Linux Command Learning (4): cd command, linuxcd

Linux Command Learning (4): cd command, linuxcd

The Linux cd command is the most basic command statement in Linux. Other command statements are created on the cd command. Therefore, to learn common Linux commands, you must first learn how to use cd commands.

 

1. Command Format:

 

Cd [directory name]

  2. command functions:

 

Switch the current directory to dirName

 

3. Common examples

 

Example 1: Enter the system root directory

 

Command:

 

Cd/

 

Output:

 

[Root @ localhost ~] # Cd/

 

Note: Go to the system root directory. Take a look at the ls command after the above command is executed. The current directory is already in the system root directory.

 

Command:

 

Cd... or cd ..//

 

Output:

 

[root@localhost soft]# pwd
/opt/soft
[root@localhost soft]# cd ..
[root@localhost opt]# cd ..//
[root@localhost /]# pwd
/

 

Note:

 

To enter the root directory of the system, you can use "cd .." to continue to return to the root directory.

 

Command:

 

Cd ../..//

 

Output:

 

[root@localhost soft]# pwd
 /opt/soft
 [root@localhost soft]# cd ../.. //
 [root@localhost /]# pwd
 /
 [root@localhost /]#

 

Note: run the cd command to access the parent directory of the current directory.

 

Example 2: run the cd command to enter the home directory of the current user.

 

"Current user home directory" and "system root directory" are two different concepts. There are two methods to enter the current user's home directory.

 

Command 1:

 

Cd

 

Output:

 

[root@localhost soft]# pwd
 /opt/soft
 [root@localhost soft]# cd
 [root@localhost ~]# pwd
 /root

 

Command 2:

 

Cd ~

 

Output:

 

[root@localhost ~]# cd /opt/soft/
[root@localhost soft]# pwd
/opt/soft
[root@localhost soft]# cd ~
[root@localhost ~]# pwd
/root

 

Example 3: Jump to the specified directory

 

Command:

 

Cd/opt/soft

 

Output:

 

 [root@localhost ~]# cd /opt/soft
 [root@localhost soft]# pwd
 /opt/soft
 [root@localhost soft]# cd jdk1.6.0_16/
 [root@localhost jdk1.6.0_16]# pwd
 /opt/soft/jdk1.6.0_16
 [root@localhost jdk1.6.0_16]#

 

Note:

 

Jump to the specified directory, starting from the root directory, and add/before the directory name. You can directly write the name of the subdirectory in the current directory.

 

Example 4: return the directory before entering this directory

 

Command:

 

Cd-

 

Output:

 

[root@localhost soft]# pwd
 /opt/soft
 [root@localhost soft]# cd -
 /root
 [root@localhost ~]# pwd
 /root
 [root@localhost ~]# cd -
 /opt/soft
 [root@localhost soft]#

 

Example 5: Use the parameters of the previous command as the cd parameter.

 

Command:

 

Cd! $

 

Output:

 

# cd !$
 cd -1 [root@localhost soft]# cd !$
 cd -
 /root
 [root@localhost ~]
 /opt/soft
 [root@localhost soft]#