Tài liệu Tìm hiểu Linux doc

1.1 Overview1.2 Filesystem hierarchy 1.3 Type of information 1.4 Linux device files 1.5 Mounting and unmounting a device on thefilesystem 3...  Physical storage device: HDD, DVD-ROM se

MS Võ Minh Sơn

Students:

Nguyễn Đức Tiến 0620076 Nguyễn Xuân Thuận 0620069

1.1 Overview

1.2 Filesystem hierarchy

1.3 Type of information

1.4 Linux device files

1.5 Mounting and unmounting a device on thefilesystem

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 Physical storage device: HDD, DVD-ROM 

sector, track, cylinder

• HDDs can be divided into separate storage

devices called partitions

 A filesystem is the methods and data

structures that an operating system uses to keep track of files on a disk or partition (the way the files are organized on the disk)

• ext3 (third extended filesystem)

 File properties (Administrative information)

 File manager KDE  Konqueror

(Windows Explorer) GNOME Nautilus

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Data files

Link filesDirectory filesConfiguration files

Device files

Type of information

 Application-specific files

o Program Applications

o Image files

 Text files

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 Linux treats all devices as files and uses a device just as it uses a file

Open file Write file

Read file

Close file

 Device Driver: a special program that

controls a particular type of hardware

 Any application can access a device by opening the file specific to that device

 Device file: the file which applications use to

access a device

• These special appear in the /dev directory in

the Linux filesystem

• block devices  „b‟

character devices  „c‟

network devices  „ethx‟/„pppx‟ ( x = 0, 1, )

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 Each of storage device has own filesystem

• when you want to add a new storage device, you need to format it as a filesystem and then attach it to your Linux file structure

 Mounting is the operation you perform to

cause the filesystem on a physical storage device to appear as part of the Linux filesystem

 Mounting point is a specified directory that contains the mount command to mount a

device on the Linux filesystem

Mounting a device on the filesystem

 Example

• fd 0: the first floppy drive attached to your system

• sd a 2: the second partition on the first SCSI hard drive

hd IDE hard drive

1 – 4 are primary partitions

5 and up are logical partitions

sd SCSI hard drives

fd Floppy disks

lp Printer ports

cdrom Links to your CD-ROM device file

3 File Permissions

 Three types of user accounts

• Owner The account that owns the file

• Group Members of a group that owns the file

• All users All accounts on the system

 Do one or more of three things to the file

• Read (r) Look at the contents of the file

• Write (w) Save the file to the hard disk

• Execute (x) Run the file or enter the directory

 Example: drwxr-x

r 3 File Permissions (cont)

Format:

chmod who action permission filename

Example: chmod u+x nguyen.txt

4 File processing

4.1 Finding file

4.2 Creating Directories, Files, and Links4.3 Copying, Renaming, and Moving Files4.4 Viewing and Editing Text Files

4.5 Deleting Files and Directories

4.6 Backup and restoring files

4.1.1 Find command

find pathname conditions

4.1.2 Grep command

grep options pattern files

4.2 Creating Directories, Files, and Links

 To create a directory in any directory where you have write permission, use the mkdir

command:

mkdir path/dirname

 If path includes directories don't yet exist, you can create them in one command with the -p option:

mkdir -p /usr/local/newparent/mydir

4.2 Creating Directories, Files, and Links (cont)

 Files can be created by applications, such as

a word processor, and cat command

 Links can be created at the command line using the ln command

4.3 Copying, Renaming, and Moving Files

To copy or move a file, type:

(moves a file or directory)

Your account needs to have write permissions

4.4 Viewing and Editing Text Files

 Applications: Kate, Kwrite, …

 Command lines:

•cat filename: The entire file contents display

on the screen at once

•less filename: display the contents one

screen at a time

•vi filename: edit file

Vi options

Vi options (cont)

ZZ: save file

:q!: close without saving file

Vi options (cont)

4.5 Deleting Files and Directories

 rm filename: delete a file

 rm *: delete all file in current directory

 rmdir dirname: remove a empty directory

 rm -r dirname: remove a directory

 Must have write permissions on the directory containing the files

 +which files needing to back up

+how often

+what back up storage to use

Back up strategyBack up media

 tap archiver command (tar)

 Format: tar options tarfile filelist

Tar options

Tar options (cont)

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