Add Show Tree View Of Processes And Subprocesses as a Unix TIL

unix/show-tree-view-of-processes-and-subprocesses.md

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+# Show Tree View Of Processes And Subprocesses
+
+Though you can cobble together a command on a MacOS Unix system to output a
+hierarchical tree view of a parent process and its descendent subprocesses, it
+is easier to [`brew install pstree`](https://github.com/FredHucht/pstree) and
+use that.
+
+Here is what I see when I run it for a _pid_ that corresponds to a `tmux`
+session that I have running locally:
+
+```bash
+❯ pstree 61690
+-+= 61690 lastword tmux new-session -d -s TIL -c /Users/lastword/dev/jbranchaud/til
+ |--= 63081 lastword /bin/zsh
+ |-+= 11428 lastword zsh
+ | \-+= 48511 lastword pstree 61690
+ |   \--- 48512 root ps -axwwo user,pid,ppid,pgid,command
+ |-+= 62345 lastword zsh
+ | \--= 06031 lastword claude
+ |--= 62364 lastword /bin/zsh
+ |-+= 62373 lastword zsh
+ | \--= 64407 lastword ssh my-app-staging
+ |-+= 61115 lastword /bin/zsh
+ | \-+= 61579 lastword overmind start -f Procfile.dev
+ |   \--- 61586 lastword tmux -C -L overmind-my-app-abc123 new -n web -s my-app -P -F %overmind-process #{pane_id} web #{pane_pid} /var/folders/zc/abc123/T/overmin
+ |--= 52237 lastword /bin/zsh
+ |--= 82608 lastword /bin/zsh
+ \--= 10796 lastword /bin/zsh
+```
+
+I was looking for a frozen `claude` process that was part of this session. And I
+found it about halfway down that list -- `06031`. Now I can run `kill` on that
+process as needed.
+
+For some additional context, I initially found the _pid_ for the `tmux` session
+by running `ps aux | grep tmux` and looking through those results.