Galapagos: OSX Terminal Based Volume Utility

What is it?

Program used to control the volume in a Curses like interface for OSX.

Demonstration of setting the volume via the terminal based GUI.

The Source Code

https://github.com/jmercouris/galapagos_volume

How do I install it?

Download Galapagos, chmod +x the the file, and then run it! Alternatively to install from source, or to view the full installation instructions, checkout the repository: here.

The Need

There is currently a way to change the volume in OS X via the command line, but it is cumbersome and unintuitive. I wanted to improve upon that  method. These kinds of tools are important for maintaining a mental context, whenever you have to switch away from the active window you are breaking the mental context and will suffer a performance when trying to get back to what you are doing. If you can contain everything within one window, and do so conveniently without hassle (e.g. terminal tabs) you can have greatly improved focus and performance.

The Original Method

The original method looks like this:

• Get volume
  • Echos a number from 0 to 100
  • osascript -e 'output volume of (get volume settings)'
• Set volume
  • Where 50 is a number from 0 to 100
  • osascript -e 'set volume output volume 50'
• Get mute state
  • Echos a string of 'true' or 'false'
  • osascript -e 'output muted of (get volume settings)'
• Set mute state
  • Where 'true' can be 'true' or 'false'
  • osascript -e 'set volume output muted true'

Src: https://coderwall.com/p/22p0ja/set-get-osx-volume-mute-from-the-command-line

The New Method / Galapagos Usage

• volume
  • When started from the command line with no arguments, volume will produce a terminal GUI
• volume -v 80
  • set the volume to 80/100
• volume -v 65 -d input
  • set the input volume to 65/100
• volume -d input
  • show the input volume

The Development Story

The development story for this application was rather rough. It started off with merely learning how to call commands to set the volume in OS X via applescript. That is done in the following way

osascript -e 'output volume of (get volume settings)'

Knowing this, the dream was to eventually develop something similar to alsamixer within the console. It always seemed super great to me that you could do literally everything from a terminal if you wanted.

https://en.wikipedia.org/wiki/Alsamixer#/media/File:Alsamixer.png

This was a great interface, but it was overkill for what I was trying to do. Within applescript you are very limited in how you may manipulate the audio devices. Essentially you can only change the input and output volume. Despite this limitation I designed the application to be largely modular and changeable when the time arises that there is a new interface, or a new way of changing the volume discovered. To that end, I made an abstract AudioDevice class which looks like the following:

# Represents an OSX audio device, e.g. input, output
class AudioDevice:
    """
    A class responsible for representing & manipulating OSX audio devices
    """
    def __init__(self, name, set_volume_command, get_volume_command):
        self.name = name
        self.set_volume_command = set_volume_command
        self.get_volume_command = get_volume_command
        self.volume = self.get_volume()
    def set_volume(self, volume):
        # Constrain Volume to Valid Range
        if (volume > 100):
            volume = 100
        if (volume < 0):
            volume = 0
        # Copy Command arguments list into local version for modification
        local_command = self.set_volume_command[:]
        local_command[2] = self.set_volume_command[2].format(volume)
        process = subprocess.Popen(local_command, stdout = subprocess.PIPE)
        out, err = process.communicate()
        self.volume = volume
    def get_volume(self):
        process = subprocess.Popen(self.get_volume_command, stdout = subprocess.PIPE)
        out, err = process.communicate()
        # Set Local volume to reflect system reported volume
        self.volume = int(out)
        return self.volume

# Represents the Data in the program
class VolumeModel:
    """
    Populating the default OSX AudioDevices
    """
    def __init__(self):
        # List of audio devices
        audio_devices = self.audio_devices = []
        # AudioDevice Output
        get_volume_command = ['osascript', '-e', 'output volume of (get volume settings)']
        set_volume_command = ['osascript', '-e', 'set volume output volume {}']
        device = AudioDevice("Output", set_volume_command, get_volume_command)
        audio_devices.append(device)
        # AudioDevice Input
        get_volume_command = ['osascript', '-e', 'input volume of (get volume settings)']
        set_volume_command = ['osascript', '-e', 'set volume input volume {}']
        device = AudioDevice("Input", set_volume_command, get_volume_command)
        audio_devices.append(device)
    def get_audio_devices(self):
        return self.audio_devices

What does it look like?

Changing the output volume (black bar)

Changing the input volume (gray bar)

Demonstrating the command line argument functionality available

Thanks for reading!

I hope you enjoyed reading this article, and maybe you can also enjoy using the program yourself!