Add Open New Splits To The Current Directory as a tmux TIL

README.md

@@ -10,7 +10,7 @@ pairing with smart people at Hashrocket.
 
 For a steady stream of TILs, [sign up for my newsletter](https://crafty-builder-6996.ck.page/e169c61186).
 
-_1499 TILs and counting..._
+_1500 TILs and counting..._
 
 ---
 
@@ -1354,6 +1354,7 @@ _1499 TILs and counting..._
 - [Kill The Current Session](tmux/kill-the-current-session.md)
 - [List All Key Bindings](tmux/list-all-key-bindings.md)
 - [List Sessions](tmux/list-sessions.md)
+- [Open New Splits To The Current Directory](tmux/open-new-splits-to-the-current-directory.md)
 - [Open New Window With A Specific Directory](tmux/open-new-window-with-a-specific-directory.md)
 - [Organizing Windows](tmux/organizing-windows.md)
 - [Paging Up And Down](tmux/paging-up-and-down.md)

tmux/open-new-splits-to-the-current-directory.md

@@ -0,0 +1,37 @@
+# Open New Splits To The Current Directory
+
+I typically work in one project per tmux session. When I create a given tmux
+session, the default directory is for that project. All new windows and pane
+splits will open at that default directory. This generally is the default
+behavior I want.
+
+One caveat: I often open a new window within an existing session that I want
+anchored to another directory. This could be because I'm working in a monorepo
+and I need to work from a subdirectory for a specific package or app. Or it
+could be that I'm temporarily digging into another project and it isn't worth
+create a whole new session.
+
+Regardless of the reason, I run into a bit of friction with tmux's defaults.
+
+First I open the new window and `cd` to another project. After some working, I
+need to open a split pane, maybe to run a project command like a build or dev
+server. Hitting `prefix-"` (horizontal split) or `prefix-%` (vertical split)
+opens a pane with the shell defaulting back to the original directory, not the
+current directory.
+
+The trick to fixing this bit of friction is overriding the directory of pane
+splits. I can do that by adding the following to my `~/.tmux.conf`:
+
+```
+# Pane splits should open to the same path as the current pane
+bind '"' split-window -v -c "#{pane_current_path}"
+bind % split-window -h -c "#{pane_current_path}"
+```
+
+Make sure to run `tmux source-file ~/.tmux.conf` to apply these config changes.
+
+The `pane_current_path` is called a "Format" in tmux parlance. It resolves to
+the absolute path of the current pane's current directory. You can find all the
+formats in the manpage with this command: `man tmux | less +'/^FORMATS'`. You
+can also show yourself that this format resolves to what you expect by running
+`tmux display-message -p '#{pane_current_path}'`.