Add output formats flag

[zph]

Hello!

I added extra output formats for printing device information:

Format	Description
human	current format (default)
cli	comma separated for grep/awk usage
json	json linewise format for jq

I also added a simple makefile to help with rebuilding the project from CLI.

I'm happy to contribute these changes back, but I'll admit I'm unfamiliar with writing good C. So please feel free to tweak the contribution to make it idiomatic and safe.

Thanks for writing this :). It solves an annoyance I had with wanting an easier way to switch audio devices.

[zuckschwerdt]

Looks good. Can you change this:

• remove char * FORMAT_CLI = "cli"; and put the string in the strcmp
• remove char * format;
• remove format = strdup(optarg);, use optarg in strcmp
• use strcmp instead of strncmp
• add a third strcmp for "human" and error in the else case (print and exit)

[zph]

@zuckschwerdt Will do, thank you for the feedback 👍 .

[zph]

$ ./build/Release/SwitchAudioSource -a -f json      
{"name": "Corsair VOID Wireless Gaming Dongle", "type": "input"}
{"name": "MacBook Pro Microphone", "type": "input"}
{"name": "DisplayPort", "type": "output"}
{"name": "Corsair VOID Wireless Gaming Dongle", "type": "output"}
{"name": "MacBook Pro Speakers", "type": "output"}

$ ./build/Release/SwitchAudioSource -a -f cli
Corsair VOID Wireless Gaming Dongle,input
MacBook Pro Microphone,input
DisplayPort,output
Corsair VOID Wireless Gaming Dongle,output
MacBook Pro Speakers,output

$ ./build/Release/SwitchAudioSource -a -f human
Corsair VOID Wireless Gaming Dongle (input)
MacBook Pro Microphone (input)
DisplayPort (output)
Corsair VOID Wireless Gaming Dongle (output)
MacBook Pro Speakers (output)

$ ./build/Release/SwitchAudioSource -a -f junk
Unknown format junk
Usage: ./build/Release/SwitchAudioSource [-a] [-c] [-t type] [-n] -s device_name
  -a             : shows all devices
  -c             : shows current device

  -f format      : output format (cli/human/json). Defaults to human.
  -t type        : device type (input/output/system).  Defaults to output.
  -n             : cycles the audio device to the next one
  -s device_name : sets the audio device to the given device by name
# exit_code=1

I've implemented your feedback and ^^ is a demonstration of the output.

Would you like me to squash this down to a single commit?

[zuckschwerdt]

Not needed. GitHub can squash on merge.

[deweller]

Looks good to me. Thanks!