Passing json as command line argument in Unix

Question

I am trying to pass a json string as command line argument to my c++ application in a Unix environment.

.\SampleApp -j {\"speed\":\"15\",\"rpm\":\"100\",\"loc\":[\"-83.11\",\"42.11\"]}

I'm using getopt() function in my sample app to parse the arguments. At the output I am receiving only speed:15. But when I run the application as

.\SampleApp -j \"speed\":\"15\",\"rpm\":\"100\",\"loc\":[\"-83.11\",\"42.11\"]

it works. My question is how do I pass the json string with curly braces properly to the application. I tried using escape sequence, \{ , but it did not work.

Answer 1

Usually, it easier to use single quote when the text has double quotes

./SampleApp -j '{"speed":"15","rpm":"100","loc":["-83.11","42.11"]}'

Or over multiple lines for readability:

./SampleApp -j '
{
    "speed":"15",
    "rpm":"100",
    "loc":["-83.11","42.11"]
}'

Answer 2

You can do this by just passing the argument inside " . Also, it's ./ , not .\ .

./SampleApp -j "{\"speed\":\"15\",\"rpm\":\"100\",\"loc\":[\"-83.11\",\"42.11\"]}"