Sed job

1、 Delete /etc/grub2.conf All the white space characters at the beginning of the line that start with white space in the file

sed 's/^[[:space:]]//' /etc/grub2.conf

2、 Delete /etc/fstab All # start , The first line of a line followed by at least one white space character # And white space characters

sed 's/^#[[:space:]]*//g' /etc/fstab

3、 stay /root/install.log Add... At the beginning of each line # Number

sed 's/^.*$/#&/' /root/install.log

4、 stay /etc/fstab The document does not contain # The beginning of the first line increases # Number

sed 's/^[^#]/#&/' /root/install.log

5、 utilize sed Take out ifconfig In the command IPv4 Address

 ifconfig | sed -n 2p | sed -r "s/.*inet[[:space:]]*//" | sed -r "s/[[:space:]]*netmask.*//"

6、 Turn off the machine SELinux The function of

sed -i 's/SELINUX=enforcing/SELINUX=disabled/g' /etc/selinux/config

7、 stay /etc/hosts Add content to the configuration file

sed -i '1 i hhhh' hosts
sed -i '$ a heihei ' hosts