1. 用shell實(shí)現(xiàn)傳入進(jìn)程pid征炼， 查看對(duì)應(yīng)進(jìn)程/proc下CPU酸些、內(nèi)存指標(biāo)

1.編寫(xiě)腳本

[root@centos7 bin]vim proInfo.sh
while true;do
    read -p "Please input a pid or quit:" pid
    if [ -z $pid ];then
        continue
    elif [[ $pid =~ ^[Qq]$|^[Qq][Uu][Ii][Tt]$ ]];then
         exit 0
    elif [[ ! $pid =~ ^[1-9][0-9]*$ ]];then
        echo -e "\e[1;31mYour input is error\e[0m"
        continue
    else
        result=`ps axo pid,comm,%cpu,%mem | grep $pid`
        if [ $? -eq 0 ];then
            echo $result | awk 'BEGIN{print "pid\tcomm\t%cpu\t%mem"}{print $1"\t"$2"\t"$3"\t"$4}'
        fi
    fi
done

2.測(cè)試腳本

[root@centos7 bin]proInfo.sh 
Please input a pid or quit:ss
Your input is error
Please input a pid or quit:02
Your input is error
Please input a pid or quit:7
pid comm    %cpu    %mem
7   migration/0 0.0 0.0
Please input a pid or quit:1785
pid comm    %cpu    %mem
1785    sshd    0.0 0.1
Please input a pid or quit:q

2市栗、 編寫(xiě)Nginx的systemd配置文件盲赊， 實(shí)現(xiàn)nginx進(jìn)程開(kāi)機(jī)啟動(dòng)

待完善...

3、 用awk實(shí)現(xiàn)查看TCP的連接狀態(tài)

[root@centos7 bin]netstat -tan | awk '/^tcp/{state[$NF]++}END {for(i in state) { print i,state[i]}}'
ESTABLISHED 2
LISTEN 14

4缀台、 說(shuō)明對(duì)稱棠赛、非對(duì)稱加密算法的區(qū)別， 并舉例

1.用對(duì)稱加密加密文件

[root@centos7 ~]cp /etc/fstab .
[root@centos7 ~]gpg -c fstab
此時(shí)會(huì)跳出輸入密碼的對(duì)話框祠锣，這邊我輸入密碼為abc。如下圖所示

對(duì)稱加密.png

[root@centos7 ~]ls
······
fstab  fstab.gpg
將加密文件fstab.gpg發(fā)送給hostB解密
[root@centos7 ~]scp fstab.gpg 192.168.48.128:/root

在hostB上解密即可
[root@centos6 ~]gpg -o fstab -d fstab.gpg

解密.png

2.用非對(duì)稱加密加密文件

hostA生成秘鑰對(duì)
[root@centos7 ~]gpg --gen-key
這里不再顯示詳細(xì)的配置咽安，在最后的時(shí)候會(huì)有一個(gè)是否將私鑰加密的對(duì)話框伴网，可以選擇取消，這里我不取消板乙，輸入密碼是偷。如下圖所示

將私鑰加密.png

在hostA主機(jī)上查看公鑰
[root@centos7 ~]gpg --list-keys
/root/.gnupg/pubring.gpg
------------------------
pub   2048R/A7D0420C 2019-03-13
uid                  xiaoming <xxx@xxx.com>
sub   2048R/F00B5FAB 2019-03-13

導(dǎo)出hostA公鑰
[root@centos7 ~]gpg -a --export -o xiaoming.pubkey

將hostA的公鑰發(fā)送非hostB
[root@centos7 ~]scp xiaoming.pubkey 192.168.48.128:/root

hostB導(dǎo)入hostA的公鑰
[root@centos6 ~]gpg --import xiaoming.pubkey

用從hostA主機(jī)導(dǎo)入的公鑰，加密hostB主機(jī)的文件fstab,生成fstab.gpg
[root@centos6 ~]gpg -e -r xiaoming fstab

