如何从文件读取字符串并与第二个文件的每一行进行比较

2024-5-22 • tag-icon

我正在制作操作系统安装后脚本，其中将包括强化部分。在这个强化部分中，它将从文件 A 中读取内核参数并与文件 /etc/sysctl.conf 进行比较，如果参数在 sysctl.conf 中不可用，那么它将把它添加到 sysctl.conf 中。

自定义文件中的参数

################## Hardening ############################

kernel.exec-shield = 1
kernel.randomize_va_space = 1
net.ipv4.icmp_echo_ignore_broadcasts = 1
net.ipv4.icmp_ignore_bogus_error_responses = 1
net.ipv4.tcp_syncookies = 1
net.ipv4.conf.all.log_martians = 1
net.ipv4.conf.all.accept_redirects = 0
net.ipv4.conf.all.rp_filter = 1
net.ipv4.conf.all.send_redirects = 0
net.ipv4.conf.default.accept_redirects = 0
net.ipv4.conf.default.log_martians = 1
net.ipv4.tcp_timestamps = 0
net.ipv6.conf.all.accept_redirects = 0
net.ipv6.conf.default.accept_redirects = 0

##########################################################

现在我添加了这些行以进行强化。

for i in $(cat /etc/sysctl.conf)
do
        if ! grep -Fxq " $i " /etc/sysctl.conf
        then
        echo -e "$i" > ~/testfile
        fi
done

这个脚本的问题在于它将内核参数中的每个空格视为空格行，并且问题从“for i in $(cat /etc/sysctl.conf)”的开头开始

这是调试信息

./LinuxHardening.sh
++ date
+ LOGDATE='Mon Feb  9 07:58:07 EST 2015'
+ echo Mon Feb 9 07:58:07 EST 2015
+ tee HardeningLog
Mon Feb 9 07:58:07 EST 2015
+ echo -e '\n############ Kernel Hardening ############'
+ tee -a HardeningLog

