如何使用 Curl 检索真正的重定向位置标头？不使用 {redirect_url}

Question

我意识到 Curl {redirect_url} 并不总是显示相同的重定向 URL。例如，如果 URL 标头是Location: https:/\example.comthis 将重定向到https:/\example.com但 curl {redirect_url} 显示redirect_url: https://host-domain.com/https:/\example.com并且它不会显示响应真实位置标头。（我喜欢看到真实的location:结果。）

这是我正在使用的 BASH：

#!/bin/bash
# Usage: urls-checker.sh domains.txt
FILE="$1"
while read -r LINE; do
     # read the response to a variable
     response=$(curl -H 'Cache-Control: no-cache' -s -k --max-time 2 --write-out '%{http_code} %{size_header} %{redirect_url} ' "$LINE")
     # get the title
     title=$(sed -n 's/.*<title>\(.*\)<\/title>.*/\1/ip;T;q'<<<"$response")
     # read the write-out from the last line
     read -r http_code size_header redirect_url < <(tail -n 1 <<<"$response")
     printf "***Url: %s\n\n" "$LINE"
     printf "Status: %s\n\n" "$http_code"
     printf "Size: %s\n\n" "$size_header"
     printf "Redirect-url: %s\n\n" "$redirect_url"
     printf "Title: %s\n\n" "$title"
     # -c 20 only shows the 20 first chars from response
     printf "Body: %s\n\n" "$(head -c 100 <<<"$response")"
done < "${FILE}"

我如何才能printf "Redirect-url:在location: header不使用原始请求的情况下redirect_url？

Answer 1

要读取Location服务器返回的确切标头字段值，您可以将-i/--include选项与grep.

例如：

$ curl 'http://httpbin.org/redirect-to?url=http:/\example.com' -si | grep -oP 'Location: \K.*'
http:/\example.com

或者，如果您想读取所有headers、content和--write-outvariables行（根据您的脚本）：

response=$(curl -H 'Cache-Control: no-cache' -s -i -k --max-time 2 --write-out '%{http_code} %{size_header} %{redirect_url} ' "$url")

# break the response in parts
headers=$(sed -n '1,/^\r$/p' <<<"$response")
content=$(sed -e '1,/^\r$/d' -e '$d' <<<"$response")
read -r http_code size_header redirect_url < <(tail -n1 <<<"$response")

# get the real Location
location=$(grep -oP 'Location: \K.*' <<<"$headers")

完全集成到您的脚本中，如下所示：

#!/bin/bash
# Usage: urls-checker.sh domains.txt
file="$1"
while read -r url; do
    # read the response to a variable
    response=$(curl -H 'Cache-Control: no-cache' -s -i -k --max-time 2 --write-out '%{http_code} %{size_header} %{redirect_url} ' "$url")

    # break the response in parts
    headers=$(sed -n '1,/^\r$/p' <<<"$response")
    content=$(sed -e '1,/^\r$/d' -e '$d' <<<"$response")
    read -r http_code size_header redirect_url < <(tail -n1 <<<"$response")

    # get the real Location
    location=$(grep -oP 'Location: \K.*' <<<"$headers")

    # get the title
    title=$(sed -n 's/.*<title>\(.*\)<\/title>.*/\1/ip;T;q'<<<"$content")

    printf "***Url: %s\n\n" "$url"
    printf "Status: %s\n\n" "$http_code"
    printf "Size: %s\n\n" "$size_header"
    printf "Redirect-url: %s\n\n" "$location"
    printf "Title: %s\n\n" "$title"
    printf "Body: %s\n\n" "$(head -c 100 <<<"$content")"
done < "$file"