復(fù)制加密文件fstab.gpg到hostA主機(jī)
[root@centos6 ~]scp fstab.gpg 192.168.48.129:/root

在hostA主機(jī)解密文件募逞，先輸入私鑰密碼后即可解密
[root@centos7 ~] gpg -o fstab -d fstab.gpg

輸入私鑰密碼.png

注意
時(shí)區(qū)一定要同步蛋铆，同步時(shí)區(qū)命令：ntpdate cn.pool.ntp.org

5、 用shell實(shí)現(xiàn)修改/etc/sysctl.conf文件中的參數(shù)并生效

1.編寫(xiě)腳本

trap '' 2
while true;do
    read -p "Please enter kernel parameter or quit:" param
    if [ -z $param ];then
        continue
    elif [[ $param =~ ^[Qq]$|^[Qq][Uu][Ii][Tt]$ ]];then
        sysctl -p
        exit 0
    else
        sysctl $param &> /dev/null
        if [ $? -ne 0 ];then
            echo -e "\e[1;31mParameter does not exist\e[0m"
            continue
        else 
            read -p "Please enter a value:" val
            param2=${param//\./\\.}
            sed -ri "/^(${param2})/d" /etc/sysctl.conf
            setup=$param=$val
            echo $setup  >> /etc/sysctl.conf
            echo -e "\e[1;32mSet OK\e[0m"
        fi
    fi
done

2.測(cè)試腳本

[root@centos7 bin]setKernelPara.sh 
Please enter kernel parameter or quit:ss
Parameter does not exist
Please enter kernel parameter or quit:vm.vfs_cache_pressure
Please enter a value:100
Set OK
Please enter kernel parameter or quit:vm.user_reserve_kbytes
Please enter a value:31941
Set OK
Please enter kernel parameter or quit:q   
vm.vfs_cache_pressure = 100
vm.user_reserve_kbytes = 31941
[root@centos7 bin]cat /etc/sysctl.conf
···
vm.vfs_cache_pressure=100
vm.user_reserve_kbytes=31941

3.腳本存在的bug

[root@centos7 bin]setKernelPara.sh 
Please enter kernel parameter or quit:vm.vfs_cache_pressure
Please enter a value:s
Set OK
Please enter kernel parameter or quit:vm.user_reserve_kbytes
Please enter a value:
Set OK
Please enter kernel parameter or quit:quit
sysctl: setting key "vm.vfs_cache_pressure": Invalid argument
vm.vfs_cache_pressure = s
sysctl: /etc/sysctl.conf(12): invalid syntax, continuing...
[root@centos7 bin]cat /etc/sysctl.conf
···
vm.vfs_cache_pressure=s
vm.user_reserve_kbytes=

如果內(nèi)核參數(shù)傳入錯(cuò)誤的值放接，依然會(huì)提示ok且寫(xiě)入文件刺啦，暫時(shí)還沒(méi)想到好的解決方法。不過(guò)正常情況下不會(huì)沒(méi)事去輸個(gè)錯(cuò)誤的值纠脾，除非手誤玛瘸。如果確實(shí)錯(cuò)了，那么再次執(zhí)行腳本苟蹈，輸入正確參數(shù)即可糊渊，腳本會(huì)自動(dòng)將文件中原有的參數(shù)設(shè)置替換為新的

4.再次運(yùn)行腳本,修改錯(cuò)誤的參數(shù)值

[root@centos7 bin]setKernelPara.sh 
Please enter kernel parameter or quit:vm.vfs_cache_pressure
Please enter a value:100
Set OK
Please enter kernel parameter or quit:vm.user_reserve_kbytes
Please enter a value:31492
Set OK
Please enter kernel parameter or quit:quit
vm.vfs_cache_pressure = 100
vm.user_reserve_kbytes = 31492
[root@centos7 bin]cat /etc/sysctl.conf
···
vm.vfs_cache_pressure=100
vm.user_reserve_kbytes=31942