Add List The PID And Name Of Current Shell Process as a Unix TIL

unix/list-the-pid-and-name-of-current-shell-process.md

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+# List PID And Name Of Current Shell Process
+
+In Julia Evans' [How to add a directory to your
+PATH](https://jvns.ca/blog/2025/02/13/how-to-add-a-directory-to-your-path/),
+she shows off an odd-looking command for determining what shell (e.g. bash or
+zsh) you are currently running.
+
+```bash
+$ ps -p $$ -o pid=,comm=
+
+38105 -zsh
+```
+
+I already know I'm running `zsh`, but I thought this command was interesting
+enough to dig into and break down.
+
+- The `ps` command lists processes that "have controlling terminals"
+- The `$$` is a special shell variable representing the PID of the current process (try `echo $$`)
+- The `-p` flag allows you to specify a PID for `ps` to grab, in this case, the `$$` PID
+- The `-o` flag allows us to specify the output format, such as the PID and command name
+- The `=` after `pid` and `comm` tell `ps` to exclude headers from the output
+
+Additionally, I noticed that it output `-zsh` (not just `zsh`). That leading
+hyphen seems to indicate that [this `zsh` process is a _login
+shell_](https://unix.stackexchange.com/a/46856/5916). That means it was the
+process used to initiate an interactive shell session and something like the
+`.zprofile` would have been sourced as part of that.