I have to extract a matrix from a file through C and calculate the determinant of it. To do this for any matrix up to a 3x3 I'm sure i'll need to know the dimensions of the matrix but I'm pretty new to programming so I don't know what options I have.

If I have a .dat file with an unspecified matrix in it what can i do to find the dimensions of the matrix?

Just a push in the right direction would be useful as I don't know what my options are