$ gcc -o blas3 -Wall blas-3.c -lm -lblas -std=gnu99 

Compilation finished at Tue Nov 20 13:09:12



$ ./blas3 
Matrix A (3 x 5) is:
  1.0000  0.7290  0.5314  0.3874  0.2824
  0.9000  0.6561  0.4783  0.3487  0.2542
  0.8100  0.5905  0.4305  0.3138  0.2288

Matrix B (5 x 4) is:
  1.0000  0.5905  0.3487  0.2059
  0.9000  0.5314  0.3138  0.1853
  0.8100  0.4783  0.2824  0.1668
  0.7290  0.4305  0.2542  0.1501
  0.6561  0.3874  0.2288  0.1351

Matrix C (3 x 4) = AB is:
  2.5543  1.5083  0.8906  0.5259
  2.2989  1.3575  0.8016  0.4733
  2.0690  1.2217  0.7214  0.4260