Junior Level Linux Certification

Exam Objectives

Key Knowledge Areas

Create links. Identify hard and/or softlinks. Copying versus linking files. Use links to support system administration tasks.

Objective 4: Devices, Linux Filesystems, Filesystem Hierarchy Standard

Create and change hard and symbolic links Weight: 2

Terms and Utilities

ln

2

Create and change hard and symbolic links

Disk file format

3

Create and change hard and symbolic links

inodes

4

Create and change hard and symbolic links

inodes

5

Hard link

hard link maintains the same permissions and access times of the original file both have same inode number - simply appears to have different filename and/or location

6

Create and change hard and symbolic links

•Changes to either the original file or the link affect both. •The two files have equal importance. But deleting either of files won’t affect the other.•Hard link files appear to be regular files when examined and they function this way as

well• Normal users can’t create hard links to directories. • Also, hard links aren’t allowed to span file systems

To create a hard link, use the ln command

# ln stuff2 /home/angie/stuff# ls –al

-rw-r--r-- 2 root root 89704 Aug 27 2000 stuff-rw-r--r-- 2 root root 89704 Aug 27 2000 stuff2

Ex:

Create and change hard and symbolic links

Hard links

7

Symbolic link

Users can create symbolic links to directories, and symbolic links can span file systems.

8

Create and change hard and symbolic links

• Symbolic link maintains permissions separate from those of the original file. • Deleting the original file won’t remove the symbolic link, but the link wont funtion.

To create a soft link, you use the ln command.

# ln –s stuff /home/angie/stuffEx:

Soft links can be identified by listing the details of a directory’s contents:

# ls –al

lrwxrwxrwx 1 angie angie 7 Mar 10 17:06 stuff -> /fun/stuff

Ex:

Create and change hard and symbolic links

Symbolic links

9

Create and change hard and symbolic links

Symbolic Links to Different File Systems

10

Create and change hard and symbolic links

Multiple Links to One File

11

Fim de sessão

12