Linear and Circular Convolution in Fourier Domain (DFT)
the following matlab/octave code gives the linear convolution result using frequency domain :

A = ((-1).^[0:79]').*hamming(80);    % input one
B = blackman(100);   % input two

C1 = conv(A,B);     % A * B (convolution) in time domain
C2 = real( ifft( fft(A,179).*fft(B,179) ) ); % convolution using freq domain


The output will be identical of length 179 samples: