A Screen Replacement

Author: (Norbert) Suedland, Aalen, Germany

In the face of a yet not completely finished list of all Unicode charaters for the screen output, there is a welcome replacement: the protocol file.

In C, the input via a keyboard or the output onto the screen are carried out as read and write operations of corresponding files. Therefore, here can alternatively be written also into a file, where today's Unicode font has been clearly expanded in comparison with Windows 95.

Already under Windows XP, there are at least three different Unicode codings:

• The usual Unicode from the code page 1252 begins with the character 0xFEFF.
• The coding Big Endian swaps both bytes of all Unicode characters and therefore begins with 0xFFFE.
• The coding UTF-8 from the code page 65001 begins with the three 8 bit characters  and remains unchanged for English texts and programmes in comparison with an 8 bit coding. Therefore many programmes with English source code access to this format, while the very Unicode has been avoided for a long time concerning programming.

Therefore, the first programming example now is deviating from Kernighan and Ritchie [1988KR] a programme, which does not generate screen output, but file output only. Here, a programme is suitable, which lists the predefined switches for the compiler.

Programme protocols in English are called log file, analogously to the log book of shipping, and end with .log. Such protocols are also possible, if the user of a programme carries out many things by use of the mouse. The protocol file in comparison with keyboard and screen is not opened automatically at the begin of a programme, but first must be opened and then be written. Windows is organized in such a way, that keyboard and screen have been opened for C programmes in text mode and therefore depending on the Windows version cannot process Unicode characters, if the programme avoids Windows functions:

• Therefore, the protocol file must also be opened in the binary mode, thus Unicode characters can be printed there.
• The protocol file shall overwrite an already existing or first generate the same newly.
• The programme shall now and then be able to read its own protocol file.
• These three demands result in the file mode w+b for opening the protocol file, which can be translated into other languages by the macro binary_writing_and_reading.