while : ; do curl -sL -w "%{http_code} %{url_effective}\\n" http://host -o /dev/null; done

对于编程使用，我使用以下代码:

curlwithcode() {
    code=0
    # Run curl in a separate command, capturing output of -w "%{http_code}" into statuscode
    # and sending the content to a file with -o >(cat >/tmp/curl_body)
    statuscode=$(curl -w "%{http_code}" \
        -o >(cat >/tmp/curl_body) \
        "$@"
    ) || code="$?"

    body="$(cat /tmp/curl_body)"
    echo "statuscode : $statuscode"
    echo "exitcode : $code"
    echo "body : $body"
}

curlwithcode https://api.github.com/users/tj

显示如下信息:

statuscode : 200
exitcode : 0
body : {
  "login": "tj",
  "id": 25254,
  ...
}

我使用这个命令打印状态代码，而不输出任何其他结果。此外，它将只执行HEAD请求并遵循重定向(分别为-I和-L)。

curl -o -I -L -s -w "%{http_code}" http://localhost

这使得检查运行状况脚本中的状态代码非常容易:

sh -c '[ $(curl -o -I -L -s -w "%{http_code}" http://localhost) -eq 200 ]'

我发现这个问题是因为我想要独立访问响应和内容，以便为用户添加一些错误处理。

Curl允许您自定义输出。您可以打印HTTP状态代码以std输出并将内容写入另一个文件。

curl -s -o response.txt -w "%{http_code}" http://example.com

这允许您检查返回代码，然后决定是否值得打印、处理、记录响应等。

http_response=$(curl -s -o response.txt -w "%{http_code}" http://example.com)
if [ $http_response != "200" ]; then
    # handle error
else
    echo "Server returned:"
    cat response.txt    
fi

%{http_code}是一个由curl代替的变量。你可以做更多的事情，或者发送代码到stderr，等等。参见curl手册和——write-out选项。

-w, --write-out Make curl display information on stdout after a completed transfer. The format is a string that may contain plain text mixed with any number of variables. The format can be specified as a literal "string", or you can have curl read the format from a file with "@filename" and to tell curl to read the format from stdin you write "@-". The variables present in the output format will be substituted by the value or text that curl thinks fit, as described below. All variables are specified as %{variable_name} and to output a normal % you just write them as %%. You can output a newline by using \n, a carriage return with \r and a tab space with \t. The output will be written to standard output, but this can be switched to standard error by using %{stderr}.

https://man7.org/linux/man-pages/man1/curl.1.html

这对我来说很管用:

curl -Uri 'google.com' | select-object StatusCode

在末尾追加一行“http_code:200”，然后grep关键字“http_code:”并提取响应代码。

result=$(curl -w "\nhttp_code:%{http_code}" http://localhost)

echo "result: ${result}"   #the curl result with "http_code:" at the end

http_code=$(echo "${result}" | grep 'http_code:' | sed 's/http_code://g') 

echo "HTTP_CODE: ${http_code}"  #the http response code

在这种情况下，您仍然可以使用非静默模式/ verbose模式来获取有关请求的更多信息，例如curl响应体。