bash: use \w instead of $PWD for the title

[jparise]

Discussed in #4601

^{Originally posted by piki January 4, 2025}
The PS1= variable in the bash integration for the title bar could use \w rather than $PWD to indicate the working directory.

The effect is to replace any leading instance of $HOME with a tilde, so /Users/patrick/code becomes ~/code. It also respects $PROMPT_DIRTRIM, if any. It looks cleaner to me, especially if there are multiple tabs open.

Implemented in this branch.

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From @jparise:

This sounds like a good improvement to me, and it looks like we do something similar in the zsh shell integration:

ghostty/src/shell-integration/zsh/ghostty-integration

Line 200 in f4a9b65

builtin print -rnu $_ghostty_fd \$'\\e]2;'\"\${(%):-%(4~|…/%3~|%~)}\"\$'\\a'"

The "set title" command is purely informational, so $PROMPT_DIRTRIM's abbreviation behavior shouldn't cause any functional issues. (We can rely on \e]7;kitty-shell-cwd://.. to report the full current working directory.)

I think it's possible some people might like to further customize their title, but they can do that in through their own shell configuration and disable our "title" shell integration feature.

[jparise]

@piki feel free to create a pull request based on your branch. If you're short on time, I can also make this change.

[piki]

@piki feel free to create a pull request based on your branch. If you're short on time, I can also make this change.

Opened as #4656