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

我可以通过查看curl文档来得到一个解决方案，该文档指定使用-来将输出输出到stdout。

curl -o - -I http://localhost

要用http返回代码获得响应，我可以这样做

curl -o /dev/null -s -w "%{http_code}\n" http://localhost

这对我来说很管用:

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

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

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

根据我的经验，我们通常这样使用旋度

curl -f http://localhost:1234/foo || exit 1

curl: (22) The requested URL returned error: 400 Bad Request

这样我们就可以在curl失败时使用管道，并且它还显示状态代码。