C从文件中加载矩阵

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

struct Matrix{
    int row;
    int col;
    int *mat;
};
/*初始化一个r行c列的矩阵*/
struct Matrix matrix_initialize( int r, int c )
{
    struct Matrix m;
    m.row = r;
    m.col = c;
    (m.mat) = (int *) malloc( sizeof(int)*(m.row)*(m.col));
    return m;
}

/*打印矩阵到标准输出*/
void matrix_show( struct Matrix m )
{
    int i,j;
    for( i = 0; i<m.row; i++)
    {
        for(j = 0; j<m.col; j++)
        {
            printf("%d ",*(m.mat+i*(m.col)+j) );
        }
        printf("\n");
    }
} 

/*从文件加载矩阵，文件第一行为矩阵的行值和列值，以后为数据（int型）*/
struct Matrix* load( char *file_name, struct Matrix * pm )
{
    FILE *fp;
    if( !(fp = fopen( file_name, "r" ) ) )
        exit(-1);
    //struct Matrix *pm;
    printf("loading file %s...\n",file_name);
    fscanf(fp,"%d%d",&(pm->row),&(pm->col));
    pm->mat = (int *) malloc(sizeof(int)*(pm->row)*(pm->col));
    int i,j;
    for(i=0;i<pm->row;i++)
    {
        for(j = 0; j < pm->col; j++)
        {
            if( fscanf(fp,"%d",((pm->mat)+i*(pm->col)+j)) == EOF )
                exit(-1);
        }
    }
    fclose(fp);
    return pm;
}


int main()
{
    struct Matrix m;
    struct Matrix *pm = &m;
    pm = load("matrix.dat",pm);
    matrix_show(*pm);
    return 0;
}