How can a bash script detect support for window titling escape characters?

Question

I have a debug trap that runs every time I enter a command in bash that sets the window title to indicate what command is running. I'm leaving out all the configuration details and boil it down to:

export PS1="\[\e]0;$GENERATED_WINDOW_TITLE\a\]$GENERATED_PROMPT"

This works incredibly well, with only one snag: if the bash shell is running in an environment that does not support this feature, the GENERATED_WINDOW_TITLE is printed on the screen with each prompt. This happens any time I'm running bash from a non-X terminal.

How can bash tell if this escape sequence is supported?

Answer 1

I don't think there's a terminfo capability for that. In practice, testing the value of TERM should be good enough. That's what I do in my .bashrc and .zshrc, and I don't recall it being a problem.

case $TERM in
  (|color(|?))(([Ekx]|dt|(ai|n)x)term|rxvt|screen*)*)
    PS1=$'\e\]0;$GENERATED_WINDOW_TITLE\a'"$PS1"
esac