Scratch2Ext

Standard extension.json file look likes this
[
{ "name":"Pi GPIO", "type":"extension", "file":"piGPIOExtension.js", "md5":"pigpio.png", "url":"file:///usr/lib/scratch2/scratch_extensions/gpio.html", "tags":["hardware"]  },
{ "name":"Pi SenseHAT", "type":"extension", "file":"piSenseHATExtension.js", "md5":"pisensehat.png", "url":"file:///usr/lib/scratch2/scratch_extensions/sensehat.html", "tags":["hardware"]  }
]

I'm looking for grep/dsed/awk thingty bash script to add in


{ "name":"GrovePi", "type":"extension", "file":"piGrovePiExtension.js", "md5":"grovepi.png", "url":"file:///usr/lib/scratch2/scratch_extensions/grovepi.html", "tags":["hardware"]  },

but only if GrovePi is not already in the file - if it is in the file - then just leave alone

I'll be wanting to add a few more in future