How can I fix JSON error on shell script? - json

I have a bash script which sends curl post requests. I want to pass data as bash script parameters. However one of the parameter has spaces in the string and it fails with the error below.
Error parsing JSON data.\n\tString not terminated on line
In shell script, I'm sending an argument like this format {"name":"'$2'"}
Could you please help me to solve that issue?
Thanks

jq is good not only for manipulating existing JSON data, but creating new data, as it does things like correctly handling characters that can't appear unescaped in JSON strings, and proper quoting. Something like
curl ... -d"$(jq -n --arg val "$2" '{name: $val}')"

It would be better if you add enough data while asking question.
I assume your json will be like
{
"name": "argument passed"
}
curl -XPOST "your/url/here" -H 'Content-Type:application/json' -d'{"name":"'$1'"}'
Save the above command as post_request.sh(Feel free to change the name).
Run using below comand.
sh post_request.sh "argument passed"
"argument passed" will be your name with space.

Related

Tell Json this all one line

I am writing a JSON template for AWS SSM document.
Once of the commands I am trying to run looks like this:
"ssh-keygen -q -t rsa -N '' <<< ""$'\n'"y" 2>&1 >/dev/null",
However, due to the "" after the <<< JSON thinks that this is a new line and is expecting a comma.
Is there a way I can tell JSON that that is a single command and need to be treated as a single line?
You need to escape the double quotes. So " inside your json string becomes \".

Passing variable to aws cli inline json

I wrote a script to create sqs resource on local stack. I wanted to pass a value that I get from one cli command to the next but inside an inline json. Following is the section of the script in question.
arn=$(aws --endpoint-url=http://localhost:4576 sqs get-queue-attributes \
--queue-url http://localhost:4576/my_dead_letter_queue_url \
--query 'Attributes.QueueArn' \
--output text)
aws --endpoint-url=http://localhost:4576 sqs create-queue \
--queue-name my_queue \
--attributes \
'{"RedrivePolicy":"{\"deadLetterTargetArn\":\"$arn\", \"maxReceiveCount\":\"5\"}"}'
So I'm trying to pass that "arn" variable but the cli is taking that as a string and trying to find a sqs with url "$arn" and fails. I also tried removing the quote. In that case, the error is malformed string.
Instead of the arn variable, if I use the arn value as string there, it works.
Can someone please show me how to pass that variable inside that inline json if it is possible?
Thank you for reading :)
Shahed
I was able to do the following with successful results, grant it it doesn't process the json (for that I'm just replacing tokens via sed), but I updated my example and tested it at least in bash with what I was doing:
#!/bin/bash
export awscmd="aws --region us-east-1 iam"
function setArn() {
${awscmd} list-policies --query 'Policies[?PolicyName==`'${1}'`].{ARN:Arn}' --output text
}
arn=$(setArn "some-policy-name")
echo '{"RedrivePolicy":"{"deadLetterTargetArn":"'$arn'", "maxReceiveCount":"5"}"}'
$ ./somearntest.sh
{"RedrivePolicy":"{"deadLetterTargetArn":"arn:aws:iam::############:policy/some-policy-name", "maxReceiveCount":"5"}"}
Notice the use of single tics to concatenate the output result outside of the string. This is in bash 4 and I removed the escaped \"s as I think that was added in error; ymmv.
The problem here is you are trying to expand a bash variable inside single quotes. Using single quotes like this is usually to pass a bunch of strings and unqoutable stuff as one argument. If you can't replace them with double quotes you'll have to resort to dirty eval hacks, which I do not recommend.
Here is an example:
$ arn=foobar
$ echo '{"RedrivePolicy":"{\"deadLetterTargetArn\":\"$arn\", \"maxReceiveCount\":\"5\"}"}'
{"RedrivePolicy":"{\"deadLetterTargetArn\":\"$arn\", \"maxReceiveCount\":\"5\"}"}
$ eval echo '{"RedrivePolicy":"{\"deadLetterTargetArn\":\"$arn\", \"maxReceiveCount\":\"5\"}"}'
{RedrivePolicy:{"deadLetterTargetArn":"foobar", "maxReceiveCount":"5"}}
For more information I suggest to check How eval works and Expansion of variables inside single quotes

