cURL command works in git bash but not in cmd and powershell

Just read the error message:

Invoke-WebRequest Cannot bind parameter 'Headers'. Cannot convert the "Content-Type: application/json" value of type "System.String" to type "System.Collections.IDictionary".

In PowerShell, curl is an alias for the Invoke-WebRequest cmdlet. As the error points it out, the Header parameter must be a IDictionary, not a string. This is how it looks like in PowerShell:

@{"Content-Type"= "application/json"}

Some parameters are also different. This is how I would script the request:

Invoke-WebRequest `    -Uri "http://localhost:5678/api/findgen" `    -Headers @{"Content-Type"= "application/json"} `    -Body '{"a": "Val 1","b": "Val 2","c": "Val 3","d": "Val 4"}' `    -OutFile "file.json" `    -Method Post

So here is the adapted syntax as a one liner :

curl.exe "-X" "POST" "https://reqbin.com/echo/post/json" `"-H" "Content-Type: application/json" `"-d" '{\"a\": \"Val 1\",\"b\": \"Val 2\",\"c\": \"Val 3\",\"d\": \"Val 4\"}' `"-o" "file.json"

And a way a little more friendly for JSON :

curl.exe "-X" "POST" "https://reqbin.com/echo/post/json" `"-H" "Content-Type: application/json" `"-d" (@{a='Val 1';b='val 2';c='Val 3';d='Val 4'} | ConvertTo-Json -Compress) `"-o" "file.json"

I see those "Could not resolve host" only with C:\Windows\System32\curl.exe on Windows 10 (build 17063 or later), because of the way the Windows curl.exe native program interprets single and double quotes.

If you inverse/escape those quotes, it does work (on CMD)

C:\Windows\System32\curl -X POST http://localhost:5678/api/findgen \  -H "Content-Type: application/json" \    ^^^     double-quotes  -d "{\"a\": \"Val 1\",\"b\": \"Val 2\",\"c\": \"Val 3\",\"d\": \"Val 4\"}" -o "file.json"     ^^^     double quotes outside, escaped double-quotes inside: valid JSON

This is similar to "How do I POST JSON with Curl?"

On Powershell, I had to escape double quotes (backtick, as commented), and escape {}: {{}}

PS D:\> C:\Windows\System32\curl -X POST https://reqbin.com/echo/post/json `   -H "Content-Type: application/json" `   -d "{{`"login`":`"my_login`",`"password`":`"my_password`"}}"

Alternatively:

PS D:\> C:\Windows\System32\curl.exe -X POST https://reqbin.com/echo/post/json `>>    -H "Content-Type: application/json" `>>    -d '{{""login"":""my_login"",""password"":""my_password""}}'{"success":"true"}

From Steven's post:

PS D:\> C:\Windows\System32\curl.exe -X POST -H "Content-Type: application/json" `    -d '{""north"": ""each south""}' https://reqbin.com/echo/post/json{"success":"true"}

Using curl.exe alone means using the MingW Git for Windows curl.exe

PS D:\> curl.exe -X POST -H "Content-Type: application/json" `>>     -d '{""north"": ""each south""}' https://reqbin.com/echo/post/jsoncurl: (6) Could not resolve host: eachcurl: (3) unmatched close brace/bracket in URL position 6:south} https://reqbin.com/echo/post/json

You therefore need to escape curly brackets, and remove any space:

PS D:\> curl.exe -X POST -H "Content-Type: application/json" `>>     -d '{{"north":"each south"}}' https://reqbin.com/echo/post/json{"success":"true"}

Or, using spaces, with single quotes:

PS D:\> curl.exe -X POST -H "Content-Type: application/json" `>>     -d '{\"north\": \"each south\"}' https://reqbin.com/echo/post/json{"success":"true"}

On CMD If you want to keep those quotes unchanged, used the mingw curl.exe packaged with Git For Windows, at least on CMD.

C:\path\to\git\mingw64\bin\curl.exe -X POST http://localhost:5678/api/findgen \  -H 'Content-Type: application/json' \  -d '{"a": "Val 1","b": "Val 2","c": "Val 3","d": "Val 4"}' -o "file.json"     ^^^     You can keep the quotes as-is

As commented, in a Powershell session, curl itself is an alias for Invoke-WebRequest.

I tested it with:

PS D:\> Get-Alias -Name curlCommandType     Name                                               Version    Source-----------     ----                                               -------    ------Alias           curl -> Invoke-WebRequestPS D:\> curl -uri https://reqbin.com/echo/post/json `>>     -Method 'POST' -ContentType "application/json" `>>     -Body "{""login"":""my_login"",""password"":""my_password""}"StatusCode        : 200StatusDescription : OKContent           : {"success":"true"}RawContent        : HTTP/1.1 200 OK                    Connection: keep-alive                    CF-Cache-Status: DYNAMIC                    cf-request-id: 0917a97460000053c82aa69000000001                    Expect-CT: max-age=604800, report-uri="https://report-uri.cloudflare.com/cdn-cgi/bea...Forms             : {}Headers           : {[Connection, keep-alive], [CF-Cache-Status, DYNAMIC], [cf-request-id, 0917a97460000053c82aa69000000001], [Expect-CT, max-age=604800,                    report-uri="https://report-uri.cloudflare.com/cdn-cgi/beacon/expect-ct"]...}Images            : {}InputFields       : {}Links             : {}ParsedHtml        : System.__ComObjectRawContentLength  : 19