matrix rang for one- and twodimensional array

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#define EPS 1e-6

struct data {
    int lines, columns;
};

int fillStruct(const char *filename, struct data* size);

int fillArray(const char* filename, struct data size, double* matr, double ** matrix);
void printArray(struct data size, double* matr, double ** matrix);

void swap(struct data size, double * matr, int firstLine, int secondLine);
void swapix(struct data size, double** matrix, int firstLine, int secondLine);

void sumk(struct data size, double* matr, int firstLine, double k, int secondLine);
void sumkix(struct data size, double** matrix, int firstLine, double k, int secondLine);

void getTriangle(struct data size, double* matr);
void getTrianglix(struct data size, double** matrix);

int getRang(struct data size, double* matr);
int getRangix(struct data size, double** matrix);

int main() {
    struct data size;
    double* matr;
    double** matrix;
    int temp;
    //заполнение структуры
    temp = fillStruct("C:\\Users\\m video\\Desktop\\work with\\data_dat.txt", &size);
    if (temp == -1) {
        printf("file open issue\n");
        return -1;
    }
    if (temp == 1) {
        printf("not enough numbers in first line of file to fill struct\n");
        return -1;
    }
    if (size.lines == 1 || size.columns == 1) {
        printf("rang = 1\nrangix = 1\n");
        return 0;
    }

    matr = (double*)malloc(sizeof(double) * size.lines * size.columns);
    if (!matr) {
        printf("malloc error\n");
        return -1;
    }
    matrix = (double**)malloc(sizeof(double*) * size.lines);
    if (!matrix) {
        printf("malloc errorix\n");
        free(matr);
        return -1;
    }
    for (int i = 0; i < size.lines; i++) {
        matrix[i] = (double*)malloc(sizeof(double) * size.columns);
        if (!matrix[i]) {
            printf("some malloc error\n");
            for (int j = 0; j < i; j++)
                free(matrix[j]);
            free(matrix);
            free(matr);
            return -1;
        }
    }
    //заполнение матриц
    temp = fillArray("C:\\Users\\m video\\Desktop\\work with\\data_dat.txt", size, matr, matrix);
    if (temp == -1) {
        printf("file open issue v2\n");
        free(matr);
        for (int i = 0; i < size.lines; i++)
                free(matrix[i]);
        free(matrix);
        return -1;
    }
    if (temp!=0) {
        printf("wrong file data: one of two possible errors in line n %d\n1)size.lines > actual number of lines in file\n2)size.columns > actual number of columns in file\n", temp);
        free(matr);
        for (int i = 0; i < size.lines; i++)
                free(matrix[i]);
        free(matrix);
        return -1;
    }
    printArray(size, matr, matrix);
    getTriangle(size, matr);
    getTrianglix(size, matrix);
    printArray(size, matr, matrix);
    printf("rang = %d\nrangix = %d\n", getRang(size, matr), getRangix(size, matrix));
    free(matr);
    return 0;
}

int fillStruct(const char *filename, struct data* size) {
    FILE* f = fopen(filename, "r");
    char line[100];
    if (!f)
        return -1;
    fgets(line, 100, f);
    if (sscanf(line, "%d %d", &size->lines, &size->columns) != 2)
        return 1;
    fclose(f);
    return 0;
}

int fillArray(const char* filename, struct data size, double* matr, double ** matrix) {
    FILE* f = fopen(filename, "r");
    double temp;
    char litter[100];
    if (!f)
        return -1;
    fgets(litter, 100, f);
    for (int i = 0; i < size.lines; i++) {
        for (int j = 0; j < size.columns; j++) {
            if (fscanf(f, "%lf", &temp) != 1) {
                return i;
            }
            matr[i * size.columns + j] = temp;
            matrix[i][j] = temp;
        }
    }
    fclose(f);
    return 0;
}
void printArray(struct data size, double* matr, double ** matrix) {
    printf("matr:\n");
    for (int i = 0; i < size.lines; i++) {
        for (int j = 0; j < size.columns; j++)
            printf("%lf ", matr[i * size.columns + j]);
        printf("\n");
    }
    printf("matrix:\n");
    for (int i = 0; i < size.lines; i++) {
        for (int j = 0; j < size.columns; j++)
            printf("%lf ", matrix[i][j]);
        printf("\n");
    }
}

void swap(struct data size, double* matr, int firstLine, int secondLine) {
    double temp;
    for (int j = 0; j < size.columns; j++) {
        temp = matr[firstLine * size.columns + j];
        matr[firstLine * size.columns + j] = matr[secondLine * size.columns + j];
        matr[secondLine * size.columns + j] = temp;
    }
}
void swapix(struct data size, double** matrix, int firstLine, int secondLine) {
    double temp;
    for (int j = 0; j < size.columns; j++) {
        temp = matrix[firstLine][j];
        matrix[firstLine][j] = matrix[secondLine][j];
        matrix[secondLine][j] = temp;
    }
}

void sumk(struct data size, double* matr, int firstLine, double k, int secondLine){
    for (int j = 0; j < size.columns; j++)
        matr[secondLine * size.columns + j] +=k * matr[firstLine * size.columns + j];
}
void sumkix(struct data size, double** matrix, int firstLine, double k, int secondLine) {
    for (int j = 0; j < size.columns; j++)
        matrix[secondLine][j] += k * matrix[firstLine][j];
}

void getTriangle(struct data size, double* matr) {
    int i, j, k = 0, l;
    for (j = 0; j < size.columns; j++) {
        for (i = k; i < size.lines; i++) {
            if (fabs(matr[i * size.columns + j]) > EPS) {
                if (i == size.lines - 1) {
                    swap(size, matr, k, i);
                    k++;
                    break;
                }
                for (l = i + 1; l < size.lines; l++)
                    sumk(size, matr, i, -1 * matr[l * size.columns + j] / matr[i * size.columns + j], l);
                swap(size, matr, k, i);
                k++;
                break;
            }
        }
    }
}
void getTrianglix(struct data size, double** matrix) {
    int i, j, k = 0, l;
    for (j = 0; j < size.columns; j++) {
        for (i = k; i < size.lines; i++) {
            if (fabs(matrix[i][j]) > EPS) {
                if (i == size.lines - 1) {
                    swapix(size, matrix, k, i);
                    k++;
                    break;
                }
                for (l = i + 1; l < size.lines; l++)
                    sumkix(size, matrix, i, -1 * matrix[l][j] / matrix[i][j], l);
                swapix(size, matrix, k, i);
                k++;
                break;
            }
        }
    }
}

int getRang(struct data size, double* matr) {
    int result = 0;
    int i, j, k = 0;
    for (i = 0; i < size.lines; i++) {
        for (j = k; j < size.columns; j++) {
            if (fabs(matr[i * size.columns + j]) > EPS) {
                result++;
                break;
            }
        }
        if (j == size.columns - 1) {
            return result;
        }
        k = j+1;
    }
    return result;
}
int getRangix(struct data size, double** matrix) {
    int result = 0;
    int i, j, k = 0;
    for (i = 0; i < size.lines; i++) {
        for (j = k; j < size.columns; j++) {
            if (fabs(matrix[i][j]) > EPS) {
                result++;
                break;
            }
        }
        if (j == size.columns - 1)
            return result;
        k = j + 1;
    }
    return result;
}