ternary shell operator cli: https://stackoverflow.com/a/35512445/11944425

tern

#!/usr/bin/env bash
# Retrieved from https://stackoverflow.com/a/35512445/11944425
# solution provider Brad Parks https://stackoverflow.com/users/26510/brad-parks

function show_help()
{
  ME=$(basename "$0")
  IT=$(cat <<EOF

  Returns a ternary result

  usage: BOOLEAN VALUE_IF_TRUE VALUE_IF_FALSE
  
  e.g. 
  
  # YES
  $ME 1 YES NO                                

  # NO
  $ME 0 YES NO

  # NO
  $ME "" YES NO

  # YES
  $ME "STRING THAT ISNT BLANK OR 0" YES NO

  # INFO contains NO
  INFO=\$($ME 0 YES NO)
EOF
)
  echo "$IT"
  echo
  exit
}

if [ "$1" = "help" ] || [ "$1" = '?' ] || [ "$1" = "--help" ] || [ "$1" = "h" ]; then
  show_help
fi
if [ -z "$3" ]
then
  show_help
fi

# Set a default value for what is "false" -> 0
FALSE_VALUE=${4:-0}

function main
{
  if [ "$1" == "$FALSE_VALUE" ] || [ "$1" = '' ]; then
    echo $3
    exit;
  fi;

  echo $2
}

main "$1" "$2" "$3"

Install via:

curl --output-dir "/dev/shm" -o tern https://gist.githubusercontent.com/dmgolembiowski/ac6b4e12cb294b6912c2277922679c81/raw/c6e5a20626f687a785f08b7d293fb3c30123c2ea/tern
chmod +x /dev/shm/tern && \
sudo install -m 775 /dev/shm/tern /usr/local/bin/tern
rm /dev/shm/tern