Basic knowledge of Linux learning (vi)

1. Copy the/etc/rc.d/rc.sysinit file to the/tmp directory and add # to the beginning of the line with at least one whitespace character in the/tmp/rc.sysinit file;

cp/etc/rc.d/rc.sysinit/tmp/

Vim/tmp/rc.sysinit

:%s/^[[:space:]]/#&/

:%s/\ (^ \)/#/g

match format: s/What to look for/what to replace/g global

2, copy/boot/grub/grub.conf to/tmp directory, delete the blank character of the beginning of the/tmp/grub.conf file;

cp/boot/grub/grub.conf/tmp/

Vi/tmp/grub.conf

:%s/^[[:space:]]\+// This will match the blank characters at the beginning of the line, the beginning of the line can be dead any white space characters;

:%s/^[[:space:]]//g This expression will remove the first whitespace character from the beginning of the line;

3. Remove the # and white space characters from the/tmp/rc.sysinit file that begin with # and followed by at least one white-space character

Vi/tmp/rc.sysinit

:%s/^#[[:space:]]\+//g

4. Add # to the beginning of the first three lines in the/tmp/grub.conf file;

Vi/tmp/grub.conf

: 1,3s/^/#/

5. Change the last 0 of all enabled=0 or gpgcheck=0 in the/etc/yum.repos.d/centos-media.repo file to 1;

Vi/etc/yum.repos.d/c

:%s/enabled=0/enabled=1/g

:%s/gpgcheck=0/gpgcheck=1/g

6, every 4 hours to perform a backup of the/etc directory, back up to the/backup directory, save the directory named Shape etc-201608300202

Crontab-e

XX */4 * * * root/bin/tar-cjf/backup/etc-' date +%y%m%d%h%m '/etc

Scheduled tasks: Time-sharing week

7, weekly 2,4,6 backup/var/log/messages file to/backup/messages_logs/directory, save the file name like messages-20160830

Crontab-e

* * * 2,4,6 root/bin/cp/var/log/messages/backup/messages_logs/messages-' date +%y%m%d '. bak

8, every two hours every day to take the current system/proc/meminfo file in the beginning of all the information in the S./stats/memory.txt file

Crontab-e

XX */2 * * * cat/proc/meminfo | grep "^s*" >>/stats/memory/txt

9, working days of work time, every two hours to perform the echo "Howdy"

Crontab-e

XX 9-18/2 * * 1-5/usr/bin/echo "Howdy"

Script Programming Exercises

10, create the directory/tmp/testdir-the current date and time;

11. Create 100 empty files in this directory: file1-file100

#/bin/bash

Export dirtime= ' Date +%y%m%d%h%m '

mkdir/tmp/testdir-$dirtime

For f in {1..100};d o

touch/tmp/testdir-$dirtime/file$f

Done

12. Display the user name of the user who is located in the/etc/passwd file in the first even row;

#/bin/bash

Awk-f: ' nr%2==0 {print$1} '/etc/passwd

13. Create 10 user user10-user19, password and user name;

14, create 10 empty files file10-file19 in/tmp/;

15. Change the file10 and the genus to user10, and so on.

#/bin/bash

For I in {10..19};do

If ID user$i &>/dev/null;then

echo "User is Exit"

Else

Useradd user$i && echo "User$i" | passwd--sdin user$i &>/dev/null

Fi

Touch/tmp/file$i

Chown user$i:user$i/tmp/fule$i

Done

Basic knowledge of Linux learning (vi)