Making Network Requests with Curl on macOS Tahoe
curl (Client URL) is a command-line tool for transferring data to or from a server. On macOS Tahoe, it is pre-installed and essential for testing APIs, downloading files, and debugging network issues.
Basic GET Requests
The simplest use of curl is to retrieve the content of a URL.
curl https://www.example.comThis prints the HTML source of the page to your terminal.
Downloading Files
To save the output to a file instead of printing it, use the -O (uppercase letter O) or -o (lowercase letter o) flags.
Save with Original Filename (-O)
This saves the file using the name specified in the URL.
curl -O https://example.com/image.pngSave with Custom Filename (-o)
This allows you to specify the output filename.
curl -o my_image.png https://example.com/image.pngInspecting Headers
To view the HTTP headers returned by a server without downloading the body content, use the -I (Head) flag. This is useful for checking server status codes or content types.
curl -I https://www.google.comOutput Example:
HTTP/2 200
content-type: text/html; charset=ISO-8859-1
...Sending Data (POST Requests)
curl is widely used for interacting with REST APIs. You can send data using the -d flag, which defaults the request method to POST.
curl -d "param1=value1¶m2=value2" https://api.example.com/resourceSending JSON Data
When working with modern APIs, you often need to send JSON and set the Content-Type header.
curl -H "Content-Type: application/json" \
-d '{"username":"tahoe_user","active":true}' \
https://api.example.com/users-H: Adds a custom header.-d: Sends the data payload.
Handling Redirects
By default, curl does not follow HTTP redirects (like 301 or 302). To follow redirects automatically, use the -L flag.
curl -L http://google.comVerbose Mode
If a request is failing, use -v to see the complete handshake, headers sent, and headers received.
curl -v https://example.comFor more networking tools, refer to Networking Commands on macOS Tahoe.