FileIO homework

[HavocVulture]

I'm getting erratic behavior with the print function shown in the tutorial. Sometimes it overwrites text written to the console previously.

For example:

Code: Select all

struct nvPair {
	char name[10];
	char value[5];
};

nvPair pairs[100];

void printChart( nvPair pairs[], const int nameLength, const int valueLength, int nvIndex ) {
	fio::print( "	Beautiful Chart Bitches!\n" );
	fio::print( "	------------------------\n\n" );

	for ( int j = 0; j < nvIndex; j++ ) {
		fio::print( pairs[j].name );
		fio::print( "|" );

		for ( int i = 0; i < fio::str2int( pairs[i].value ); i++ ) {
			fio::print( "=" );
		}
		fio::print( "\n" );
	}
}

If I add a name value pair, say, "steve" and "3", what's output is:

fio::print( pairs[j].name ); outputs "steve 3"

Not sure where the 3 is coming from.

fio::print( "|" ); overwrites the "s" in "steve"

fio::print( "=" ); overwrites more letters in "steve" for each "=".

Is this another VC++ compiler error or am I using it wrong?

[MrGodin]

not sure what the fio::print function is doing, possible not setting a end line call or '\n' at the end of each print ?

[chili]

gib the full file an we can take a quick look at er.

[HavocVulture]

Here it is on github: https://github.com/CorpseLiquor/FileIO/ ... O/Main.cpp

[albinopapa]

while (c != 13 && (buf < pEnd + 1))

13? A new line is represented as \n or 10, 13 is carriage return \r. This is why your cursor goes back to the beginning of the current line instead of next line.

Ok, so it does need to be 13 to end the input, but I don't think it should be added to the string.

Code: Select all

	void read(char* buf, int maxSize) {
		const char* const pEnd = buf + maxSize;
		char c = 0;

		while (c != 13 && (buf < pEnd)) {
			c = _getch();
			if (c != 0) {
				_putch(c);
				*buf = c;
				buf++;
			}
		}

		*buf = 0;
	}

Probably should be echoing the characters when you read them. The console prints out the characters as they are typed, so no need. Also, when you press enter, you echo the \r and the cursor gets returned to the beginning of current line.

Another thing is if you mistype and press backspace, it's counted and added to the buffer which is probably not what you want. Perhaps skipping anything that isn't a alpha character in names and numeric character in values ( like tab ( \t ), backspace ( \b ), etc... ).

[HavocVulture]

Thanks albinopapa. I added a function to limit non alphanumeric characters and fixed readw so the string is properly null terminated. Seems to be functioning a lot better now. You can see the changes on github.

[albinopapa]

You're welcome.

It's weird really. In the 6 years I've been doing this, I haven't run into this issue dealing with the console, only when displaying text in a custom GUI. I'm guessing it's because I probably didn't follow along this time around. Using the C library fprint and scanf or the C++ library std::cout and std::cin it deals with tabs and backspaces and only presents you with everything up until the enter key. Using _putch and _getch on the other hand, you must handle every key press.