I want to run a command, for example
After each command, entered by the user.
- When the user enters a command, my global command should be executed, and later his command should be executed
- When the user enters a command, his command should be executed, and later my global command should be executed
How to accomplish the above two scenarios?
NB: I don’t want to use the prompt for this purpose, (leave the PS1 variable as is).
As l0b0 suggests, you can use
PROMPT_COMMAND to do your second request and you won’t have to touch
To do your first request, you can
trap 'echo "foobar"' DEBUG
For the second part you could use
declare -r PROMPT_COMMAND="echo 'foobar'": It is executed just before the prompt is displayed. Beware that it will not be run for each command in for example a pipe or command group.
Beware that any solution to this has the potential to mess things up for the user, so you should ideally only call commands which do not output anything (otherwise any output handling is virtually impossible) and which are not available to the user (to avoid them faking or corrupting the output).