << #x << ":\n" << (GetLineEndings(x) == "\r\n" ? "CRLF" : "LF") << '\n';

        TEST(data_crlf)

        TEST(data_lf)

        TEST(data_default)

        TEST(data_mid_lf)

        const String line_endings = GetLineEndings(data_default, Null);

        Cout() << "Check for empty line endings:\n"

                << (IsNull(line_endings) ? "Null" : line_endings == "\r\n" ? "CRLF" : "LF") << '\n';

}