linux小技巧

1、md5sum检测文件变化

2、 grub加密及破解

 

 

md5sum检测文件变化
# md5sum /etc/passwd > /tmp/md5passwd
# md5sum -c /tmp/md5passwd
/etc/passwd: OK
# useradd test
# md5sum -c /tmp/md5passwd
/etc/passwd: FAILED
md5sum: WARNING: 1 of 1 computed checksum did NOT match

 

grub加密及破解（遗忘root密码只需进单用户模式更改即可）
生成加密密码
# grub-md5-crypt 
Password: 
Retype password: 
$1$ijJgG/$UzCPEaI3hVJaCNg4rAWS11
将密码文件加到/etc/grub.conf
password --md5 $1$ijJgG/$UzCPEaI3hVJaCNg4rAWS11
title CentOS 6 (2.6.32-573.el6.x86_64)

破解需要用rescure
bash-4.1#chroot /mnt/sysimage
sh-4.1#vi /etc/grub.conf    去除密文
sh-4.1#exit
bash-4.1#reboot