curl HTTP POST looping on array of strings using bash scripting

Question

I would like to loop on an array of strings defined inside a bash script (no external feed of the input parameters from a file). The cURL command is working fine when outside the loop passing a string variable to it (see the following FIRST SCENARIO), however when I try to do something similar on a loop I fail to get the HTTP response (see the following SECOND SCENARIO), I get instead:

./curlScript.sh: line N: "paramOne" : [" foo bar"]: command not found
./curlScript.sh: line N+1: "paramOne" : "foo bar": command not found
./curlScript.sh: line N+2: "paramOne" : [{"detailOne":100.0, "detailTwo":"foo bar"}]: command not found

The idea is to pass JSON object in a HTTP POST request.

I've tried different quoting attempts: ', or ', or no quoting in different combinations around the variable $JSON_PARAM_V2, no way to get this working.

The curlScript.sh is executable (chmod +x).

What's wrong with the following script?

#!/bin/bash

IP_URL="localhost"
JSON_PARAM="foo bar"


# FIRST SCENARIO

curl -X POST -d '{ "paramOne" : "'"$JSON_PARAM"'" }' http://$IP_URL:8080/url_path --header "Content-Type:application/json" 

sleep 2;

# SECOND SCENARIO

jsonParametersArray=
(
    "\"paramOne\":[\"foo bar\"]"
    "\"paramOne\":\"foo bar\""
    "\"paramOne\":[{\"detailOne\":100.0,\"detailTwo\":\"foo bar\"}]\""

)

#for i in "${jsonParametersArray[@]}" do:
for ((i=0; i < ${#jsonParametersArray}; i++)) do

    JSON_PARAM_V2=i
    curl -X POST -d '{ "paramOne" : '"$JSON_PARAM_V2"' }' http://$IP_URL:8080/url_path --header "Content-Type:application/json" 

    sleep 2;

done

Matt · Accepted Answer · 2014-07-17 19:41:54Z

The jsonParametersArray definition needs to start on the same line you define the variable name. Using single quotes will make the JSON easier to define.

jsonParamOneArray=( 
  '["foo bar"]' 
  '"foo bar"' 
  '{"detailOne":100.0,"detailTwo":"foo bar"}'
)

Your commented out for line is the correct(ish) one but you are setting the full JSON paramater in your jsonParametersArray and then duplicating paramOne in the curl. Do one or the other.

for param in "${jsonParamOneArray[@]}"; do
   printf "\nCurling param [%s]\n" "$param"
   curl -X POST -d '{ "paramOne" : '"$param"' }' http://$IP_URL:8080/url_path --header "Content-Type:application/json"
   sleep 1
done

In the end it may be easier not to use bash when dealing with JSON and web API's

For example, Ruby has modules that eat this type of stuff up for breakfast. They deal with a lot of the edge cases that will trip up most shell implementations. Ruby also natively supports converting objects to and from JSON so you don't need to try and format it yourself.

require 'rest_client'

url = "http://localhost:8080/url_path"

paramOne_values = [
  ["foo bar"],
  "foo bar",
  { :detailOne => 100.0, :detailTwo => "foo bar" }
]

paramOne_values.each |value| do
  json = { "paramOne" => value }.to_json
  puts "Request param [#{json}]"
  response = RestClient.post url, json, :content_type => :json, :accept => :json
  JSON.load response
end

Collectives™ on Stack Overflow

curl HTTP POST looping on array of strings using bash scripting

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related