Archiving & Transferrring Files

 

1. The tar command is used to compress a group of files into an archive. The command is also used to extract, maintain, or modify tar archives. Tar archives combine multiple files and/or directories together into a single file. 
2. In Linux TAR stand for "tape archiving" which is used to create maintain, modify and extract file.
3. Archiving and compressing files are useful when creating backups and transferring data across a network.
4. With tar, users can gather large sets of lines into a single file_(archive).
5. The archive can be compressed using
6. -gzip,bzip2 or xz compression.

Syntax of the "tar" command:

----------------------------

# tar [option] [archive-file] [file or directory to be archived]

Tar Operation
-c	This creat an archive file
-x	The operation extracts the archive file
-f	Specifies the filename of the archive file
-v	The prints verbose information for any tar operation on the terminal
-t	This lists all the files inside an archive file
-u	This archives a file and then adds it to an existing archive file
-r	This updates a file or directory located inside a .tar file
-z	Creates a tar file using gzip compression
-j	Create an archive file using the bzip2 compression
-J	The xz compression typically archives a bettwer compression ratio than bzip2.(tzr.xz)
-w	This option verifies an archive file
-p	Preserve the permission of the files and directories when extracting an archive.

Lab setup for practice:

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Task-) Create a new directory & create some files in new directory thereafter create a sub-directory with files in new directory.

[root@localhost ~]# mkdir abhishek_dir-1

Note:- "abhishek_dir-1" is a directory name. 

[root@localhost ~]# ll    (Show_Details)

total 8

drwxr-xr-x. 2 root root    6 May 18 15:50 abhishek_dir-1

-rw-------. 1 root root 1499 May 19  2021 anaconda-ks.cfg

drwxr-xr-x. 2 root root    6 May 18 15:46 Desktop

drwxr-xr-x. 2 root root    6 May 18 15:46 Documents

drwxr-xr-x. 2 root root    6 May 18 15:46 Downloads

-rw-r--r--. 1 root root 1771 May 19  2021 initial-setup-ks.cfg

drwxr-xr-x. 2 root root    6 May 18 15:46 Music

drwxr-xr-x. 2 root root    6 May 18 15:46 Pictures

drwxr-xr-x. 2 root root    6 May 18 15:46 Public

drwxr-xr-x. 2 root root    6 May 18 15:46 Templates

drwxr-xr-x. 2 root root    6 May 18 15:46 Videos

[root@localhost ~]# cd abhishek_dir-1/

Note:- This command is used to move into "abhishek_dir-1" dircetory.

[root@localhost abhishek_dir-1]# cat > Switch

This device work on data link layer of osi model.

[root@localhost abhishek_dir-1]# cat > Router

This device work on network layer of osi model.

[root@localhost abhishek_dir-1]# cat > Firewall

This device work on transport layer of osi model.

[root@localhost abhishek_dir-1]# ll

total 12

-rw-r--r--. 1 root root 50 May 18 15:59 Firewall

-rw-r--r--. 1 root root 48 May 18 15:58 Router

-rw-r--r--. 1 root root 50 May 18 15:58 Switch

[root@localhost abhishek_dir-1]# mkdir abhishek_Sub-Dir-1

[root@localhost abhishek_dir-1]# ll

total 12

drwxr-xr-x. 2 root root  6 May 18 16:11 abhishek_Sub-Dir-1

-rw-r--r--. 1 root root 50 May 18 15:59 Firewall

-rw-r--r--. 1 root root 48 May 18 15:58 Router

-rw-r--r--. 1 root root 50 May 18 15:58 Switch

[root@localhost abhishek_dir-1]# cd abhishek_Sub-Dir-1/

[root@localhost abhishek_Sub-Dir-1]# cat > active_topology

This type of topology need external power.

[root@localhost abhishek_Sub-Dir-1]# cat > passive_topology

This topology don't need external power.

[root@localhost abhishek_Sub-Dir-1]# ll

total 8

-rw-r--r--. 1 root root 43 May 18 16:12 active_topology

-rw-r--r--. 1 root root 41 May 18 16:12 passive_topology

Task-) create an archive file of "Redhat.tar"  via "tar" in "abhishek_dir-1" directory with files then use "-cvf":

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[root@localhost abhishek_dir-1]# tar -cvf Redhat.tar Firewall Router 

