75
votes

My problem: Using the command line tool to curl my localhost server while sending some data along with my POST request is not working.

What seems to be causing the error: Imagine something like this

  1. curl -i -X POST -H 'Content-Type: application/json' -d '{"data1": "data goes here", "data2": "data2 goes here"}' http:localhost/path/to/api

Result of the returning data

curl: (6) Could not resolve host: application; No data record of requested type
curl: (6) Could not resolve host: data goes here,; No data record of requested type
curl: (6) Could not resolve host: data2; No data record of requested type
curl: (3) [globbing] unmatched close brace/bracket at pos 16

After some searching i figured out that problem couldn't be the sintax used for the request since it works on UNIX shells.

Are you possibly using Windows? That so looks like a completely broken shell that doesn't properly deal with single-quotes vs double-quotes. I just tried that command line and it worked fine on my linux box. http://curl.haxx.se/mail/archive-2011-03/0066.html

I tried to work around with those " escaping it \" but it still didn't work

2.

curl -i -X POST -H 'Content-Type: application/json' -d '{\"data1\": \"data goes here\", \"data2\": \"data2 goes here\"}' http: //localhost/path/to/api

3.

curl -i -X POST -H 'Content-Type: application/json' -d '{\"data1\": \"data goes here\", \"data2\": \"data2 goes here\"}' http: //localhost/path/to/api

So i gave up. Windows seems to messing up with the JSON object sent on POST

8
Please do not add [solved] to your question title. If you've figured out the answer to your question, you should post it as an answer.Cody Gray♦
Thank you for the warning @CodyGray. I'll correct my Post.Lothre1
If you have git installed on your machine, you can use the git bash for curl. It saves a lot of headaches.Brandon Bertelsen

8 Answers

129
votes

I ran into the same issue on my win7 x64 laptop and was able to get it working using the curl release that is labeled Win64 - Generic w SSL by using the very similar command line format:

C:\Projects\curl-7.23.1-win64-ssl-sspi>curl -H "Content-Type: application/json" -X POST http://localhost/someapi -d "{\"Name\":\"Test Value\"}"

Which only differs from your 2nd escape version by using double-quotes around the escaped ones and the header parameter value. Definitely prefer the linux shell syntax more.

51
votes

Another Alternative for the command line that is easier than fighting with quotation marks is to put the json into a file, and use the @ prefix of curl parameters, e.g. with the following in json.txt:

{ "syncheader" : {
    "servertimesync" : "20131126121749",
    "deviceid" : "testDevice"
  }
}

then in my case I issue:

curl localhost:9000/sync -H "Content-type:application/json" -X POST -d @json.txt

Keeps the json more readable too.

17
votes

Alternative solution: A More Userfriendly solution than command line:

If you are looking for a user friendly way to send and request data using HTTP Methods other than simple GET's probably you are looking for a chrome extention just like this one http://goo.gl/rVW22f called AVANCED REST CLIENT

For guys looking to stay with command-line i recommend cygwin:

I ended up installing cygwin with CURL which allow us to Get that Linux feeling - on Windows!

Using Cygwin command line this issues have stopped and most important, the request syntax used on 1. worked fine.

Useful links:

Where i was downloading the curl for windows command line?

For more information on how to install and get curl working with cygwin just go here

I hope it helps someone because i spent all morning on this.

11
votes

At least for the Windows binary version I tested, (the Generic Win64 no-SSL binary, currently based on 7.33.0), you are subject to limitations in how the command line arguments are being parsed. The answer by xmas describes the correct syntax in that setting, which also works in a batch file. Using the example provided:

curl -i -X POST -H "Content-Type: application/json" -d "{""data1"":""data goes here"",""data2"":""data2 goes here""}" http:localhost/path/to/api

A cleaner alternative to avoid having to deal with escaped characters, which is dependent upon whatever library is used to parse the command line, is to have your standard json format text in a separate file:

curl -i -X POST -H "Content-Type: application/json" -d "@body.json" http:localhost/path/to/api
6
votes
  1. Try to use double quotes (") instead of single ones (').
  2. To preserve JSON format quotes, try doubling them ("").
  3. To preserve quotes inside data, try to double-escape them like this (\\"").

    curl ... -d "{""data1"": ""data1 goes here"", ""data2"": ""data2 goes here""}"
    curl ... -d "{""data"": ""data \\""abc\\"" goes here""}"
    
3
votes

One more alternative cross-platform solution on powershell 6.2.3:

$headers = @{
    'Authorization' = 'Token 12d119ad48f9b70ed53846f9e3d051dc31afab27'
}

$body = @"
{
    "value":"3.92.0", 
    "product":"847"
}
"@


$params = @{
    Uri         = 'http://local.vcs:9999/api/v1/version/'
    Headers     = $headers
    Method      = 'POST'
    Body        = $body
    ContentType = 'application/json'

}

Invoke-RestMethod @params
0
votes

We can use below Curl command in Windows Command prompt to send the request. Use the Curl command below, replace single quote with double quotes, remove quotes where they are not there in below format and use the ^ symbol.

curl http://localhost:7101/module/url ^
  -d @D:/request.xml ^
  -H "Content-Type: text/xml" ^
  -H "SOAPAction: process" ^
  -H "Authorization: Basic xyz" ^
  -X POST
0
votes

The double quotes in JSON need to be escaped, and the whole JSON needs to be enclosed in double quotes. To do this without manual escaping or using an extra file for the JSON, you can use CMD's ability to replace strings in variables to escape " to \":

set json={"data1": "data goes here", "data2": "data2 goes here"}
curl -i -X POST -H 'Content-Type: application/json' -d "%json:"=\"%" http://localhost/path/to/api