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

一行代码，只是为了获得状态代码:

curl -s -i https://www.google.com | head -1

将其更改为head -2也会给出时间。

如果你想要一个while-true循环，它会是:

URL="https://www.google.com"

while true; do
    echo "------"
    curl -s -i $URL | head -2
    sleep 2;
done

直到您执行cmd+C(或Windows中的ctrl+C)。

------
HTTP/2 200
date: Sun, 07 Feb 2021 20:03:38 GMT
------
HTTP/2 200
date: Sun, 07 Feb 2021 20:03:41 GMT
------
HTTP/2 200
date: Sun, 07 Feb 2021 20:03:43 GMT
------
HTTP/2 200
date: Sun, 07 Feb 2021 20:03:45 GMT
------
HTTP/2 200
date: Sun, 07 Feb 2021 20:03:47 GMT
------
HTTP/2 200
date: Sun, 07 Feb 2021 20:03:49 GMT

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。

详细模式会告诉你一切

curl -v http://localhost

要获得响应代码和响应:

$ curl -kv https://www.example.org

要得到响应代码:

$ curl -kv https://www.example.org 2>&1 | grep -i 'HTTP/1.1 ' | awk '{print $3}'| sed -e 's/^[ \t]*//'

2>&1:错误存储在输出中，用于解析 Grep:从输出中过滤响应代码行 Awk:从响应代码行中过滤响应代码 Sed:删除前导空白

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 ]'