Bash - Update terminal title by running a second command

Question

On my terminal in Ubuntu, I often run programs which keep running for a long time. And since there are a lot of these programs, I keep forgetting which terminal is for which

Answer 1

Try this:

trap 'echo -ne "\033]2;$(history 1 | sed "s/^[ ]*[0-9]*[ ]*//g")\007"' DEBUG

Thanks to the history 1 it works even with complicated expressions like:

true && (false); echo $? | cat

For which approaches relying on $BASH_COMMAND or $@ fail. For example simon's displays:

true | echo $? | cat

Thanks to Gilles and simon for providing inspiration.