2 个相等的字符串（预期状态和当前状态）评估为 false

Question

我有一个**bash脚本来设置UFW，预期输出如下:

user@host:~$ sudo ufw status verbose
Status: active
Logging: on (low)
Default: deny (incoming), allow (outgoing), disabled (routed)
New profiles: skip

To                         Action      From
--                         ------      ----
22/tcp                     LIMIT IN    Anywhere                  
80/tcp                     ALLOW IN    Anywhere                  
443/tcp                    ALLOW IN    Anywhere                  
22/tcp (v6)                LIMIT IN    Anywhere (v6)             
80/tcp (v6)                ALLOW IN    Anywhere (v6)             
443/tcp (v6)               ALLOW IN    Anywhere (v6)

我创建了一个测试函数来验证输出是否符合预期。我手动将输出复制到一个变量中，并将输出存储在另一个变量中，这样我就可以按如下方式比较这两个变量：

function test() {
    # Verify that output is as excpeted
    local output="$(sudo ufw status verbose)"
    local expected="Status: active Logging: on (low) Default: deny (incoming), allow (outgoing), disabled (routed) New profiles: skip To Action From -- ------ ---- 22/tcp LIMIT IN Anywhere 80/tcp ALLOW IN Anywhere 443/tcp ALLOW IN Anywhere 22/tcp (v6) LIMIT IN Anywhere (v6) 80/tcp (v6) ALLOW IN Anywhere (v6) 443/tcp (v6) ALLOW IN Anywhere (v6)"

    # echo
    # echo $output
    # echo
    # echo $expected
    # echo

    if [[ "$output" == "$expected" ]]; then
        echo "UFW setup: output was as expected"
    else
        echo "UFW setup: output NOT as expected!"
        echo "Please check UFW status before coninuing:"
        echo
        sudo ufw status verbose
    fi

输出：

luc@E580-debian:~$ test
UFW setup: output NOT as expected!
Please check UFW status before coninuing:

Status: active
Logging: on (low)
Default: deny (incoming), allow (outgoing), disabled (routed)
New profiles: skip

To                         Action      From
--                         ------      ----
22/tcp                     LIMIT IN    Anywhere                  
80/tcp                     ALLOW IN    Anywhere                  
443/tcp                    ALLOW IN    Anywhere                  
22/tcp (v6)                LIMIT IN    Anywhere (v6)             
80/tcp (v6)                ALLOW IN    Anywhere (v6)             
443/tcp (v6)               ALLOW IN    Anywhere (v6)

据我所知，它们是完全一样的，但我也不知道是否有办法检查是否是隐藏字符导致的。或者，如果有办法 remove/replace 他们。

Answer 1

你是在比较硬的方式。您对 UFW 输出中的 /tabs /spaces 一无所知。这将是更专业的方法。请根据您的需要进行调整：

vim ./check_ufw.sh

#!/usr/bin/env bash
#:: Author: pr0logas
#:: Date: 2020-08-20
#:: Description: This program checks if the UFW firewall rules have not changed.

expected_output_file='/tmp/ufw_original.txt'
current_output_file='/tmp/ufw_current.txt'

echo "Just pushing some text as original UFW input to make FAILURE" > $expected_output_file

function check_diff() {
        ufw status numbered verbose > $current_output_file
        diff -q $expected_output_file $current_output_file 1> /dev/null

        if [[ $?  == "0" ]]; then
                echo "SUCCESS! UFW rules are the same."
        else
                echo "FAIL! UFW rules differ, attention needed!"
                exit 1
        fi
}

check_diff

为了 100% 确定所需的输出，我建议您第一次将当前输出复制为原始输入，如下所示：

cat /tmp/ufw_current.txt > /tmp/ufw_original.txt

然后评论：

#echo "Just pushing some text as original UFW input to make FAILURE" > $expected_output_file

2 个相等的字符串（预期状态和当前状态）评估为 false

2 equal strings (expected status and current status) evaluate to false

string

bash

output

verify

ufw