[SOLVED] POST request with Powershell 2.0 using cURL

Issue

Scenario

Among other things, Powershell 2.0 doesn't have the useful cmdlet Invoke-RestMethod.

I can't upgrade to version 3 and most examples I've found use version 3.

I have found this article, which seems, however, too complicated for my simple scenario.

I need to write a Powershell script that POSTs data in Json format, e.g.

{"Id":5,"Email":"test@com","DataFields":null,"Status":0}

What I've tried

I am able to GET data. This is one of the scripts I have tried.

curl -v --user username:password https://api.dotmailer.com/v2/account-info

But, when I try to POST, I can't figure out where to put the body of the message in the script. This is what I've got so far:

curl -v -X POST -H "Accept: application/json" -H "Content-Type: application/json" -u username:password -d '{"Id":5,"Email":"test@com","OptInType":0,"EmailType":0, "DataFields":null,"Status":0}' https://api.dotmailer.com/v2/contacts

which returns the following error:

{"message":"Could not parse the body of the request based on the content type \"application/json\" ERROR_BODY_DOES_NOT_MATCH_CONTENT_TYPE"}*

Question

Can anyone advise on how to POST Json data from Powershell using cURL?

Any pointers to why I get the error I mentioned in the Waht I've tried section would be much appreciated.

Thanks.

Solution

Note that the question is about the curl.exe external program, not about PowerShell's Invoke-WebRequest cmdlet (which, unfortunately, is aliased to curl in later PowerShell versions, preempting calls to the external program unless the .exe extension is explicitly specified (curl.exe ...).

Unfortunately and unexpectedly, you have to \-escape embedded " instances in a string you pass as an argument to an external program in Windows PowerShell and PowerShell (Core) up to v7.2.x.

That is, the following works only in v7.3+:

# Only works in PowerShell 7.3+
'{"Id":5,"Email":"test@com","DataFields":null,"Status":0}'

Windows PowerShell and PowerShell (Core) 7.2.x- require:

# Manual \-escaping of " required in
# *Windows PowerShell* and *PowerShell (Core) 7.2.x-*
'{\"Id\":5,\"Email\":\"test@com\",\"DataFields\":null,\"Status\":0}'

See this answer for more information.

Answered By - mklement0

Answer Checked By - Senaida (WPSolving Volunteer)