Cfrtjryk

I have an application that during installation runs a bunch of processes via screen, so I can see those if attached to the screen, however I don't see those via "ps -ef" or "ps auxww". How can I list all the processes running inside of screen ?

Thanks.

start cmd: # screen -ls

There is a screen on:

        24525.pts-0.syscontrol  (Attached)

start cmd: # pstree -p 24525

screen(24525)─┬─bash(10773)───su(10790)───bash(10791)

              ├─bash(10863)───pstree(11099)

              └─bash(24526)

Using pstree greatly simplifies the problem, but some clarification might help.

When you start screen, it runs two processes, screen (the parent) and SCREEN (the child):

• The -ls option of screen shows the session identifier with the child's process-id.


• You should list the parent process-id for consistency.


• It helps to show the argument list; pstree can do this.


• You could have multiple screen sessions on the same machine.

Tying these together calls for a script. Here is an example:

# $Id: ps-screen,v 1.1 2016/10/23 22:19:56 tom Exp $

# http://unix.stackexchange.com/questions/172347/list-processes-running-inside-of-screen-manager-with-with-vt100-ansi-terminal-e

screen -ls | awk '/[0-9]+./{print;}' | while read session

do

    child=$(echo "$session" | awk '{sub("..*","",$1); print $1;}')

    printf '%sn' "$session"

    parent=$(ps -p $child -o ppid=)

    pstree -p -a $parent

done

and example output, for two sessions:

~ (101) ps-screen 

38142.pts-1.vmw-debian7-64      (10/23/2016 06:20:28 PM)        (Attached)

screen,38141

  └─screen,38142

      └─tcsh,38143

          └─ps-screen,38161 /users/tom/bin/ps-screen

              └─ps-screen,38164 /users/tom/bin/ps-screen

                  └─pstree,38169 -p -a 38141

3975.pts-0.vmw-debian7-64       (10/23/2016 06:15:28 AM)        (Attached)

screen,3974

  └─screen,3975

      ├─tcsh,5002

      │   └─ded,19926 /usr/build//ncurses

      │       └─vile,24647 /usr/build/ncurses/ncurses-6.0-20161029/NEWS

      └─tcsh,36551

          └─ded,36569 /tmp

Further reading:

• 
  pstree - display a tree of processes (Linux)


• 
  pstree - display a tree of processes (FreeBSD)

Retrieve tty(pty) from screen -ls and then, ps -t ttyname or ps t ttyname will display process list associated with ttyname.

ps(1) manpage on Ubuntu
screen(1) manpage on Ubuntu