Shell Programming and Scripting

I often need to change the gamma of my screen depending on the brightness in the room, and as I spend most of my time on a console I decided to write a couple of zsh function to do it and bind them to key input. It works, but with an undesirable side effect.

Whenever I press the keys to change the gamma, it displays the function name at the prompt and outputs the result of calling xgamma. It's easy enough to stop xgamma output when it changes, but what I really want is to stop the function name being entered into the zsh prompt and have them execute silently.

This is how I bound the keys in .zshrc:

Code:

source "${ZDOTDIR:-$HOME}/scripts/gamma/gamma"
zle -N increase_gamma
zle -N decrease_gamma
zle -N reset_gamma
bindkey -s '^{' '^qdecrease_gamma\n'
bindkey -s '^}' '^qincrease_gamma\n'
bindkey -s '^~' '^qreset_gamma\n'

These are the functions as they are declared in ~/scripts/gamma/gamma:

Code:

increase_gamma() {
    GAMMA_TEMP=$GAMMA_CURRENT
    (( GAMMA_CURRENT=$GAMMA_TEMP+0.1 ))
    xgamma -s -gamma $GAMMA_CURRENT 
}

decrease_gamma() {
    GAMMA_TEMP=$GAMMA_CURRENT
    (( GAMMA_CURRENT=$GAMMA_TEMP-0.1 ))
    xgamma -s -gamma $GAMMA_CURRENT
}

reset_gamma() {
    GAMMA_CURRENT=$GAMMA_DEFAULT
    xgamma -s -gamma $GAMMA_DEFAULT
}

GAMMA_CURRENT and GAMMA_DEFAULT are declared in .zshenv.

Is it possible to stop the functions names being displayed at the prompt when they execute, or is that something that can't be avoided?

Have you considered using xbindkeys and map to shell scripts?

You could then query current gamma from the script and adjust up or down as appropriate.