Linux command line

Linux First principle: must first back up the files to be modified

2012-05-24 (learning)

Recent books and the chaos, mainly to prepare, delete files, systems, sub-district of the related problems:

DD IF=/DEV/SDX OF=/DEV/SDX #將分區x完全複製到X

(Tip: DD is a copy of the block, so the time it takes to determine the size of the subregion, rather than the number of numbers in the subregion.)

The normal rate of copying is 30~60m/sec. 1G usually takes about 30 seconds)

The function of the CP command is to copy the given file or directory to another file or directory, which is very powerful.

Syntax: CP [option] source file or directory destination file or directory

Note: This command copies the specified source files to the destination file or copies multiple source files to the destination directory.

The options for this command have the following meanings:

-A This option is typically used when copying a directory. As far as possible, the file status, permissions and other information are reproduced as original.

-Keep links when copying D.

-F If a destination already has a file with the same file name, it should be deleted before copying and not prompted.

-I and F options, in contrast, will prompt the user for confirmation before overwriting the target file. Answer y when the target file will be overwritten, is an interactive copy.

-P At this point, the CP will also copy the modified time and access rights to the new file in addition to the contents of the source file.

-R If the source file is a directory file, the CP will recursively replicate all subdirectories and files in that directory to the destination. The destination file must be a directory name at this time.

-L do not make copies, just link files.

To prevent users from inadvertently using the CP command to destroy another file, such as the user specified target file name already exists, with the CP command to copy the file, the file will be overwritten by the Xinyuan file. It is recommended that users use the I option when copying files using the CP command.

Example:
$ cp-i test1.c/usr/cpp/test2.c
This command copies the file test1.c to the/usr/cpp directory and renames it to test2.c.

If you do not want to rename it, you can use the following command:
$ CP test1.c/usr/cpp/

Copy all log files to the BAK subdirectory:
$ cp *.log Bak

2012-05-23 (learning),

Create and delete user command questions

sudo useradd kevin-m-d/home/kevind #建立新用戶kevin, compelling to create a home record under///Kevind

sudo passwd Kevin #為用戶kevin建立新的密碼

sudo userdel Kevin #刪除用戶kevin

sudo rm/home/kevind-r #強制刪除目錄kevinD #-R Please be cautious before use

View User Details

Finger Kevin #可以查看主機用戶資料, it's dangerous.

Lock and unlock your user

Passwd-l Kevin #鎖定用戶kevin

Passwd-u Kevin #解鎖用戶kevin

Switch to user identity as another user

Su-l Kevin #將當前用戶更換為kevin, this time prompted to enter the password (is Kevin's password), in the chmod is very convenient to set the file

User Identity editor that can execute sudo commands

sudo visudo #用於編輯/etc/sudoers

2012-05-20 (learning)

sudo apt-get install software name installation software command

sudo nautilus Open file (with root permission)

SU root switches to "root"

LS lists the current directory file (excluding hidden files)

Ls-a list current directory files (including hidden files)

Ls-l list the files in the current directory for more information

Cd.. Back to the top-level directory of the current directory

CD-Back to the same directory

CD ~ or CD back to the current user's host directory

mkdir directory name Create a directory

RmDir Empty directory name Delete an empty directory

RM FileName File name Delete a file or multiple files

RM-RF non-empty directory name delete everything under a non-empty directory

MV Path/Document/warp/file movement relative to the path of the file to the absolute path

MV FileName New name renamed in current directory

Find Road via-name "string" finds paths in the range of files and directories that meet string matches

Fdisk fdisk-l viewing system partition information

FDISK FDISK/DEV/SDB partition a new SCSI hard drive

Chown chown Root/home Change the owner of/home to the root user

CHGRP chgrp root/home Change the home/home group to the root group

Useradd Create a new user

Groupadd group name to create a new group

passwd user name create password for user

passwd-d User name Delete user password can also login

Passwd-s User name Inquiry account password

Usermod-l new username old user name renamed to User

Userdel–r User name Delete user everything

TAR-C Create Package –x release Package-v Display command procedure –z represents a compressed package

