Linux Practical Case-1

1, the creation of a 10G file system, the type of EXT4, requires the boot can be automatically mounted to a separate data/data directory;

[[email protected] ~]# dd If=/dev/zero of=/root/test bs=10m count=1000

Recorded 1000+0 read-in

Recorded the writing of 1000+0.

10485760000 gigabytes (GB) replicated, 13.7358 sec, 763 MB/s

[Email protected] ~]# losetup/dev/loop0/root/test

[Email protected] ~]# mkfs.ext4-l mydata/dev/loop0

MKE2FS 1.42.9 (28-dec-2013)

Discarding device blocks: complete

File System label =mydata

OS Type:linux

Block size =4096 (log=2)

Chunked size =4096 (log=2)

Stride=0 blocks, Stripe width=0 blocks

640848 inodes, 2560000 blocks

128000 blocks (5.00%) reserved for the Super user

First block of data =0

Maximum filesystem blocks=2151677952

Block groups

32768 blocks per group, 32768 fragments per group

8112 inodes per group

Superblock backups stored on blocks:

32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632

Allocating group tables: complete

Writing Inode table: complete

Creating Journal (32768 blocks): complete

Writing Superblocks and FileSystem accounting information: Complete

[Email protected] ~]# Vim/etc/fstab

-bash:vim: Command not found

[Email protected] ~]# Vi/etc/fstab

#

#/etc/fstab

# Created by Anaconda on Sat 12 16:40:22 2015

#

# Accessible filesystems, by reference, is maintained under '/dev/disk '

# See mans Pages Fstab (5), Findfs (8), mount (8) and/or Blkid (8) for more info

#

/DEV/MAPPER/CENTOS-ROOT/XFS Defaults 0 0

Uuid=a75083b6-f119-487d-a023-3f98dcfd438a/boot XFS Defaults 0 0

/dev/mapper/centos-swap swap swap defaults 0 0

Label= ' MyData '/data ext4 defaults 0 0

2, display the ' Netstat-tan ' command results with ' LISTEN ' followed by 0, one or more blank characters end of the line;

Centos7 need to install Net-tools to use Netstat tool

Yum Install Net-tools

[Email protected] ~]# Netstat-tan | grep "LISTEN *$"

TCP 0 0 0.0.0.0:22 0.0.0.0:* LISTEN

TCP 0 0 127.0.0.1:25 0.0.0.0:* LISTEN

TCP6 0 0::: $:::* LISTEN

TCP6 0 0:: 1:25:::* LISTEN

[Email protected] ~]#

3, add user Nginx, Zabbix, Tomcat, Nologin and Hadoop users (nologin user's shell is/sbin/nologin), and then find the/etc/passwd file in the same user name and shell name of the row;

[Email protected] ~]#

[Email protected] ~]# Useradd nginx

[Email protected] ~]# Useradd Zabbix

[Email protected] ~]# Useradd Tomcat

[Email protected] ~]# Useradd Hadoop

[Email protected] ~]# useradd nologin-s/sbin/nologin

[Email protected] ~]# CAT/ETC/PASSWD | grep "^\ (. *\):. */\1$"

Sync:x:5:0:sync:/sbin:/bin/sync

Shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown

Halt:x:7:0:halt:/sbin:/sbin/halt

Nologin:x:1005:1005::/home/nologin:/sbin/nologin

[Email protected] ~]#

4, find a word in the/etc/rc.d/init.d/functions file (the middle of the word can be underlined) followed by a set of parentheses line;

[Email protected] ~]# Cat/etc/rc.d/init.d/functions | grep "[A-Z | _]()"

Systemctl_redirect () {

Checkpid () {

__pids_var_run () {

__pids_pidof () {

Daemon () {

Killproc () {

Pidfileofproc () {

Pidofproc () {

Status () {

Echo_success () {

Echo_failure () {

Echo_passed () {

Echo_warning () {

Update_boot_stage () {

Success () {

Failure () {

Passed () {

Warning () {

Action () {

Strstr () {

Is_ignored_file () {

Is_true () {

Is_false () {

Apply_sysctl () {

[Email protected] ~]#

5, use echo to output a path, and then egrep find its path base name; Further use Egrep to remove its directory name (note that the directory name, not the directory path);

[Email protected] ~]# echo "/etc/text" | Egrep-o "[^/]*$"

Text

[Email protected] ~]# echo "/etc/text" | Egrep-o ". * *" | Egrep-o ". *[^/]"

/etc

[Email protected] ~]#

6. Find all files that are not root, bin or hadoop under the/usr directory;

[Email protected] ~]#

[Email protected] ~]# find/usr-not \ (-user root-o-user bin-o-user hadoop \)-ls

210602 0 drwx------2 polkitd root 6 June 2014/USR/SHARE/POLKIT-1/RULES.D

[Email protected] ~]#

7, one day the system was invaded, hackers in your system to leave the Trojan file:

You now need to find all the files on the current system that are not owned by the master or group and have been visited in the last week;

In addition, it is necessary to find all files of more than 20k and type ordinary files in/etc directory;

[Email protected] ~]# Clear

[[email protected] ~]# Find/-atime-7-nouser-o-nogroup

Find: '/PROC/2590/TASK/2590/FD/6 ': no file or directory

Find: '/PROC/2590/TASK/2590/FDINFO/6 ': no file or directory

Find: '/PROC/2590/FD/6 ': no file or directory

Find: '/PROC/2590/FDINFO/6 ': no file or directory

[Email protected] ~]# Find/etc-type f-size +20k

Find: Invalid-size type "K"

[Email protected] ~]# Find/etc-type f-size +20k

/etc/pki/ca-trust/extracted/java/cacerts

/etc/pki/ca-trust/extracted/openssl/ca-bundle.trust.crt

/etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem

/etc/pki/ca-trust/extracted/pem/email-ca-bundle.pem

/etc/pki/ca-trust/extracted/pem/objsign-ca-bundle.pem

/etc/pki/nssdb/cert8.db

/etc/udev/hwdb.bin

/etc/services

/etc/sysconfig/network-scripts/network-functions-ipv6

/etc/ssh/moduli

/etc/dnsmasq.conf

/etc/lvm/lvm.conf

/etc/selinux/targeted/contexts/files/file_contexts

/etc/selinux/targeted/modules/active/base.pp

/etc/selinux/targeted/modules/active/file_contexts

/etc/selinux/targeted/modules/active/file_contexts.template

/etc/selinux/targeted/modules/active/modules/apache.pp

/etc/selinux/targeted/modules/active/modules/init.pp

/etc/selinux/targeted/modules/active/modules/staff.pp

/etc/selinux/targeted/modules/active/modules/sysadm.pp

/etc/selinux/targeted/modules/active/modules/unprivuser.pp

/etc/selinux/targeted/modules/active/modules/virt.pp

/etc/selinux/targeted/modules/active/modules/xguest.pp

/etc/selinux/targeted/modules/active/modules/xserver.pp

/etc/selinux/targeted/policy/policy.29

/etc/openldap/certs/cert8.db

/etc/postfix/access

/etc/postfix/header_checks

/etc/postfix/main.cf

[Email protected] ~]#

8, create the directory/test/data, let a group of ordinary users have write permissions to it, and all the files created by the group is the directory belongs to the group; In addition, each user can only delete their own files.

Mkdir-p/test/data

Chmod-r 1774/test/data

This article from the "Smart Young Planck" blog, declined to reprint!

Linux Practical Case-1