How Can I Parse HTTP Requests and Responses from a Text File in Go?

Parse HTTP Requests and Responses from Text File in Go

In Go, parsing HTTP requests and responses from a text file involves leveraging the built-in HTTP parsing functions. To achieve this, one can employ the following approach:

func ReadHTTPFromFile(r io.Reader) ([]Connection, error) {
    // Establish a new buffered reader to process the input.
    buf := bufio.NewReader(r)

    // Define a slice that will store HTTP connection information.
    stream := make([]Connection, 0)

    // Loop indefinitely to parse request and response pairs until we reach the end of the file.
    for {
        // Attempt to parse an HTTP request using ReadRequest.
        req, err := http.ReadRequest(buf)

        // Check if we have reached the end of the file or an error occurred.
        if err == io.EOF {
            // Break out of the loop since we have reached the end of the file.
            break
        } else if err != nil {
            // Log the error and return the partially parsed stream.
            log.Println("Error parsing HTTP request:", err)
            return stream, err
        }

        // Now that we have a request, we need to parse the corresponding HTTP response.
        resp, err := http.ReadResponse(buf, req)

        // Check for any errors while parsing the response.
        if err != nil {
            // Log the error and return the partially parsed stream.
            log.Println("Error parsing HTTP response:", err)
            return stream, err
        }

        // Copy the response body to a new buffer to preserve it.
        var b bytes.Buffer
        io.Copy(&b, resp.Body)

        // Close the original response body and replace it with a new, non-closing one.
        resp.Body.Close()
        resp.Body = ioutil.NopCloser(&b)

        // Add the connection to our stream.
        stream = append(stream, Connection{Request: req, Response: resp})
    }

    // Return the parsed stream.
    return stream, nil
}

With this function, you can open a file containing HTTP requests and responses and parse them. For example:

func main() {
    // Open a file for reading.
    file, err := os.Open("http.txt")
    if err != nil {
        log.Fatal(err)
    }

    // Parse the HTTP requests and responses from the file.
    stream, err := ReadHTTPFromFile(file)
    if err != nil {
        log.Fatal(err)
    }

    // Dump a representation of the parsed requests and responses for inspection.
    for _, c := range stream {
        reqDump, err := httputil.DumpRequest(c.Request, true)
        if err != nil {
            log.Fatal(err)
        }
        respDump, err := httputil.DumpResponse(c.Response, true)
        if err != nil {
            log.Fatal(err)
        }
        fmt.Println(string(reqDump))
        fmt.Println(string(respDump))
    }
}

This code will read the contents of the "http.txt" file, parse the HTTP requests and responses, and dump their representation for inspection. The HTTP parsing functions provided by the Go standard library enable you to extract and manipulate requests and responses from a text file stream.

The above is the detailed content of How Can I Parse HTTP Requests and Responses from a Text File in Go?. For more information, please follow other related articles on the PHP Chinese website!