############ Kernel Hardening ############
++ cat kernelparms
+ for i in '$(cat kernelparms)'
+ grep -Fxq '##################' /etc/sysctl.conf
+ echo -e '##################'
+ for i in '$(cat kernelparms)'
+ grep -Fxq Hardening /etc/sysctl.conf
+ echo -e Hardening
+ for i in '$(cat kernelparms)'
+ grep -Fxq '############################' /etc/sysctl.conf
+ echo -e '############################'
+ for i in '$(cat kernelparms)'
+ grep -Fxq kernel.exec-shield /etc/sysctl.conf
+ echo -e kernel.exec-shield
+ for i in '$(cat kernelparms)'
+ grep -Fxq = /etc/sysctl.conf
+ echo -e =
+ for i in '$(cat kernelparms)'
+ grep -Fxq 1 /etc/sysctl.conf
+ echo -e 1
+ for i in '$(cat kernelparms)'
+ grep -Fxq kernel.randomize_va_space /etc/sysctl.conf
+ echo -e kernel.randomize_va_space
+ for i in '$(cat kernelparms)'
+ grep -Fxq = /etc/sysctl.conf
+ echo -e =
+ for i in '$(cat kernelparms)'
+ grep -Fxq 1 /etc/sysctl.conf
+ echo -e 1
+ for i in '$(cat kernelparms)'
+ grep -Fxq net.ipv4.icmp_echo_ignore_broadcasts /etc/sysctl.conf
+ echo -e net.ipv4.icmp_echo_ignore_broadcasts
+ for i in '$(cat kernelparms)'
+ grep -Fxq = /etc/sysctl.conf
+ echo -e =
+ for i in '$(cat kernelparms)'
+ grep -Fxq 1 /etc/sysctl.conf
+ echo -e 1
+ for i in '$(cat kernelparms)'
+ grep -Fxq net.ipv4.icmp_ignore_bogus_error_responses /etc/sysctl.conf
+ echo -e net.ipv4.icmp_ignore_bogus_error_responses
+ for i in '$(cat kernelparms)'
+ grep -Fxq = /etc/sysctl.conf
+ echo -e =
+ for i in '$(cat kernelparms)'
+ grep -Fxq 1 /etc/sysctl.conf
+ echo -e 1
+ for i in '$(cat kernelparms)'
+ grep -Fxq net.ipv4.tcp_syncookies /etc/sysctl.conf
+ echo -e net.ipv4.tcp_syncookies
+ for i in '$(cat kernelparms)'
+ grep -Fxq = /etc/sysctl.conf
+ echo -e =
+ for i in '$(cat kernelparms)'
+ grep -Fxq 1 /etc/sysctl.conf
+ echo -e 1
+ for i in '$(cat kernelparms)'
+ grep -Fxq net.ipv4.conf.all.log_martians /etc/sysctl.conf
+ echo -e net.ipv4.conf.all.log_martians
+ for i in '$(cat kernelparms)'
+ grep -Fxq = /etc/sysctl.conf
+ echo -e =
+ for i in '$(cat kernelparms)'
+ grep -Fxq 1 /etc/sysctl.conf
+ echo -e 1
+ for i in '$(cat kernelparms)'
+ grep -Fxq net.ipv4.conf.all.accept_redirects /etc/sysctl.conf
+ echo -e net.ipv4.conf.all.accept_redirects
+ for i in '$(cat kernelparms)'
+ grep -Fxq = /etc/sysctl.conf
+ echo -e =
+ for i in '$(cat kernelparms)'
+ grep -Fxq 0 /etc/sysctl.conf
+ echo -e 0
+ for i in '$(cat kernelparms)'
+ grep -Fxq net.ipv4.conf.all.rp_filter /etc/sysctl.conf
+ echo -e net.ipv4.conf.all.rp_filter
+ for i in '$(cat kernelparms)'
+ grep -Fxq = /etc/sysctl.conf
+ echo -e =
+ for i in '$(cat kernelparms)'
+ grep -Fxq 1 /etc/sysctl.conf
+ echo -e 1
+ for i in '$(cat kernelparms)'
+ grep -Fxq net.ipv4.conf.all.send_redirects /etc/sysctl.conf
+ echo -e net.ipv4.conf.all.send_redirects
+ for i in '$(cat kernelparms)'
+ grep -Fxq = /etc/sysctl.conf
+ echo -e =
+ for i in '$(cat kernelparms)'
+ grep -Fxq 0 /etc/sysctl.conf
+ echo -e 0
+ for i in '$(cat kernelparms)'
+ grep -Fxq net.ipv4.conf.default.accept_redirects /etc/sysctl.conf
+ echo -e net.ipv4.conf.default.accept_redirects
+ for i in '$(cat kernelparms)'
+ grep -Fxq = /etc/sysctl.conf
+ echo -e =
+ for i in '$(cat kernelparms)'
+ grep -Fxq 0 /etc/sysctl.conf
+ echo -e 0
+ for i in '$(cat kernelparms)'
+ grep -Fxq net.ipv4.conf.default.log_martians /etc/sysctl.conf
+ echo -e net.ipv4.conf.default.log_martians
+ for i in '$(cat kernelparms)'
+ grep -Fxq = /etc/sysctl.conf
+ echo -e =
+ for i in '$(cat kernelparms)'
+ grep -Fxq 1 /etc/sysctl.conf
+ echo -e 1
+ for i in '$(cat kernelparms)'
+ grep -Fxq net.ipv4.tcp_timestamps /etc/sysctl.conf
+ echo -e net.ipv4.tcp_timestamps
+ for i in '$(cat kernelparms)'
+ grep -Fxq = /etc/sysctl.conf
+ echo -e =
+ for i in '$(cat kernelparms)'
+ grep -Fxq 0 /etc/sysctl.conf
+ echo -e 0
+ for i in '$(cat kernelparms)'
+ grep -Fxq net.ipv6.conf.all.accept_redirects /etc/sysctl.conf
+ echo -e net.ipv6.conf.all.accept_redirects
+ for i in '$(cat kernelparms)'
+ grep -Fxq = /etc/sysctl.conf
+ echo -e =
+ for i in '$(cat kernelparms)'
+ grep -Fxq 0 /etc/sysctl.conf
+ echo -e 0
+ for i in '$(cat kernelparms)'
+ grep -Fxq net.ipv6.conf.default.accept_redirects /etc/sysctl.conf
+ echo -e net.ipv6.conf.default.accept_redirects
+ for i in '$(cat kernelparms)'
+ grep -Fxq = /etc/sysctl.conf
+ echo -e =
+ for i in '$(cat kernelparms)'
+ grep -Fxq 0 /etc/sysctl.conf
+ echo -e 0
+ for i in '$(cat kernelparms)'
+ grep -Fxq '##########################################################' /etc/sysctl.conf
+ echo -e '##########################################################'

答案1

为什么不使用 while 逐行读取：

while read -r line
do
        if ! grep -Fxq " $line " /etc/sysctl.conf
        then
        echo -e "$line" >> ~/testfile
        fi
done </etc/sysctl.conf

并将 > 替换为 >>。

答案2

尝试类似的方法：

while read i
do
        if ! grep -Fxq " $i " /etc/sysctl.conf
        then
        echo -e "$i" >> ~/testfile
        fi
done<kernelparms

答案3

与awk和关联数组:

awk '!/^($|#)/{arr[$1]=$0}END{for(param in arr) print arr[param]}' /etc/sysctl.conf custom.conf

如果顺序很重要：

awk '!/^($|#)/{
  arr[$1] = $0
}
END {
  for(key in arr)
    print arr[key]
}' /etc/sysctl.conf custom.conf | sort > hardened.conf

!/^($|#)/- 忽略注释行或空行
{arr[$1]=$0}- 将每一行存储到 arr 中，并将其与内核参数相关联；每次看到相同的参数（即从custom.conf最后一个要读取的文件）时，该行都会更新
END{for(param in arr) print arr[param]}- 读取所有输入后，打印每个内核参数的关联行。

答案4

设置IFS=$'\n'它不会将空格视为新行。

答案1

答案2

答案3

答案4

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