The "u" or "l" options can also be added to any combination of "a" and "x" in order to include more information about each process:

$ ps au
USER       PID %CPU %MEM   VSZ  RSS TTY      STAT START   TIME COMMAND
agriffis   403  0.0  0.0  2484   72 tty1     S     2001   0:00 -bash
chouser    404  0.0  0.0  2508   92 tty2     S     2001   0:00 -bash
root       408  0.0  0.0  1308  248 tty6     S     2001   0:00 /sbin/agetty 3
agriffis   434  0.0  0.0  1008    4 tty1     S     2001   0:00 /bin/sh /usr/X
chouser    927  0.0  0.0  2540   96 pts/1    S     2001   0:00 bash

$ ps al
  F   UID   PID  PPID PRI  NI   VSZ  RSS WCHAN  STAT TTY        TIME COMMAND
100  1001   403     1   9   0  2484   72 wait4  S    tty1       0:00 -bash
100  1000   404     1   9   0  2508   92 wait4  S    tty2       0:00 -bash
000     0   408     1   9   0  1308  248 read_c S    tty6       0:00 /sbin/ag
000  1001   434   403   9   0  1008    4 wait4  S    tty1       0:00 /bin/sh 
000  1000   927   652   9   0  2540   96 wait4  S    pts/1      0:00 bash