5403 blue ~$ ps fx
  PID  TT  STAT      TIME COMMAND
46162  ??  S      0:00,01 sshd: szczepan@ttyp0 (sshd)
46174  ??  S      0:00,02 sshd: szczepan@ttypf (sshd)
46163  p0  Ss+    0:00,01 screen -RD
46165  pa  Ss+    0:00,02 /usr/local/bin/bash
46175  pf  Ss     0:00,03 -bash (bash)
46201  pf  R+     0:00,00 ps fx
5404 blue ~$ killall screen
5405 blue ~$ ps fx
  PID  TT  STAT      TIME COMMAND
46174  ??  S      0:00,04 sshd: szczepan@ttypf (sshd)
46175  pf  Ss     0:00,03 -bash (bash)
46213  pf  R+     0:00,00 ps fx
5406 blue ~$ ps fx
  PID  TT  STAT      TIME COMMAND
46174  ??  S      0:00,04 sshd: szczepan@ttypf (sshd)
46215  ??  S      0:00,01 sshd: szczepan@ttyp0 (sshd)
46216  p0  Ss+    0:00,01 screen -RD
46218  pa  Ss+    0:00,02 /usr/local/bin/bash
46175  pf  Ss     0:00,04 -bash (bash)
46219  pf  R+     0:00,00 ps fx
5407 blue ~$ ps fx