Increment bash variable while evaluating it

I'm using curl to send some json data. Part of the data is a request counter that needs to be incremented after each call.
I would like to reduce the code below by incrementing it right after evaluating it. I'm not sure how to format the variable within the json string though.
Thank you in advance!
#!/bin/bash
reqcnt=0
curl http://myurl.com --data-binary '{"requestCounter":'${reqcnt}'}'
((reqcnt++))
Expected:
#!/bin/bash
reqcnt=0
curl http://myurl.com --data-binary '{"requestCounter":'${((reqcnt++)}'}'
Edit
Taking into account the great answer by Inian, I noticed there are cases where I need to save the output of curl. For some reason the arithmetic operation is not performed on the variable in that case:
res=$(curl http://myurl.com --data-binary {"requestCounter":'"$((reqcnt++))"'}')

How to get JSON data value in to separate variable using shell script

I am getting response from the below command in JSON format in .sh file (using shell script):
**curl https://api.flipkart.net/sellers/skus/$col1/listings -H "Content-Type: application/json" -H "Authorization: Bearer $value"**
Here is the response I am getting:
{"listingId":"LSMSW","skuId":"M7489","fsn":"ACCCQD","attributeValues":{"actual_stock_count":"1","mrp":"199","seller_listing_state":"current","procurement_sla":"2","zonal_shipping_charge":"0","stock_count":"10","local_shipping_charge":"0","listing_status":"ACTIVE","max_order_quantity_allowed":"3","fulfilled_by":"seller","fk_release_date":"2016-08-29 10:00:08","selling_price":"529","inventory_count":"10","national_shipping_charge":"0","sku_id":"M7489"},"listingValidations":null}
Now I want to extract all the value in a separate variable for reuse it
like:
LISTINGID='listing id value'
SKUID='skuId value'
and many more.
If anyone know the answer please comment with explanation.
Here is a solution using jq. If data.json contains the sample data then the following bash script
#!/bin/bash
jq -M -r '
.listingId
, .skuId
, .attributeValues.mrp
' data.json | \
while read -r listingId
read -r skuId
read -r mrp; do
echo "$listingId $skuId $mrp"
done
produces
LSMSW M7489 199
The jq command in the script writes out the specified attributes on separate lines which are read into bash variables by the successive read -r commands. It should be clear how to extend or modify this to meet your requirements – the primary constraint is that for each line written by jq there should be a corresponding read -r.
I am not aware of any bash json parsers. I would go with Python or Php and parse the Json string in one of these languages and export values from there. In Php there is the putenv() method.
Good luck!
Edit:
Check here
Parsing JSON with Unix tools

parsing json with shell script

Wanted to parse json:
{"FileStatus":"accessTime":1472892839430,"blockSize":134217728,"childrenNum":0,"fileId":17226,"group":"admin","length":115714,"modificationTime":1469649837471,"owner":"admin","pathSuffix":"","permission":"755","replication":2,"storagePolicy":0,"type":"FILE"}}
I tried something like this but not able to get it.
$ {"FileStatus":{"accessTime":1472892839430}} | jq '.FileStatus.accessTime'
Error:
-bash: {FileStatus:{accessTime:1472892839430}}: command not found`
Can someone help me to parse this whole json.
To make a command read a string on stdin in bash, use a "here string" like this:
$ jq '.FileStatus.accessTime' <<<'{"FileStatus":{"accessTime":1472892839430}}'
1472892839430
Also, you need to properly quote the text, so that bash doesn't try to interpret in some way you don't intend. When you want to preserve it literally, use single quotes (').