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Make a curl call

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In this section, you’ll use curl to make the same weather API requests you made previously with Postman. If you haven’t installed curl, see curl intro and installation first.

Activity 2d: Make the OpenWeatherAPI request using curl

  1. Assuming you completed the exercises in the Postman tutorial, go back into Postman.
  2. On any call you’ve configured, and below the Save button in Postman, click the Code link.
  3. In the Generate Code Snippets dialog box, select cURL from the drop-down list, and then click Copy to Clipboard.

    The Postman code for the OpenWeatherMap weather request in curl looks as follows:

    curl -X GET \
      'https://api.openweathermap.org/data/2.5/weather?zip=95050&units=imperial&appid=fd4698c940c6d1da602a70ac34f0b147' \
      -H 'Accept: */*' \
      -H 'Accept-Encoding: gzip, deflate' \
      -H 'Cache-Control: no-cache' \
      -H 'Connection: keep-alive' \
      -H 'Host: api.openweathermap.org' \
      -H 'Postman-Token: 8a9aeae7-f063-42e8-b0e3-09d1a7069bd5,62f56707-3a65-4d68-a774-8e677ef4487e' \
      -H 'User-Agent: PostmanRuntime/7.15.2' \
      -H 'cache-control: no-cache'
    

    Postman adds its own header information (designated with -H). Do the following:

    • Remove all the header (-H) tags.
    • Remove the backslashes (\) (these are just added for readability).
    • Put everything on one line
    • If you’re on Windows, change the single quotation marks to double quotation marks.

    Here’s the same curl call with these modifications:

    curl -X GET "https://api.openweathermap.org/data/2.5/weather?zip=95050&units=imperial&appid=fd4698c940c6d1da602a70ac34f0b147"
    
  4. curl is available on Mac and Windows 10 by default. (If you’re on an older Windows machine that doesn’t have curl, see installing curl here for details.)

  5. Go to your Terminal (Mac) or Command Prompt (Windows).

    You can open your Terminal / Command Crompt by doing the following:

    • If you’re on Windows, go to Start and search for cmd to open up the command prompt. Paste in the curl request and then press Enter. (If you can’t paste it in, look for paste options on the right-click menu.)

    • If you’re on a Mac, open Terminal by pressing Cmd + spacebar and typing Terminal. (Or go to Applications > Utilities > Terminal). (You could also use iTerm.) Paste in the curl request and then press Enter.

    The response from the OpenWeatherMap weather request should look as follows:

    {"coord":{"lon":-121.95,"lat":37.35},"weather":[{"id":802,"main":"Clouds","description":"scattered clouds","icon":"03d"}],"base":"stations","main":{"temp":68.34,"pressure":1014,"humidity":73,"temp_min":63,"temp_max":72},"visibility":16093,"wind":{"speed":3.36},"clouds":{"all":40},"dt":1566664878,"sys":{"type":1,"id":5122,"message":0.0106,"country":"US","sunrise":1566653501,"sunset":1566701346},"timezone":-25200,"id":0,"name":"Santa Clara","cod":200}
    

    This response is minified. You can un-minify it by going to a site such as JSON pretty print, or if you have Python installed, you can add | python -m json.tool at the end of your cURL request to minify the JSON in the response (see this Stack Overflow thread for details).

  6. If you want additional practice, make a similar curl request for the 5 day forecast request that you also have in Postman. And another curl request for the third OpenWeatherMap API request you made in Postman.

Note about single and double quotes with Windows curl requests

If you’re using Windows to submit a lot of curl requests, and the curl requests require you to submit JSON in the request body, you might run into issues with single versus double quotes. The problem is that request body content is often formatted in JSON, which requires double quotes. Since you can’t use double quotes inside of other double quotes, you’ll run into issues in submitting curl requests in these scenarios.

Here’s the workaround. If you have to submit body content in JSON, you can store the content in a JSON file. Then you reference the file with an @ symbol, like this:

curl -H "Content-Type: application/json" -H "Authorization: 123" -X POST -d @mypostbody.json http://endpointurl.com/example

Here curl will look in the existing directory for the mypostbody.json file. (You can also reference the complete path to the JSON file on your machine.)

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