9 who(1) who(1) 9 NNNNAAAAMMMMEEEE who - who is on the system? SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS who [-a] [-b] [-d] [-H] [-l] [-p] [-q] [-r] [-s] [-t] [-T] [-u] [_f_i_l_e] who am i who am I DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN who can list the user's name, terminal line, login time, elapsed time since activity occurred on the line, and the