jsonify turns command line arguments into full featured JSON documents

jsonify

#!/bin/bash

# This tool turns command line arguments into full featured JSON documents
# author: Hendrik Bergunde <hbergunde@gmx.de> https://gist.github.com/hendrikb/

# Call jsonify --help for help
# Put this script somewhere into your $PATH variable to access it from anywhere

# Thanks for using this script - I love you all.


# useful functions

function usage() {
  echo 'jsonify <--[json-key-name] [json value] ... | OPTIONS>'
  echo
  echo '  jsonify takes --command-line-arguments and values and renders them as'
  echo '   a JSON document. :)'
  echo
  echo '  You need at least one pair of --json-key-name json-value which then'
  echo "   will be rendered into {'json-key-name': 'json-value'} "
  echo
  echo 'Options:'
  echo '   -p     pretty print the output'
  echo "   -t     add @timestamp field in the format `date '+%FT%R:%S%:z'`"
  echo '   -h     show this help'
}

function fail() {
  echo $1 1>&2
  echo
  exit $2
}

function argument_to_key() {
  echo $1 | sed -e 's/^--//'
}

function parse_flag() {
  echo $1 | sed -e 's/^-//'
}

function print() {
  if [ $PRETTY == true ] ; then
    echo $@
  else 
    echo -n $@
  fi
}

###### Validation of Arguments ########

if [ "$1" == "--help" ] || [ "$1" == "-h" ] ; then usage ; exit 0 ; fi

if [ -z "$1" ] || [ -z "$2" ] ; then fail 'You need at least two parameters!' 1 ; fi
if [[ $1 =~ ^[a-z] ]] ; then fail 'You need to specify at least one --argument' 2; fi

SHOW_TIMESTAMP=false
PRETTY=false

###### Parsing of Arguments ########

JSON_KEY_VALUES=()

while [ ! -z "$1" ] ; do
  if [[ $1 =~ ^--.+ ]] ; then 
    if [[ $1 =~ = ]] ; then  fail "Sorry, we do not support --keyname=value notation. Please use --keyname value :)" 4 ; fi
    if [ -z "$2" ] ; then fail "Missing value argument for $1 - aborting" 3 ; fi
    JSON_KEY_VALUES+=("\"`argument_to_key $1`\": \"$2\"")
    shift 2
  else
    if [[ $1 =~ ^-.+ ]] ; then 
      flag=`parse_flag $1`
      if [ "$flag" == "p" ] ; then PRETTY=true ; fi
      if [ "$flag" == "t" ] ; then SHOW_TIMESTAMP=true ; fi
      shift 1
    else
      fail "Don't know what to do with argument \"$1\" - please call for --help" 99 ;
    fi
  fi
done

###### Output ########

TIMESTAMP=`date "+%FT%R:%S%:z"`


i=0
print '{'
for row in "${JSON_KEY_VALUES[@]}"
do
    if [ $PRETTY == true ] ; then echo -en "\t" ; fi
    echo -n $row

    i=$((i+1))
    if [ ! $i -eq ${#JSON_KEY_VALUES[@]} ] || [ $SHOW_TIMESTAMP == true ] ; then echo -n ', ' ; fi
    if [ $PRETTY == true ] ; then echo; fi
done

if [ $SHOW_TIMESTAMP == true ] ; then
    if [ $PRETTY == true ] ; then echo -en "\t" ; fi
    echo -n  "\"@timestamp\": \"$TIMESTAMP\""
    if [ $PRETTY == true ] ; then echo; fi
fi
echo '}'