linux equivalent to AIX proctree command to show all child and parent processes of a given PID

Question

Sometimes I'm looking for an equivalent for the AIX proctree command which displays all children and all ancestors of a specified PID and can be sometimes quite useful for troubleshooting purposes. As an example here's an excerpt of the man page:

To display the ancestors and children of process 12312,
including children of process 0, enter:

   proctree -a 12312

The output of this command might look like this:
1    /etc/init                                  
   4954    /usr/sbin/srcmstr                    
      7224    /usr/sbin/inetd                   
         5958    telnetd -a                     
            13212    -sh                        
               14724    ./proctree -a 13212

Another useful form that I use sometimes is proctree $$ which will also show my current terminal, and whether I logged in via ssh or via console.

For clarification, I'm not looking for a script that emulates this on linux but an actual equivalent that may already be existent.

---

On linux, pstree shows all child processes of a specified PID, but the root will always be the specified PID (or init if no PID is specified and a complete tree will be shown).

Something like ps --forest -u "$username" does also not help as it only shows the processes of a given user, and it shows all of them - not only the ones of a given tree.

Answer 1

I think pstree -s 12312 gives what you want, if not in as nice a format.

Answer 2

Reposting my comment as an answer for better formatting.

Oh boy, seems I totally missed that in the man page. pstree -pas PID will show also parents, formatted as tree and include the PIDs of the processes.

An example:

[doktor5000@Mageia5]─[20:06:48]─[~] pstree -pas $$
systemd,1
  └─konsole,9515                    
      └─bash,9517
          └─pstree,9595 -pas 9517
[doktor5000@Mageia5]─[20:06:49]─[~]