How can I use testnpn to get all the npn equivalent class of one cell, or get whether two cell is npn equivalent

[youth1forever]

I try testnpn -A 1 -N 6 blif/test.txt, the ouput is
Applying exact NPN to 2 funcs of 6 vars... Classes = 2 Time = 0.00 sec
,and the content in inverter.txt is

00000 1
11111 0

1. I wonder whether the format of is correct. Help manual says

<file>   : a text file with truth tables in hexadecimal, listed one per line,
                   or a binary file with an array of truth tables (in this case,
                   -N <num> is required to determine how many functions are stored)

Can anyone give a sample of input file?
2. In my understanding, the ouput "Applying exact NPN to 2 funcs of 6 vars... Classes = 2 Time = 0.00 sec" means the two truth table in test.txt are in different npn class. Is my understanding correct?
3. Whether npntest has option to compute all the npn equivalent class of one input cell, and output to a file?