Firewall

Router

[root@localhost abhishek_dir-1]# ll    (Show_Details)

total 24

drwxr-xr-x. 2 root root    53 May 18 16:12 abhishek_Sub-Dir-1

-rw-r--r--. 1 root root    50 May 18 15:59 Firewall

-rw-r--r--. 1 root root 10240 May 18 16:21 Redhat.tar

-rw-r--r--. 1 root root    48 May 18 15:58 Router

-rw-r--r--. 1 root root    50 May 18 15:58 Switch

Task-) For "gzip" create an archive file of "Redhat-1.tar.gz"  via "tar.gz" in "abhishek_dir-1" directory with files then use "-z" between "-cvf":

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[root@localhost abhishek_dir-1]# tar -czvf Redhat-1.tar.gz Firewall Router

Firewall

Router

[root@localhost abhishek_dir-1]# ll        (Show_Details)

total 28

drwxr-xr-x. 2 root root    53 May 18 17:22 abhishek_Sub-Dir-1

-rw-r--r--. 1 root root    50 May 18 17:21 Firewall

-rw-r--r--. 1 root root   195 May 18 17:24 Redhat-1.tar.gz

-rw-r--r--. 1 root root 10240 May 18 17:22 Redhat.tar

-rw-r--r--. 1 root root    48 May 18 17:21 Router

-rw-r--r--. 1 root root    50 May 18 17:20 Switch

Task-) For "bzip2" create an archive file of "Redhat-4.tar.bz2"  via "tar.bz2" in "abhishek_dir-1" directory with files then use "-j" between "-cvf":

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[root@localhost abhishek_dir-1]# tar -cjvf Redhat-4.tar.bz2 Firewall Router

Firewall

Router

[root@localhost abhishek_dir-1]# ll         (Show_Details)

total 36

drwxr-xr-x. 2 root root    53 May 18 17:22 abhishek_Sub-Dir-1

-rw-r--r--. 1 root root    50 May 18 17:21 Firewall

-rw-r--r--. 1 root root   195 May 18 17:24 Redhat-1.tar.gz

-rw-r--r--. 1 root root   223 May 18 17:27 Redhat-4.tar.bz2

-rw-r--r--. 1 root root 10240 May 18 17:22 Redhat.tar

-rw-r--r--. 1 root root    48 May 18 17:21 Router

-rw-r--r--. 1 root root    50 May 18 17:20 Switch

Task-) For "xz" create an archive file of "Redhat-5.tar.xz"  via "tar.xz" in "abhishek_dir-1" directory with files then use "-J" between "-cvf":

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[root@localhost abhishek_dir-1]# tar -cJvf Redhat-5.tar.xz Firewall Router

Firewall

Router

[root@localhost abhishek_dir-1]# ll

total 40

drwxr-xr-x. 2 root root    53 May 18 17:22 abhishek_Sub-Dir-1

-rw-r--r--. 1 root root    50 May 18 17:21 Firewall

-rw-r--r--. 1 root root   195 May 18 17:24 Redhat-1.tar.gz

-rw-r--r--. 1 root root   223 May 18 17:27 Redhat-4.tar.bz2

-rw-r--r--. 1 root root   248 May 18 17:30 Redhat-5.tar.xz

-rw-r--r--. 1 root root 10240 May 18 17:22 Redhat.tar

-rw-r--r--. 1 root root    48 May 18 17:21 Router

-rw-r--r--. 1 root root    50 May 18 17:20 Switch

Task-) Show the contents of an archive file:-

----------------------------------------------

[root@localhost abhishek_dir-1]# tar -tf Redhat

Redhat-1.tar.gz  Redhat-4.tar.bz2  Redhat-5.tar.xz   Redhat.tar        

[root@localhost abhishek_dir-1]# tar -tf Redhat-1.tar.gz 

Firewall

Router

[root@localhost abhishek_dir-1]# tar -tf Redhat-4.tar.bz2 

Firewall

Router

[root@localhost abhishek_dir-1]# tar -tf Redhat-5.tar.xz 

Firewall

Router

[root@localhost abhishek_dir-1]# tar -tf Redhat.tar 

Firewall

Router

Task-) Adding new file in existing file via "-rvf":

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[root@localhost abhishek_dir-1]# tar -tf Redhat.tar 

Firewall

Router

[root@localhost abhishek_dir-1]# tar -rvf Redhat.tar Switch 

Switch

[root@localhost abhishek_dir-1]# tar -tvf Redhat.tar 

-rw-r--r-- root/root        50 2023-05-18 17:21 Firewall

-rw-r--r-- root/root        48 2023-05-18 17:21 Router

-rw-r--r-- root/root        50 2023-05-18 17:20 Switch

Task-) Remove or delete files from an archive via "-f":

