The ancestry of a process

When it comes to viewing the heritage of a process, the go-to command is pstree. By itself, pstree will show the descendant processes. Using the -s argument it will show ancestor processes. A good trick to remember is slap, pstree -slap <PID>.

I personally like the format of ps and being the kind of person that likes to come up with one line tools, I created this little snippet.

{ TPID=$$; while [[ $TPID -ne 1 ]]; do ps -f $TPID | tail -n1; TPID=$(ps h -o ppid -p $TPID); done; ps -f $TPID|tac; } | tac

Saving it to use later we get this.

#!/bin/bash

{ 
        TPID=${1:-$$}; 
        while [[ $TPID -ne 1 ]]; do 
                ps -f $TPID | tail -n1; 
                TPID=$(ps h -o ppid -p $TPID); 
        done; 
        ps -f $TPID | tac; 
} | tac

This is what the two commands output.