# Remote Copying Tools, Archiving Tools, Backup & User Management These are the topics that are covered in today's session. @[Pranav Jambare](@AutomateMaster) ### **Remote Copying Tools:** ### **1 . SCP :** * SCP stands for **secure copy** command in Linux. * It is used to copy the files between the servers **securely**. * It allows the secure transfer of files between the ***local host*** and the ***remote host*** or between ***two remote hosts***. ```bash #Syntax : scp @: ``` ```bash #Example: scp myLinuxFile root@192.168.100.7:/root ``` ### **2 . RSYNC:** * RSYNC stands for remote synchronisation command in Linux. * It synchronizes files from a source to a destination. * It is famous for its **delta-transfer algorithm**, which **reduces** the amount of data sent over the network by sending only the **differences** between the source files and the existing files in the destination. * RSYNC finds files that need to be transferred using a **checksum** algorithm that looks for files that have changed in size or in the **last-modified** time. ```bash #Syntax: rsync -av @: ``` ```bash #Example: rsync -av myLinuxFile root@192.168.100.7:/root ``` ### **3 . SFTP:** * SFTP stands for **Safe File Transfer Protocol**. * It is a **secure variant** of **FTP**. * It is a part of the **SSH** Protocol and is designed to **securely** transfer files between remote systems via a **network** connection. ```bash #Syntax: sftp @ ``` ```bash #Example: sftp linuxUser@192.168.100.7 ``` --- ### **Archiving Tools:** * Archiving is the process of **combining multiple files** into a **single package** called an **archive**. * This archive can then be easily backed up, or simply kept on your machine as a way to organize your file system. ### 1 . **gzip** ```bash #Syntax : (Compress) gzip #Example : gzip myFile ``` ```bash #Syntax : (Decompress) gunzip .gz #Example : gunzip myFile.gz ``` ### **2 . xz** ```bash #Syntax: (Compress) xz #Example: xz myFile ``` ```bash #Syntax: (Decompress) unxz .xz #Example: unxz myFile.xz ``` ### **3 . bzip2** ```bash #Syntax: (Compress) bzip2 #Example: bzip2 myFile ``` ```bash #Syntax: (Decompress) bzip2 .bz2 #Example: bzip2 myFile.bz2 ``` --- ### **Backup:** ![Regular files being added to an archive with tar and then compressed with gzip.](https://cdn.hashnode.com/res/hashnode/image/upload/v1689087829751/8c63f4dd-7f5c-42ba-b610-dff65e5b9127.webp align="center") Fig. Regular files being added to an archive with tar and then compressed with gzip. * The tar utility is also able to compress an archive via a compression tool. * To create an archive file : ```bash #Syntax: tar -cvzf #Example: tar -cvzf myLinuxFile.backup file1 file2 file3 ``` * To extract an archive file: ```bash #Syntax: tar -xvf #Example: tar -xvf myLinuxFile.backup ``` --- ### **User Management:** * A user is an entity, that can **manipulate** files and **perform** several other operations. * Each user is assigned an ID that is unique for each user in the operating system. * The **ID 0** is assigned to the **root user** and the **IDs 1 to 999** are assigned to the system users, hence the ids for the local user begin from 1000 onwards.  **1 . Adding the User :** * The command "***useradd***" or "***adduser***" can be used to create a new user in Linux also, the sudo permissions are required to perform this command. ```bash #Creating a User: root@myLinux:~# useradd testuser #OR root@myLinux:~# adduser testuser ``` **2 . Verifying the User:** ```bash root@myLinux:~# id testuser uid=1001(testuser) gid=1001(testuser) groups=1001(testuser) ``` **3 . Deleting the User:** ```bash root@myLinux:~# userdel testuser ``` **4 . Managing the password policy:** **Fields of /etc/password file:** ```bash #The sudo permissions are required to perform this command root@myLinux:~# cat /etc/passwd|tail -1 testuser:x:1001:1001::/home/testuser:/bin/sh ``` Where, > testuser --> **Name of user** > > x --> **Encrpyted password** > > 1001 --> **User id** > > 1001 --> **Group id** > > :: --> **Nickname (Con-name)** > > /home/testuser --> ***Home directory of the user*** > > */bin/bash* *\-->* ***Default shell of user*** --- **Setting the password :** ```bash #The sudo permissions are required to perform this command root@myLinux:~# passwd testuser #Next... New password: 123 Retype new password: 123 passwd: password updated successfully ``` --- **Changing the password policy:** ```bash root@myLinux:~# chage -M 2 -m 5000 -W 4 -I 12 -E 2024-12-2 ``` Where, > \-M --> maxdays password change date > > \-m --> mindays password change date > > \-W --> warning > > \-I --> Inactivity > > \-E --> Account Expiry date --- **5 . Change / Restrict the User:** **Give "No Login" to the User:** ```bash root@myLinux:~# usermod testuser -s /sbin/nologin #Verifying... root@myLinux:~# su - testuser Cannot change directory to /home/testuser: No such file or directory This account is currently not available. ``` **To revert the changes to get a login:** ```bash root@myLinux:~# usermod testuser -s /bin/sh #Verifying... root@myLinux:~# su - testuser Last Login : ..... $whoami testuser ``` --- **6 . Lock and Unlock User:** ```bash # To Lock the user: root@myLinux:~# usermod -L testuser # To Unlock the user: root@myLinux:~# usermod -U testuser ``` --- **7 . Adding Group:** ```bash #The sudo permissions are required to perform this command root@myLinux:~# groupadd testgroup #Verifying the group... root@myLinux:~# cat /etc/group|tail -1 testgroup:x:1002: ``` --- **8 . Adding a user to a group:** ```bash root@myLinux:~# usermod -G testgroup testuser #Verifying... root@myLinux:~# id testuser uid=1001(testuser) gid=1001(testuser) groups=1001(testuser),1002(testgroup) ``` --- **9 . Deleting a group:** ```bash root@myLinux:~# groupdel testgroup #Verifying... root@myLinux:~# id testuser uid=1001(testuser) gid=1001(testuser) groups=1001(testuser) ``` --- **10 . Change the user-id of the user:** ```bash root@myLinux:~# usermod -u 1005 testuser #Verifying... root@myLinux:~# id testuser uid=1005(testuser) gid=1001(testuser) groups=1001(testuser) ``` ---