fgetc returning -1?

[SuperStinger]

Hey all

I have been working on a tile based game (birds eye view type of thing) and im reading a map from a text file (or multiple).

Everything seems fine until I use fgetc on the char variable 'tempChar' to grab a char from the file, however, i printf to stdout and tempChar, for every fgetc i do, returns -1. Ive done tests and its not an error as the program would simply crash, it is reading the file incorrectly and i don't know why...

This is what the text file (one of the text files im trying to read from) looks like

EGGFCCCDEC
ABFGDDCGED
EDAFDEACGF
ADFECBCDEB
DBFADFAFGB
DBGGDEFAAB
AGEDABCBFB
DFBBCEGCCG
DCCGCBBCGD
GGEGGBBGDD

heres the function...

void defineMap::loadChunk(int x, int y, char* filePath)
{
	//this will determine which chunk to load into!
	int whichChunk;

	//Check the various chunks in the map to see whether they are in use
	for (int i = 0; i < (maxLoad * maxLoad); i++)
	{
		if (defineMap::map[i].inuse != 1)
		{
			whichChunk = i;
			break;
		}
	}

	//Set the chunks x and y so we know where to put it!
	defineMap::map[whichChunk].x = x;
	defineMap::map[whichChunk].y = y;

	//for the while loop!!
	int i = 0;
	int j = 0;

	char tempChar;

	//Create file stream and read the file
	FILE* mapFile;
	mapFile = fopen(filePath, "r");

	//Actually read the file
	while (!feof(mapFile))
	{
		tempChar = fgetc(mapFile);
		printf("CHAR: %c %i ---- %i %i\n", tempChar, tempChar, i, j);

		if (tempChar == '\n')
		{
			j++;
			i = 0;
		}
		else
		{
			defineMap::map[whichChunk].map[i][j] = tempChar;
			i++;
		}
	}
}

NOTE: this function is in the class 'defineMap', i don't think that would have anything to do with it...would it?



Here is some of stdout (from printf around line 34)...

PATH: map1/0-0.txt
CHAR: ÿ -1 ---- 0 0
PATH: map1/0-1.txt
CHAR: ÿ -1 ---- 0 0
PATH: map1/0-2.txt
CHAR: ÿ -1 ---- 0 0
PATH: map1/0-3.txt

[kbw]

What is errno, and what does strerror(errno) say?

[SuperStinger]

hmm, the program does not crash at this point, is errno the return number when the program crashes?

EDIT: Ok i tried at errno and strerror, this is the results

errno returns: 17
strerror(errno) returns: 11075112

[kbw]

Can you show the definition of defineMap

[coder777]

errno == 17 means: "file exists" which makes not too much sense in case of read. But it may not opened for other reasons. Check if mapFile != NULL

you should rather use ferror():

http://www.cplusplus.com/reference/clibrary/cstdio/ferror/

[vlad from moscow]

You should check whether mapFile is equal to NULL after opening it

mapFile = fopen(filePath, "r");
if ( !mapFile ) { /* some action */ }

[SuperStinger]

Hey all thanks for your help, ill try the NULL thingo in a sec

this is for kbw:

//class for map stuff!
class defineMap
{
	public:
	void loadChunk(int x, int y, char* filePath);
	void unLoadChunk(int x, int y);
	void loadTextures(char* fileName);
	void drawMap(SDL_Surface* screen);
	//void defineMap::loadMap(SDL_Surface* screen);
	private:
		chunk map[maxLoad * maxLoad];
		vector<texture> textures;
};

just the code for the defineMap class

[kbw]

Thanks, and what is the definition of map in:

chunk map[maxLoad * maxLoad];

[SuperStinger]

Sorry for late reply

kbw:
maxLoad is just a global variable defined that currently = 10.

to many other people:
I tried getting a return on 'mapFile' or the stream and its not NULL
I dont understand why its returning -1, Its not an error or anything because if it was an invalid file path, it would crash (at that particular point).

EDIT: I also tried ferror() and it returns 0...funny that...

[SuperStinger]

I think i may have found the problem, in one of my previous functions, i create the files, but i think i forgot to close the stream, so all the files were still open when i tried to access them with a new stream (sorry for double post!)