----------------------------------------

[root@localhost abhishek_dir-1]# tar -tvf Redhat.tar 

-rw-r--r-- root/root        50 2023-05-18 17:21 Firewall

-rw-r--r-- root/root        48 2023-05-18 17:21 Router

-rw-r--r-- root/root        50 2023-05-18 17:20 Switch

[root@localhost abhishek_dir-1]# tar --delete Switch -f Redhat.tar

[root@localhost abhishek_dir-1]# tar -tvf Redhat.tar 

-rw-r--r-- root/root        50 2023-05-18 17:21 Firewall

-rw-r--r-- root/root        48 2023-05-18 17:21 Router

Task-) Add all files and sub-directory(abhishek_Sub-Dir-1) of the directory(abhishek_dir-1) in the Open_Source.tar.

----------------------------------------

[root@localhost abhishek_dir-1]# tar -cvf Open_Source.tar abhishek_Sub-Dir-1/

abhishek_Sub-Dir-1/

abhishek_Sub-Dir-1/active_topology

abhishek_Sub-Dir-1/passive_topology

[root@localhost abhishek_dir-1]# ll     (Show_Details)

total 52

drwxr-xr-x. 2 root root    53 May 18 17:22 abhishek_Sub-Dir-1

-rw-r--r--. 1 root root    50 May 18 17:21 Firewall

-rw-r--r--. 1 root root 10240 May 18 18:18 Open_Source.tar

-rw-r--r--. 1 root root   195 May 18 17:24 Redhat-1.tar.gz

-rw-r--r--. 1 root root   223 May 18 17:26 Redhat-2.tar.gz

-rw-r--r--. 1 root root   223 May 18 17:27 Redhat-4.tar.bz2

-rw-r--r--. 1 root root   248 May 18 17:30 Redhat-5.tar.xz

-rw-r--r--. 1 root root 10240 May 18 18:10 Redhat.tar

-rw-r--r--. 1 root root    48 May 18 17:21 Router

-rw-r--r--. 1 root root    50 May 18 17:20 Switch

[root@localhost abhishek_dir-1]# tar -tf Open_Source.tar 

abhishek_Sub-Dir-1/

abhishek_Sub-Dir-1/active_topology

abhishek_Sub-Dir-1/passive_topology

Task-) Unless any change is made in the files or directories which are archived. The update command does nothing.

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[root@localhost abhishek_dir-1]# tar -uvf Open_Source.tar abhishek_Sub-Dir-1/

[root@localhost abhishek_dir-1]# cat >> abhishek_Sub-Dir-1/active_topology 

Star topology is an Active Topology.               

[root@localhost abhishek_dir-1]# tar -uvf Open_Source.tar abhishek_Sub-Dir-1/

abhishek_Sub-Dir-1/active_topology

[root@localhost abhishek_dir-1]# tar -tf Open_Source.tar 

abhishek_Sub-Dir-1/

abhishek_Sub-Dir-1/active_topology

abhishek_Sub-Dir-1/passive_topology

abhishek_Sub-Dir-1/active_topology    (Updated Files )

Note:- Newly added, modified and updated files are placed in the end of the archie.

Task-) Delete "archive" files single & multiple:

