[Tcl] How do I interact with web APIs and make HTTP requests in Tcl?

To interact with web APIs and make HTTP requests in Tcl, you can use the http package that is included with Tcl. The http package provides a set of commands for making HTTP requests and handling the responses.

Here's an example of how to make a GET request to a web API:

 1package require http
 2
 3set url "https://api.example.com/data"
 4set response [http::geturl $url]
 5
 6set status [http::status $response]
 7set data [http::data $response]
 8
 9if {$status == 200} {
10    # Process the response data
11    puts $data
12} else {
13    puts "Error: $status - [http::error $response]"
14}
15
16http::cleanup

In this example, we first load the http package using the package require command. Then, we set the url variable to the API endpoint we want to access.

The http::geturl command is used to make a GET request to the specified URL. It returns a handle to the response.

We can then use various commands provided by the http package to work with the response. In this example, we retrieve the status code using the http::status command and the response data using the http::data command.

Finally, we can process the response based on the status code. If it's a successful response (status code 200), we output the data. Otherwise, we display an error message along with the status code and any error message provided by the http::error command.

Don't forget to call http::cleanup at the end to clean up the resources used by the http package.

There are also other commands available in the http package, such as http::post, http::put, and http::delete, which allow you to make different types of HTTP requests. You can refer to the official Tcl documentation for more details on the usage of these commands.