如何通过 bash 脚本使用 netcat 获取 http 状态代码

Question

I have to write a bash script that has to include these conditions. I am newbee can you give me an advise please?

This script runs with "command and [parameter]". I give it to domain as a variable and script has to get this variable's status code with "nc" (I have not use cURL). If the status code is 200 (only), bash script print OK, otherwise script should exit with status code 7 without any prints words on screen.

I wrote this but when I use variables I am not able to get any result.

1-) this works (this is without variable, I know google responses 301 so I wrote grep 301)

#!/bin/bash

        STATUS=`printf 'GET / HTTP/1.1\r\nHost: google.com\r\n\r\n' | nc google.com 80 | awk '{print $2}' | grep '301'`
                if [ "$STATUS" -eq 301  ]; then
                echo "OK"
                else
                exit 7
                fi

2-) this is not work - please help me improve this script. I have to write with nc command to get response code and compare with 200.

#!/bin/bash

DOMAIN=google.com

        STATUS=`printf 'GET / HTTP/1.1\r\nHost: "$DOMAIN"\r\n\r\n' | nc "$DOMAIN" 80 | awk '{print $2}' | grep '301'`
                if [ "$STATUS" ]; then
                        echo "OK"
                else
                        exit 7
                fi

Answer 1

If have put together a small script. Hope that helps. PLEASE test before your production use:)

STATUS=$(printf "HEAD / HTTP/1.1\r\nUser-Agent: nc/0.0.1\r\nHost: $1\r\nAccept: */*\r\n\r\n" | nc $1 80 | sed -n 's/HTTP.* \(.*\) .*/\1/p' |grep $2)

if [ $? -eq 0 ]; then
  echo OK
else
  exit 7
fi

Your print command will work likewise:

STATUS=$(printf "HEAD / HTTP/1.1\r\nUser-Agent: nc/0.0.1\r\nHost: $1\r\nAccept: */*\r\n\r\n" | nc $1 80 | awk '{print $2}' |grep $2)

The grep in the way you are using it will print 200. That means we have to check in the if block against an actual value.

I am checking the last exit code. If the grep command was successful - means it has found 200 in the HTTP response code - the exit code will be 0.

I am issuing the script like ./demo.sh nginx.org 200