Files and Directories

Files and Directories29

❯

User Management

User Management16

❯

Linux Topics Index

Next Topic ⮕How to Create a File in Linux

Linux How-To Topics

1. Files and Directories

How to create a file
How to rename a file
How to copy a file
How to move a file
How to delete a file
How to create a directory
How to delete a directory
How to copy directories recursively
How to delete directories recursively
How to view hidden files
How to create a hidden file or directory
How to find files using find and locate
How to view file contents using cat
How to view file contents using less
How to view file contents using more
How to compare files using diff
How to compare files using cmp
How to check the file type using file
How to create symbolic links using ln -s
How to archive files using tar
How to compress files using gzip
How to compress files using bzip2
How to compress files using zip
How to extract compressed files (tar, unzip, gunzip)

2. User Management

How to add a new user
How to modify an existing user
How to delete an existing user
How to create a user group
How to add a user to a group
How to remove a user from a group
How to delete a user group
How to switch users using su
How to execute commands as another user using sudo
How to change a user’s password using passwd
How to set password expiry rules using chage
How to lock and unlock a user account
How to configure user login shell
How to configure user environment variables
How to edit a user's profile and startup files (.bashrc, .profile)

3. Permissions and Ownership

How to view file permissions
How to change file permissions using chmod
How to use numeric mode with chmod
How to use symbolic mode with chmod
How to change file ownership using chown
How to change group ownership using chgrp
Understanding permission symbols: r, w, x
Understanding permission types: user, group, others
Understanding special permissions: SUID, SGID, Sticky bit
How to use Access Control Lists (ACLs)
How to set ACL permissions using setfacl
How to view ACLs using getfacl
How to find files with specific permissions

4. Package Management

How to install packages using apt
How to remove packages using apt
How to install packages using yum
How to install packages using dnf
How to install packages using pacman
How to update package lists
How to upgrade installed packages
How to perform a full system upgrade
How to search for packages
How to list all installed packages
How to check package details (version, dependencies)
How to verify if a package is installed
How to clean up unused packages and cache
How to add a new software repository
How to remove or disable a repository
How to manage PPA (Personal Package Archives) in Ubuntu
How to compile software from source (configure, make, make install)
How to remove software installed from source

5. Processes and Services

How to list processes using ps
How to monitor real-time processes using top
How to use an advanced process viewer with htop
How to check memory usage using free
How to kill a process using kill
How to kill a process by name using pkill or killall
How to restart a process
How to adjust process priority using nice and renice
How to run jobs in background and foreground (bg, fg, jobs)
How to manage services using systemctl
How to manage services using service (legacy systems)
How to view service logs using journalctl
How to schedule tasks using cron
How to schedule one-time tasks using at

6. Networking

How to view IP address using ip and ifconfig
How to list and manage network interfaces
How to configure a static IP address
How to configure DHCP settings
How to test internet connectivity using ping
How to trace route to a host using traceroute
How to test HTTP connectivity using curl
How to download files using wget
How to connect to a remote server using ssh
How to copy files between systems using scp
How to manage the firewall using ufw
How to manage the firewall using iptables
How to open and close ports in the firewall
How to check listening ports using netstat or ss
How to view active connections and sockets

7. Disk and Filesystem Management

How to list disks and partitions using lsblk
How to view disk details using blkid and df -h
How to mount and unmount disks
How to mount ISO files or loop devices
How to format drives and partitions
How to create a filesystem using mkfs
How to manage disk partitions with fdisk and parted
How to label a disk or partition using e2label or tune2fs
How to check disk usage using df and du
How to check and repair filesystems using fsck
How to find disk UUIDs using blkid
How to configure automatic mounting with /etc/fstab
How to check disk health with smartctl

8. System Information and Logs

How to check system information using uname
How to check system hostname using hostname
How to check hardware details using lshw
How to check CPU information using lscpu
How to check block devices using lsblk
How to read system log files from /var/log
How to monitor boot logs using journalctl
How to view shutdown logs
How to use dmesg for kernel ring buffer logs

9. Shell Scripting

How to write a basic shell script
How to use variables in shell scripts
How to use loops in shell scripts
How to use conditionals in shell scripts
How to use functions in shell scripts
How to read user input in shell scripts
How to handle command line arguments in shell scripts
How to use exit status and return codes
How to include comments in shell scripts
How to make a script executable
How to schedule scripts using cron
How to schedule one-time scripts using at
How to log output of shell scripts
How to debug shell scripts

10. Security

How to set up SSH keys
How to change default SSH port
How to configure firewall using ufw
How to allow or block specific ports
How to disable root login via SSH
How to enable and configure fail2ban
How to check active network connections
How to scan for open ports using nmap
How to enable and configure SELinux
How to enable and configure AppArmor
How to check for user login history (last, w)
How to set file and directory permissions securely
How to audit logs for suspicious activity

Next Topic ⮕How to Create a File in Linux

Files and Directories❯