TAR–CVF benet.tar/home/benet Pack The/home/benet directory

TAR–ZCVF BENET.TAR.GZ/MNT Package and compress the directory

TAR–ZXVF benet.tar.gz Compressed Package file decompression and recovery

TAR–JXVF benet.tar.bz2 Decompression

Make compilation

Make install installs the compiled source package

Reboot Init 6 Restart Linux system

Halt Init 0 shutdown–h now shut down the Linux system

Uname-a Viewing the kernel version

Cat/etc/issue View Ubuntu version

LSUSB Viewing USB devices

sudo ethtool eth0 view NIC status

Cat/proc/cpuinfo Viewing CPU information

LSHW Viewing current hardware information

sudo fdisk-l viewing disk information

Df-h viewing the remaining space on the hard disk

Free-m View Current Memory usage

PS-A See which processes are currently in progress

Kill process Number (the number of the first column in ps-a) or killall process name (kills a process)

Kill-9 process number forces a process to be killed

Common APT Commands:

Apt-cache Search Package

Apt-cache Show package for information about packages, such as description, size, version, etc.

sudo apt-get install package

sudo apt-get Install package--Reinstall reinstall packages

sudo apt-get-f install fix "-F =–fix-missing"

sudo apt-get Remove Package

sudo apt-get Remove Package--purge delete packages, including deletion of configuration files, etc.

sudo apt-get update source

sudo apt-get upgrade update installed packages

sudo apt-get Dist-upgrade upgrade system

sudo apt-get dselect-upgrade using Dselect upgrade

Apt-cache depends package learn about using dependencies

Apt-cache Rdepends package is to see which packages are dependent on

sudo apt-get BUILD-DEP Package Installation-related compilation environment

Apt-get Source Package Downloads The source code for the bundle

sudo apt-get clean && sudo apt-get autoclean cleanup of useless packages

sudo apt-get check to see if there is a corrupted dependency

Clean up all software caches (that is, the Deb packets that are cached in the/var/cache/apt/archives directory)

sudo apt-get clean

Remove orphaned software that is no longer used by the system

sudo apt-get autoremove

1. Division:/boot;

2.date # Date

Cal # when month calendar

Cal 1972 # The calendar of the year

Cal 7 1072 # when the calendar of the month

BC # Calculator (scale=3 #精確到小數點后3位)

ca [tab] [tab] # Show all instructions for CA opening (instructions)

The man command # explains what you want to borrow from the command.

sudo apt-get install Manpages-zh # installation Chinese version of Man

FSCK # Check and repair Linux file system

CD Change Catalogue

.. When the previous catalogue

. Previous entries

-Previous Job recording

~ Home Catalogue

PWD shows your current catalog

mkdir Create a new catalog-p to create a multi-level directory

RmDir Delete (empty) catalog-p to remove multi-level catalogs

LS View Archives and catalogue

CP Duplicate

RM move

MV Erase

chmod commands to control the reading, writing, and licensing of folders and files

Linux files have access rights in Tier 3: File holders + groups + others

R Read = 4

W Write write = 2

X Perform xactive = 1

Full Rights rwx = 7

Read rights rw-= 6

Only r-x = 5

In this case, the file's rights are: R+w+x r+w+x r+w+x

Example: 4+2+1 4+2+1 4+2+1 = 777: (File ownership + Group + other) has full rights to the file

4+2+1 0+0+0 0+0+0 = 700 means: Only (the files have) have full rights to the file

4+2+1 4+2+1 0+0+0 = 770 means: Only (Files with the group) have full rights to the file

Common rights are 600 644 700 755 711 666 777,666 and 777 are undesirable practices.

Chown is the root that can be used to change the person who owns the file.

Command line: Chown New archives: Group Archives

Example: Chown kevin/home/abc says: Only Kevin is the one who owns the home file ABC.

Chown Kevin:admin/home/abc says: Kevin and admin Group are all of the home under the ABC of the Holders

-R is the order to be handed over to all the files under the file

Linux command line