Two small shell scripts

Prevent other people from brute force password and deny this IP access to SSH service if someone tries to enter a password error number 5 times.

#!/bin/bashlastb | awk  ' {print $3} '  | uniq -c | sort -r  > a.txtsed -ri  ' [email protected]^[[:space:]][email protected]@g '   a.txtsed -ri  ' [email protected][[:space:]][email protected][email protected] '   a.txtb=$ (cat a.txt) for i in  $bdo   ip= ' echo  $i  | awk -f=   ' {print $2} '   cishu= ' echo  $i  | awk -F=  ' {print $1} '    if [  $cishu  -ge 5 ];then     grep  "$ip"  /etc /hosts.deny &> /dev/null      if [ $? != 0  ];then        echo  "sshd: $ip"  >> /etc/ hosts.deny        echo sed -i  '/192.168.0.101$/d '   /etc/hosts.deny | at&nbSp;12am +7 day >> /dev/null      fi  fidone 

#!/bin/bashservices= ' chkconfig  --list | grep -e  ' 3: (on| enabled) "| awk    ' {print $1} '  | grep -vE  ' Crond|network|sshd|syslog ' touch /tmp/ services.txtfor i in  $servicesdo   chkconfig  $i  off  echo  " Disable System Services $i "  echo  $i  >> /tmp/services.txtdonehang= ' wc -l /tmp/ services.txt | awk  ' {print $1} ' if [  $hang  -lt 1 ];then   echo  "Current system service is optimized" firm -f /tmp/services.txt# Delete system redundancy account Username= ' grep -e  "news| Uucp|games|gopher " /etc/passwd | awk -F:  ' {print $1} ' for i in $ usernamedo  userdel -r  $i  &> /dev/null  echo  "deleted redundant account $i" done# ensure that the user's login shell has not been altered denglu= ' grep  '/bin/bash '  /etc/passwd | awk -F:  ' {print  $1} ' renshu= ' grep  "/bin/bash"  /eTc/passwd | wc -l ' echo  ' total $renshu users can log in to the system for i in  $dengludo    echo  "$i can log on to the system" done# set password validity period read -p  "Set password validity period (days):"  youxiaoqigrep -v pass_max_days  /etc/login.defs > /tmp/tmpecho  "pass_max_days      $youxiaoqi"  >> /tmp/tmpcp /tmp/tmp /etc/login.defsecho  "Set password is valid for $youxiaoqi days" #优化历史命令条目read  -p  Record History Command Entry (BAR): " lishigrep " histsize= " /etc/profile >> /dev/nullif  [ $? != 0 ];thenecho  "Histsize= $lishi"  >> /dev/nullelsesed  -ri s#histsize=.* #HISTSIZE = $lishi #g /etc/profile >> /dev/null figrep   "Clear"  /root/.bash_logout >> /dev/null    if [ $?  != 0 ];then         echo clear >>  /root/.bash_logout     fi   echo  "Empty history command when root user exits bash" was successfully set #优化闲置超时时间的read  -p    Idle Time-out (minutes): " sjgrep " Export tmout " /etc/profile &> /dev/ nullif [ $? != 0 ];then  echo  "export tmout= $sj"  >>  /etc/profileelse  sed -ri s# "export tmout=.*" # "export tmout= $sj" #g  / etc/profile &> /dev/nullfi# Disable Ctrl+alt+del Hotkey restart grep  "#ca::"  /etc/inittab > > /dev/nullif [ $? != 0 ];then   sed -ri [email  protected]::@ #ca:: @g /etc/inittab >> /dev/null     if  [ $? = 0 ];then       echo  "banned the ctrl+alt+ Del hotkey Restart "     else       echo " Disable ctrl+alt+ Del Hotkey Restart failed, please manually set "     fi   else   echo  "Previously banned Ctrl+alt+del hotkey restart, no longer set here" fi# Set GRUB encryption password grep  Password /boot/grub/grub.conf &> /dev/nullif [ $? = 0 ];then    sed -ri  '/^password/d '  /boot/grub/grub.conf &> /dev/nullfi    read -p  "Set GRUB encryption Password:"  md5m   md5miyao= ' echo -e  "$ md5m\n$md5m " | /sbin/grub-md5-crypt 2> /dev/null | tail -1 '     sed  -ri  '/^title/i\password --md5   ' $md 5miyao '  /boot/grub/grub.conf  &> /dev/null# Modify login Prompt read -p  "Please enter login prompt"  tishiecho  $tishi  >  /etc/issue# reduce the number of open TTY terminals for i in {2..6}do grep  "\# $i: 2345"  /etc/inittab  >> /dev/null if [ $? != 0 ];then    sed  -ri [email protecTed] $i: [email protected]# $i:[email protected] /etc/inittab >> /dev/null     echo  "closed tty$i Terminal"  fidone# file descriptor read -p  "set file descriptor (recommended setting range 30,000 to 60,000):"   miaoshufuulimit -hsn  $miaoshufuecho   "*           -            nofile           $miaoshufu " >> /etc/security/limits.conf

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Two small shell scripts