CODEWITHSUNDEEP
c
Giuliano Malatesta
Giuliano Malatesta

Reputation: 9

Segmentation fault (core dumped) when reading a file

I want to write a C program that can read this file containing a 3x3 matrix 

 1 2 3 
 4 5 6
 2 8 7

but I get: Segmentation fault (core dumped)

#include <stdio.h>

int main (int argc, char *argv[]){

    FILE *fp;
    int i, j;
    int mat[2][2];

    if (argc != 1) {
        if((fp = fopen(*++argv, "r")) == NULL) {
            printf("I can't open file %s\n", *argv);
            return 1;
        }
    }

    for(i=0,j=0; i < 3; i++, j++)
        fscanf(fp, "%d", &mat[i][j]);

    printf("%d",mat[2][2]);

    fclose(fp);
    return 0;
}

Upvotes: 0

Views: 82

Answers (1)

kiran Biradar
kiran Biradar

Reputation: 12732

Two problems.

  1. First problem.

    int mat[2][2];

    Is 2*2 matrix with indexes [0,1]. You need.

    int mat[3][3];

  2. As of now you are reading first 3 numbers into diagonal positions.
    What you need is

    for(i=0; i < 3; i++)
    for(j=0; j < 3; j++)
        fscanf(fp, "%d", &mat[i][j]);

Upvotes: 4

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