Automatically end each command in terminal with a different message or sound

Question

I installed SVOX pico2wave and created a script. Now when I enter:

speech "Hello world"

The computer text-to-voice engine says out loud "Hello world". Furthermore, I use in .bashrc the variable PROMPT_COMMAND defined as:

PROMPT_COMMAND="speech 'Command executed.'"

So the nice text-to-voice engine announces me loud that the command is executed, before returning the prompt in the terminal.

However, this gets boring after a while and I thought it would be really cool to end each command in terminal with the computer speaking a different line of text (think of the autopilot of Starship Enterprise).

So I created in .bashrc an array variable, with different messages:

array[0]="Shields at 90%"
array[1]="Engaging proton overdrive"
array[2]="Autopilot disengaged"
array[3]="Targetting solution available"
array[4]="Alert. Incoming missile."
array[5]="Deploying countermeasures."
array[6]="Firing torpedoes."
array[7]="Engaging auto-cannon."
array[8]="Severe damage on deck 17. Sealing off."
array[9]="Deploying repair droids to deck 17."

What I would like, is that each time I run a command in terminal, the variable PROMPT_COMMAND to be updated and read a different random line in the array.

I presume I need a loop, but I didn't know how to make it.

I would be most grateful for any help. Thank you.

Answer 1

Create a script and save it somewhere which contains your lines and the logic to choose a random line from your array and calling speech command on that line:

array[0]="Shields at 90%"
array[1]="Engaging proton overdrive"
array[2]="Autopilot disengaged"
array[3]="Targetting solution available"
array[4]="Alert. Incoming missile."
array[5]="Deploying countermeasures."
array[6]="Firing torpedoes."
array[7]="Engaging auto-cannon."
array[8]="Severe damage on deck 17. Sealing off."
array[9]="Deploying repair droids to deck 17."

line=${array[$RANDOM % ${#array[@]}]}
speech "$line"

Then in your .bashrc or .profile set PROMPT_COMMAND:

PROMPT_COMMAND="bash $HOME/PATH/TO/myscript.sh"

Just replace the speech with echo to get a messge instead of the voice.

Answer 2

Later Edit Tutorial:

Thanks to Ravexina's answer above, now the problem is solved and the solution works fantastically. I will give step-by-step instructions below, for the other people interested to make it work in Ubuntu 18.04

1. Install SVOX pico2wave package:

sudo apt-get install libttspico0 libttspico-utils libttspico-data libsox-fmt-mp3

2. Create the speech script

cd ~/scripts
gedit speech

and put this content inside, inserting the correct user in the path:

#!/bin/bash
pico2wave -l=en-US -w=/home/user/test.wav "$1"
aplay -q ~/test.wav
rm /home/user/test.wav

save and exit.

3. Create the shell_speech.sh script as indicated by Ravexina above:

gedit shell_speech

array[0]="Shields at 90%"
array[1]="Engaging proton overdrive"
array[2]="Autopilot disengaged"
array[3]="Targetting solution available"
array[4]="Alert. Incoming missile."
array[5]="Deploying countermeasures."
array[6]="Firing torpedoes."
array[7]="Engaging auto-cannon."
array[8]="Severe damage on deck 17. Sealing off."
array[9]="Deploying repair droids to deck 17."

line=${array[$RANDOM % ${#array[@]}]}
speech "$line"

save and exit.

4. Make the scripts executable and add their directory to PATH so that they could be called from everywhere:

chmod u+x ~/scripts/bin/speech
chmod u+x ~/scripts/bin/shell_speech
export PATH=$PATH:~/scripts

5. Modify .bashrc

gedit ~/.bashrc

add the following line:

PROMPT_COMMAND="bash shell_speech"

save and close

Note: you can add as many new lines as you want in the array in ~/scripts/bin/shell_speech