Is it possible to get the transfer function expression of the output voltage/input voltage of a circuit in SPICE? For example, I build a passive low pass filter circuit then I want the coefficient values of s of the transfer function in the output file. What command should i use?

One more thing, is there any output file (text file) in Multisim like output file in SPICE?

 

Yes, after you make the simulation spice opens a new window. In the new window's tool bar there an option 'trace', as I remember, click on it and then choose input and output voltages.