How can I read the data from a file with structure like the one below into a multidimensional array of integers in C?
file:
3 4 30 29
23 43 4 43
I need put this inside of an "int** matrix" variable using dynamic allocation.
UPDATED:
I want an example code which I can go over and study the relation between the functionalities listed below:
- multidimensional arrays and their relation with pointer-to-pointer;
- dynamic allocation of memory and some explanation about it's use;
- how to deal with data coming from an external source that we don't know the size of, how separate the rows/cols into our array inside of the C program.
SHARING CODE:
int** BuildMatrixFromFile(char* infile, int rows, int cols){
FILE *fpdata; // deal with the external file
int** arreturn; // hold the dynamic array
int i,j; // walk thru the array
printf("file name: %s\n\n", infile);
fpdata = fopen(infile, "r"); // open file for reading data
arreturn = malloc(rows * sizeof(int *));
if (arreturn == NULL)
{
puts("\nFailure trying to allocate room for row pointers.\n");
exit(0);
}
for (i = 0; i < rows; i++)
{
arreturn[i] = malloc(cols * sizeof(int));
if (arreturn[i] == NULL)
{
printf("\nFailure to allocate for row[%d]\n",i);
exit(0);
}
for(j=0;j<cols;++j)
fscanf(fpdata, "%d", &arreturn[i][j]);
}
fclose(fpdata); // closing file buffer
return arreturn;
}
Thank you.
