public static BIN Parse(FileStream reader)
{
reader.Seek(0, SeekOrigin.Begin);
BIN Output = new BIN()
{
Instructions = new byte[reader.Length]
};
reader.Read(Output.Instructions, 0, (int)reader.Length);
return(Output);
}
public ParseResult Parse(ParseMode mode, out byte[] Instructions)
{
byte[] MagicBytes = new byte[4];
// Open the file as read only.
using (FileStream Reader = TargetFile.Open(FileMode.Open))
{
if (mode == ParseMode.AUTO)
{
// There must be no less than 4 bytes in the file in order to determine its magic bytes. This is not necessarily true for
// every file type. If there are only 3 bytes in the read file, the user probably chose the wrong file anyway.
// Reader.Read() returns the number of bytes read.
if (Reader.Read(MagicBytes, 0, 4) != 4)
{
Logger.Log(LogCode.IO_INVALIDFILE, "File must be no less than 4 bytes in length");
Instructions = null;
return(ParseResult.INVALID);
}
// Order the bytes in big endian(because was read from a file) to form the signature of magic bytes.
// Most magic byte signatures are 4 bytes, especially for the purposes of this program.
int Signature = MagicBytes[3] + (MagicBytes[2] << 8) + (MagicBytes[1] << 16) + (MagicBytes[0] << 24);
// Check if the file type can be inferred from the magic byte signature from the signatures registered in the SignatureTable.
MagicDelegate ResultDel;
if (SignatureTable.TryGetValue(Signature, out ResultDel))
{
IMyExecutable Result = ResultDel(Reader);
// If $Result is null after parsing, there was an error in doing so.
if (Result == null)
{
Instructions = null;
return(ParseResult.INVALID);
}
else
{
Instructions = ResultDel(Reader).Instructions;
return(ParseResult.SUCCESS);
}
}
else
{
// If the file type cannot be inferred,
Instructions = null;
return(ParseResult.NOT_INFERRED);
}
}
// Other parse modes for forcing files to be interpreted as a particular format.
else if (mode == ParseMode.BIN)
{
Instructions = BIN.Parse(Reader).Instructions;
return(ParseResult.SUCCESS);
}
else if (mode == ParseMode.TXT)
{
TXT Result = TXT.Parse(Reader);
// If $Result is null after parsing, there was an error in doing so.
if (Result == null)
{
Instructions = null;
return(ParseResult.INVALID);
}
else
{
Instructions = Result.Instructions;
return(ParseResult.SUCCESS);
}
}
}
// This should never be reached.
throw new System.Exception();
}
