Reading a file.

Hey ! I have this simple code to read a file and retrieve its content but it's not working properly (it ouputs default values instead of in-file values) = /

Here's the content of the test file:

Code:

    r    
yyyyyyyyyyyyyyyy
ggggggggggggg
rrrrrrrrrrrrrrrrrrrrrr

While stepping through my code with the debugger, it seems that it jumps over the while() condition loop but I don't get why. peek() isn't supposed to return EOF since I used seekg().

Here's the function:

Code:

#include "game_load.h"

const unsigned int* Board::OpenFileContent(const char* file_path) {
	int cur_pos = 0;
	std::string line;
	std::ifstream file(file_path);
	while(file.peek() != EOF) {
		std::getline(file, line);
		if(line.size() > LineLength)
			LineLength = line.size();
		LineNb++;
	}

	Array = new unsigned int[LineLength * LineNb];

	file.seekg(0, std::ios::beg);
	while(file.peek() != EOF) {
		std::getline(file, line);
		for(int i = 0; i < line.size(); i++) {
			switch(line[ i ]) {
				case 'g':
					Array[cur_pos] = B_GREEN;
					break;
				case 'y':
					Array[cur_pos] = B_YELLOW;
					break;
				case 'r':
					Array[cur_pos] = B_RED;
					break;
				case ' ':
				default:
					Array[cur_pos] = B_EMPTY;
			}
			cur_pos++;
		}

		while(cur_pos < (cur_pos / LineLength + 1)) {
			Array[cur_pos] = B_EMPTY;
			cur_pos++;
		}
	}

	return Array;
}

And here's how I use it:

Code:

#include "game_load.h"
#include <iostream>

int main() {
	Board b;
	const unsigned int* dat = b.OpenFileContent("test.dat");
	for(int y = 0; y < b.GetLineNb(); y++) {
		for(int x = 0; x < b.GetLineLength(); x++)
			std::cout << dat[y*x + x];
		std::cout << std::endl;
	}
}

All of this is compiled using Microsoft's Visual C++ v7.1. Is there any obvious detail I didn't think of or is there any trick I am not aware of ?

Edit: Closing the file and reopening doesn't change the results. The while() condition loop is still skipped. =/
I also called fail() and it returns true which means a 'failure extracting from (the) stream'(C++ reference) occured.

Also, calling exceptions() and catch()'ing exceptions gives me a segmentation fault which is weird...

Thanks.

clear() reset flag bits

check out vector no need peek()

Kuphryn

I already tried clear() as well. No change at all. Forgot to say that.

Considering what you are doing with the data later on, you might just want to read the file character by character and make your life a bit easier, instead of peeking and grabbing whole lines.

@Citizen: I find it easier to grab whole lines as I'm used to it. Thanks, though.

It worked when I put clear() before seekg() which is logical when I think about it. However, now it outputs a lot of junk. Stepping through the debugger tells me that line contains the right string on the getline() line... but on the for() line (which is right after), it contains a lot of junk. What the hell does that mean ?

I don't understand what all this peek should be good for. Just use the normal way to read from a stream line by line

Code:

	while( std::getline(file, line) ) {
		if(line.size() > LineLength)
			LineLength = line.size();
		LineNb++;
	}

Kurt

I didn't know about that trick, thanks.

Apparently, what's messed up is how I show the content of the array. When I displayed it on a single line it displayed all the correct values. I'll have to check back my algorithm = /

Thanks all !