这是我的run.bash文件（如果我删除$line = ...，我无法完全迭代该文件）：

#!/usr/bin/bash

while IFS= read -r line
do
    if [ "$(ssh -p2200 "$line" "sha256sum /home/config.conf | awk '{print $1}'")" == "$(ssh -p2200 "$line" "sha256sum /home/config.conf-bk | awk '{print $1}'")" ]
    then
        echo "File is the same in \"$line\"." > /dev/null 2>&1 # this output is not important
    else
        echo "The config.conf file in $line has changed, so we reverted the file." | mail -s "The config.conf file in $line has changed" myemail@gmail.com
        ssh -np2200 "$line" cp -a /home/config.conf-bk /home/config.conf
    fi
done < file.txt

字符串
这是file.txt：

G9DG1.fqdn.com
G9DG2.fqdn.com
G9DG3.fqdn.com
G9DG4.fqdn.com
G9DC3.fqdn.com
G9DG5.fqdn.com
G9DC4.fqdn.com

型
这是/home/config.conf和/home/config.conf-bk，它们在每台服务器上都应该相同：

# this is a test config file

型
这是sha256sum config.conf：

91c17dcc7bc4c48594c0d8eb9726b97e5e2c6aaf728779c9e39a69fe76229c9e  config.conf

型
此时，sha256sum这个文件的值与config.conf-bk文件相同。现在，如果我运行脚本，它会打印：

The config.conf file in G9DG1.fqdn.com has changed, so we reverted the file

型
我也把我的剧本改成：

#!/usr/bin/bash

while IFS= read -r line
do
    if [[ "$line" =~ ^([Gg][0-9]{1,2}[DS][C][0-9]{1,3}.fqdn.com)$ ]] # C-Plans
    then
        if [ "$(ssh -p2200 "$line" "sha256sum /home/config.conf | awk '{print $1}'")" == "$(ssh -p2200 "$line" "sha256sum /home/config.conf-bk | awk '{print $1}'")" ]
        then
            echo "File is the same in \"$line\"." > /dev/null 2>&1 # this output is not important
        else
            echo "The config.conf file in \"$line\" has changed, so we reverted the file." | mail -s "The config.conf file in \"$line\" has changed" myemail@gmail.com
            ssh -np2200 "$line" cp -a /home/config.conf-bk /home/config.conf
        fi
    elif [[ "$line" =~ ^([Gg][0-9]{1,2}[DS][G][0-9]{1,3}.fqdn.com)$ ]] # G-Plans
    then
        if [ "$(ssh -p2200 \"$line\" "sha256sum /home/config.conf | awk '{print $1}'")" == "$(ssh -p2200 \"$line\" "sha256sum /home/config.conf-bk | awk '{print $1}'")" ]
        then
            echo "File is the same in $line." > /dev/null 2>&1 # this output is not important
        else
            echo "The config.conf file in $line has changed, so we reverted the file." | mail -s "The config.conf file in $line has changed" myemail@gmail.com
            ssh -np2200 "$line" cp -a /home/config.conf-bk /home/config.conf
        fi
    fi
done < file.txt

型
但这一次我明白了：

File is the same in G9DG1.fqdn.com.
File is the same in G9DG2.fqdn.com.
File is the same in G9DG3.fqdn.com.
File is the same in G9DG4.fqdn.com.
The config.conf file in G9DC3.fqdn.com has changed, so we reverted the file.

型
预期的输出是检查所有服务器（不仅在第一次匹配if和terminate子句之后），检查文件是否更改，然后执行if-else子句。

更新1

下面的bash文件现在在整个文件中循环，但始终回显两个内部循环的else部分：

#!/usr/bin/bash

while IFS= read -r line
do
    if [[ "$line" =~ ^([Gg][0-9]{1,2}[DS][C][0-9]{1,3}.fqdn.com)$ ]] # C-Plans
    then
        if [ "$(ssh -np2200 $line "sha256sum /home/config.conf | awk '{print $1}'")" == "$(ssh -np2200 $line "sha256sum /home/config.conf-bk | awk '{print $1}'")" ]
        then
            echo "It is the same in $line."
        else
            echo "The config.conf file in $line has changed, so we reverted the file."
        fi
    elif [[ "$line" =~ ^([Gg][0-9]{1,2}[DS][G][0-9]{1,3}.fqdn.com)$ ]] # G-Plans
    then
        if [ "$(ssh -np2200 $line "sha256sum /home/config.conf | awk '{print $1}'")" == "$(ssh -np2200 $line "sha256sum /home/config.conf-bk | awk '{print $1}'")" ]
        then
            echo "It is the same in $line."
        else
            echo "The config.conf file in $line has changed, so we reverted the file."
        fi
    fi
done < file.txt

型
当前（意外）输出：

It is not the same in G1DG1.fqdn.com.
It is not the same in G1DG2.fqdn.com.
It is not the same in G1DG3.fqdn.com.
It is not the same in G1DG4.fqdn.com.
It is not the same in G1DC3.fqdn.com.
It is not the same in G1DG5.fqdn.com.
It is not the same in G1DC4.fqdn.com.

型