Linux the next day

A file Operation command

　　1) Create an empty file or modify the file time

Touch file name

Command name: Touch

Command path:/bin/touch

Execute Permissions: All Users

2) Delete

RM-RF file name

-R Delete Directory

-F Mandatory

Command name: RM

Command English original meaning: remove

Command path:/BIN/RM

Execute Permissions: All Users

3) Cat file name to view the contents of the file. From beginning to end

Command name: Cat

Command path:/bin/cat

Execute Permissions: All Users

- n list line numbers

4) More filename split screen display file contents

Command name: more

Command path:/bin/more

Execute Permissions: All Users

Space down page b page Up Q exit

5) Head filename Display file header

Command name: Head

Command path:/usr/bin/head

Execute Permissions: All Users

Head-n number of rows file name Specifies the first few lines to display

Head-n 20 file name

HEAD-20 file name

CTRL + C forced termination

Ctrl+l Clear Screen

6) linked files

ln

Command name: LN

Command English original meaning: link

Command path:/BIN/LN

Execute Permissions: All Users

Shortcut

New links that occupy different hard disk locations

Modify a file, both change

Delete source file, soft connection cannot open

Ln-s source File The file name must write absolute path

Two commands that both files and directories can manipulate

1) RM Delete file or directory

2) Copy

Command name: CP

Command English Original: copy

Command path:/BIN/CP

Execute Permissions: All Users

CP Source file target Location

-R Copy Directory

-P Joint file attribute copy

-D If the source file is a linked file, copy the link property

-A equals-pdr

CP aa/tmp/ formerly copied

CP aa/tmp/bb renamed copy

3) Cut or rename

Command name: MV

Command English Intent: move

Command path:/BIN/MV

Execute Permissions: All Users

MV Source File Destination location

mv/root/aa/tmp/

MV AA BB

Three Rights Management

1 Permission bits

-rw-r--r--1 root root 0 08-11 01:45 AA

The permission bit is 10 bits

First bit: represents the file type

- Normal file

d Catalog File

L Link File

Nine-bit Master permission u group permissions g other person permissions o

R- Read 4

W Write 2

x execution 1

2 Modify Permissions

chmod

Command name: chmod

Command English Original: Change the permissions mode of a file

Command path:/bin/chmod

Execute Permissions: All Users

chmod u+x aa AA file owner plus execute permission

chmod u-x AA

chmod g+w,o+w AA

chmod u=rwx AA

chmod 755 AA

chmod 644 AA

3 Permission meanings:

1) permissions on the meaning of the file

R: Read file contents cat more head tail

W: Edit, add, modify file contents VI echo

But does not contain delete files

X: Executable

2) permissions on the meaning of the directory

R: Can query the directory under the file name ls

W: has permission to modify the directory structure. such as creating new files and directories, deleting files and directories under this directory, renaming files and directories under this directory, cutting touch RM mv CP

X: Access to the catalog CD

4 generic and group commands

Chown

Command name: Chown

Command English Original: Change file ownership

Command path:/bin/chown

Execute Permissions: All Users

Chown user name filename Change file owner

Chown user1 AA user1 must exist

Chown user1:user1 aa change Genus Master simultaneous change group

Useradd User name Add user

passwd User name set user password

Four help Commands

1 man command name Help for viewing commands

Command name: Man

Command English original meaning: manual

Command path:/usr/bin/man

Execute Permissions: All Users

2 command--help Common options for viewing commands

Five Find command

1 whereis command name to find commands for command, see also help document location

Command name: Whereis

Command path:/usr/bin/whereis

Execute Permissions: All Users

2 Find search command

Command name: Find

Command path:/usr/bin/find

Execute Permissions: All Users

Find by file name

Find Find location-name file name

Find/-name aabbcc by file name

by user

-user user name to find files according to the master user name

-group group names find files by group name

-nouser to find documents that are not owned by the Lord

/proc

/sys

/mnt/cdrom/ In addition to these three directories

Find/-nouser

Follow file permissions

-name by file name

-size by file size k M

Find/-size +50k

-type type Find by file type F: normal D: directory L: Link

Find/root-perm 644 Search by Permissions

-iname Search by file name, case insensitive

3 grep "string" file name finds the word serial that matches the criteria.

Command name: grep

Command path:/bin/grep

Execute Permissions: All Users

Grep-i "Root"/etc/passwd

-V Reverse selection

-I ignores case

4 Pipe Break

Command 1 | Command 2 execution result of command 1, as the execution condition of command 2

Cat file name | grep "string" extracts a line containing a string

grep "string" file name

Ls-l/etc | More split screen display ls content

Six compression and decompression

. gz . bz2 Common compression formats that can be recognized by Linux

. tar.gz . tar.bz2 Common compression and packaging commands

Compress and package at the same time

TAR-ZCVF Compressed file name source file

TAR-ZCVF aa.tar.gz AA

-Z recognition. gz format

-C: compression

-V: Show compression process

-F: Specify the name of the compressed package

TAR-ZXVF Compressed file name decompression and unpacking

TAR-JCVF Compressed file name source file compression at the same time package

TAR-JCVF aa.tar.bz2 AA

TAR-JXVF AA.TAR.BZ2 Solution Package Simultaneous decompression

View Puzzle Package

TAR-ZTVF aa.tar.gz View Puzzle

TAR-JTVF aa.tar.bz2

-T only view, no pressure

TAR-JXVF root.tar.bz2-c/tmp/ Specify the decompression position

Seven shutdown and restart commands

1) shutdown-h now No special case, use this command

-H shutdown

- R restart

Shutdown-r now

Command name: Shutdown

Command path:/sbin/shutdown

Execute permissions: Root

2) reboot

Command name: Reboot

Command path:/sbin/reboot

Execute permissions: Root

Eight- mount command

All Linux storage devices must be mounted for use, including hard drives

Command name: Mount

Command path:/bin/mount

Execute Permissions: All Users

CD mount

/DEV/SDA1 first partition of the first SCSI hard drive

/dev/cdrom Disc

/DEV/HDC IDE Hard drive CentOS 5.5

/dev/sr0 CD CentOS 6.x

MOUNT-T File System Device description file mount point (empty directory already exists)

Mount-t Iso9660/dev/cdrom/mnt/cdrom

CD Uninstall

Umount/dev/cdrom

Umount/mnt/cdrom : Exit the Mount directory before uninstalling

Fdisk-l

Mount-t Vfat/dev/sdb1/mnt/usb

NineNetwork Commands

1 ping Test network connectivity

Command name: Ping

Command path:/bin/ping

Execute Permissions: All Users

ping-c frequency IP detection network unobstructed

2 ifconfig query native network information

Command name: ifconfig

Command English original meaning: interface configure

Command path:/sbin/ifconfig

Execute permissions: Root

Linux the next day