Thread: Reading char matrix from file

Why does this program not work as expected? (Read the file test.txt and output it to stdout as written in the file)

Code:

#include <stdio.h>
#include <stdlib.h>
#include <assert.h>

#define  GRIDWIDTH   10
#define  GRIDHEIGHT  10

FILE *fin;

//#define POINTERS

#ifdef POINTERS
char *grid[GRIDHEIGHT];
#else
char grid[GRIDHEIGHT][GRIDWIDTH];
#endif

int main(int numargs, char **firstarg) {
	fin  = fopen("test.txt",  "r");
	int i, j;
	int fx, fy, fd = 0;
	int cx, cy, cd = 0;
	for (i = 0; i < GRIDHEIGHT; ++i) {
        #ifdef POINTERS
        grid[i] = malloc(GRIDWIDTH);
        #endif
        #if 1
        for (j = 0; j < GRIDWIDTH; ++j) {
            grid[i][j] = getc(fin);
        }
        #else
        if (fread(grid[i], 1, GRIDWIDTH, fin) != GRIDWIDTH) {
            printf("Could not read all chars on the line\n");
            system("pause");
        }
        #endif
        fseek(fin, 1, SEEK_CUR);
    }
    for (i = 0; i < GRIDHEIGHT; ++i) {
        #if 1
        for (j = 0; j < GRIDWIDTH; ++j) {
            putc(grid[i][j], stdout);
        }
        #else
        if (fwrite(grid[i], 1, GRIDWIDTH, stdout) != GRIDWIDTH) {
            printf("Could not write all chars on the line\n");
            system("pause");
        }
        #endif
        printf("\n");
    }
    system("pause");
}

And here's test.txt:

Code:

*...*.....
......*...
...*...*..
..........
...*.F....
*.....*...
...*......
..C......*
...*.*....
.*.*......

What happens is that it writes the first line correctly, but then the following lines all comes after one extra new line too much; instead they miss their last char. So the print to stdout looks like this:

Code:

*...*.....

......*..

...*...*.

.........

...*.F...

*.....*..

...*.....

..C......

...*.*...

.*.*.....

Why? I have tried different implementations as well, as you can see from the preprocessing code, but it doesn't matter.

Use fgets() to read each line of text (including any trailing space or newline
Use a loop to copy valid data from that line to the corresponding row of your board.