First version of nmcli_output to json

scan.sh

#!/usr/bin/env bash
#
# Scan availible wifi networks
# https://unix.stackexchange.com/questions/399222/jq-parse-colon-separated-value-pairs

nmcli_output=$(nmcli dev wifi | sed '$ d' | sed '1d')

#TODO use multi-line version of nmcli to better parse

# function for parsing nmcli output
function get_column {
  column=$(printf %s\\n "$nmcli_output" | awk -v column=$1 '
    NR==1 {
      i=1; p=1;
      while(match($0,/^[^ ]+ +/)) {
        a[i++] = p;
        p += RLENGTH;
        $0 = substr($0, RLENGTH+1);
      }
    }
    NR!=1 {
      text = substr($0, a[column], a[column+1] ? a[column+1]-a[column] : length);
      sub(text, / +$/, "");
      print text
    }')
    column=$(echo $column | sed -e 's/ /,/g')
    echo $column
}

# set all variables from nmcli
network=$(get_column 2)
mode=$(get_column 3)
chan=$(get_column 4)
rate=$(get_column 5)
signal=$(get_column 6)
bars=$(get_column 7)
security=$(get_column 8)

# generate json
echo "[" > /tmp/gen_json
network_iter=0
for i in $(echo $network | sed "s/,/ /g")
do
  network_iter=$(expr $network_iter + 1)

  # Get values for each attribute on each network
  network_instance=$(echo $network | cut -d"," -f $network_iter)
  mode_instance=$(echo $mode | cut -d"," -f $network_iter)
  chan_instance=$(echo $chan | cut -d"," -f $network_iter)
  rate_instance=$(echo $rate | cut -d"," -f $network_iter)
  signal_instance=$(echo $signal | cut -d"," -f $network_iter)
  bars_instance=$(echo $bars | cut -d"," -f $network_iter)
  security=$(echo $security | cut -d"," -f $network_iter)

  # Parse into json
  json="{
    \"network\": \"$network_instance\",
    \"mode\": \"$mode_instance\",
    \"chan\": \"$chan_instance\",
    \"rate\": \"$rate_instance\",
    \"signal\": \"$signal_instance\",
    \"bars\": \"$bars_instance\",
    \"security\": \"$security_instance\"
  }"
  echo "$json", >> /tmp/gen_json
done

# Remove last comma, change later?
perl -0777 -pi -e 's/(.*),(.*?)/\1\2/s' /tmp/gen_json
echo "]" >> /tmp/gen_json

# output json
cat /tmp/gen_json