------------------------------------------------

[root@localhost abhishek_dir-1]# ll

total 64

drwxr-xr-x. 2 root root    53 May 18 17:22 abhishek_Sub-Dir-1

-rw-r--r--. 1 root root    50 May 18 17:21 Firewall

-rw-r--r--. 1 root root 10240 May 18 19:02 Open_Source.tar

-rw-r--r--. 1 root root   195 May 18 17:24 Redhat-1.tar.gz

-rw-r--r--. 1 root root   223 May 18 17:26 Redhat-2.tar.gz

-rw-r--r--. 1 root root   223 May 18 17:27 Redhat-4.tar.bz2

-rw-r--r--. 1 root root   248 May 18 17:30 Redhat-5.tar.xz

-rw-r--r--. 1 root root 10240 May 18 18:10 Redhat.tar

-rw-r--r--. 1 root root    48 May 18 17:21 Router

-rw-r--r--. 1 root root    50 May 18 17:20 Switch

[root@localhost abhishek_dir-1]# rm -rf Redhat.tar 

[root@localhost abhishek_dir-1]# ll

total 52

drwxr-xr-x. 2 root root    53 May 18 17:22 abhishek_Sub-Dir-1

-rw-r--r--. 1 root root    50 May 18 17:21 Firewall

-rw-r--r--. 1 root root 10240 May 18 19:02 Open_Source.tar

-rw-r--r--. 1 root root   195 May 18 17:24 Redhat-1.tar.gz

-rw-r--r--. 1 root root   223 May 18 17:26 Redhat-2.tar.gz

-rw-r--r--. 1 root root   223 May 18 17:27 Redhat-4.tar.bz2

-rw-r--r--. 1 root root   248 May 18 17:30 Redhat-5.tar.xz

-rw-r--r--. 1 root root    48 May 18 17:21 Router

-rw-r--r--. 1 root root    50 May 18 17:20 Switch

[root@localhost abhishek_dir-1]# rm -rf Redhat-5.tar.xz Redhat-4.tar.bz2 

[root@localhost abhishek_dir-1]# ll

total 44

drwxr-xr-x. 2 root root    53 May 18 17:22 abhishek_Sub-Dir-1

-rw-r--r--. 1 root root    50 May 18 17:21 Firewall

-rw-r--r--. 1 root root 10240 May 18 19:02 Open_Source.tar

-rw-r--r--. 1 root root   195 May 18 17:24 Redhat-1.tar.gz

-rw-r--r--. 1 root root   223 May 18 17:26 Redhat-2.tar.gz

-rw-r--r--. 1 root root    48 May 18 17:21 Router

-rw-r--r--. 1 root root    50 May 18 17:20 Switch

Compressing and Decompressing archive:-

---------------------------------------

1. By default the "tar" command doesn't perform compression on archived files. But if require it can use the third party compression utility such as "gzip" and "bzip2" to compress and decompress the archived file.
2. The gzip compress faster but low compression ratio. To create and compress the archive file with gzip utility use the option "g" with option "cvf" as "cgvf" and use the file extension ".gz" with the archive file name.
3. The bzip2 compress slow but high compression ratio. To create and compress the archive file with bzip2 utility use the option "j" with option "cvf" as "cjvf" and use the file extension ".bz2" with the archive file name.

Following commands create the archive "abhishek_Sub-Dir-1.tar" from the "/home" directory without compression. with gzip compression and with bzip2 compression.

[root@localhost abhishek_dir-1]# tar -cvf abhishek_Sub-Dir-1.tar /home/

[root@localhost abhishek_dir-1]# tar -czvf abhishek_Sub-Dir-1.gz /home/

[root@localhost abhishek_dir-1]# tar -cjvf abhishek_Sub-Dir-1.bz2 /home/

To view the size of compressed archive file, once compression is done use "du" command with the option "-h".

[root@localhost abhishek_dir-1]# du -h abhishek_Sub-Dir-1.tar 

11M abhishek_Sub-Dir-1.tar    (No Compress)

[root@localhost abhishek_dir-1]# du -h abhishek_Sub-Dir-1.gz

1.4M abhishek_Sub-Dir-1.gz    (gzip compression)

[root@localhost abhishek_dir-1]# du -h abhishek_Sub-Dir-1.bz2

1.1M abhishek_Sub-Dir-1.bz2    (bzip2 compression)

Note:- "Once an archive file is compresses, advance operations such as append update and individual delete can not performed with it."

Task-) To extract a compressed archive, use the same option

[root@localhost abhishek_dir-1]# tar -xvf abhishek_Sub-Dir-1.tar 

[root@localhost abhishek_dir-1]# tar -xzvf abhishek_Sub-Dir-1.gz 

[root@localhost abhishek_dir-1]# tar -xjvf abhishek_Sub-Dir-1.bz2 

=================================================================

Secure Copying Files Between Host:-

-----------------------------------

1. The scp command is secure way to transfer files between servers. It encrypts both the end password during transmission, ensuring secure file transfer.
2. scp stands for Secure Copy Protocol.
3. It's used to securely transfer files between a local and a remote host.
4. scp use SSH (Secure Shell) protocol to encrypt the files being transferred.
5. Usually scp use port number 22.
6. By default SCP using "AES-128" to encrypt files.
7. 
   
8. scp or secure copy encrypts files and transfer them from one host to another on a network. It uses SSH to establish a secure connection.

Basic Usage of scp command:-

----------------------------

1. Use the syntax scp [option] [destination] to initiate a file transfer.
2. # scp src_file_name username@dest.hostname:dest_path
3. Specify the location of the source file and the destination where the file should be transferred.
4. Use the -P option followed by the port number to specify a non-default port for the transfer.

Secure Copy File Option
-P	specify the port number of the remote host.
-r	copy directories recursively.
-v	verbose mode to display the progress of the transfer.
-p	Preserves files modification and access times.
-C	This option forces scp to compresses the data as it is sent to the destination machine.

Thanks & Regards

Abhishek Pathak

+91-9621134014

abhishek9621134014@outlook.com