Learn about sudo name resolution and ways it can fail.
Driven by self-improvement and self-sufficiency. Self-motivated and self-disciplined. Dependable. Minimalist perfectionist. Problem solver. Can work on and improve anything related to IT.
Here's what I've written (so far):
Baeldung on Linux
- Administration (62)
- Scripting (41)
- Processes (36)
- Networking (25)
- Security (18)
- Filesystems (17)
- Files (16)
- File Editing (14)
- Installation (13)
- File Permissions (8)
- File Viewing (6)
- Web (4)
- File Compression (4)
- File Searching (1)
- Building (1)
Learn about special permissions, as well as ways to use the POSIX standard find command to search for files based on different permissions-related criteria.
Explore text and code folding and the ways it works within the Vi editor.
Explore block sizes in Linux and how to manipulate them.
Explore the audio setup in Linux and how to cut off sound completely.
Learn about the similarly-named who and whoami commands.
Learn about the ARP cache and ways to drop entries from it.
Learn about mounting, parallel mounts, and remounts in terms of the permissions the attached location has.
Learn about data types and the test or  builtin of Bash.
Explore the practical basics of the CUPS system.
Explore ways to check the UUID of the swap partition.
Learn about Base64 and methods to find Base64 strings via different means.
Explore OpenPGP and GnuPG, their common ground and differences.
Explore routing checks and changes, as well as errors that might result from them.
Explore different major filesystems, their constraints, and the maximum directory size of each.
Explore ways to test the configuration of /etc/hosts as the default hosts file of most Linux distributions.
Explore ways to change the text case of strings and files.
Explore ways to extract the extension from a filename.
Explore the definition and function of a storage UUID and how to change it for a given partition.
Learn about the wheel group, its function, and name origin.
Explore two kernel parameters that are often part of default installations and affect the boot process cosmetically.
Explore one of the most common URL encoding methods as well as an option curl provides for automating that.
Look at the Polkit mechanism to regulate, authenticate, and authorize user access.
Explore ways to disable and enable devices on a Linux system with a main focus on the internal keyboard of a laptop.
Explore the concept of truncation and learn how it differs from deletion.
Explore how to represent second timespans in common time formats.
Explore memory randomization in Linux with the ASLR feature.
Explore the repositories of Debian and the Debian-based Ubuntu. Learn how to restore the default repository list.
Learn about context size constraints and environment variable constraints in particular.
Learn about splitting and recombining PDF files and pages with different tools.
Explore the requirements and methods for sending e-mails via curl.
Learn about OpenSSL deployment and dependency problems and how to remedy them.
Learn how to disable the automatic configuration of IPv6.
Learn about the libtool and its .la files.
Explore ways to get the permissions of filesystem objects under or along a given path.
Learn about IP forwarding within the Linux kernel.
Learn about using shell variables within and as AWK patterns.
Explore welcome banners and messages, as well as how to configure and use them.
Explore the source of the uptime command time baseline, as well as the general Linux boot time start.
Explore ways to load kernel modules on boot and automate modprobe.
Explore security policies and how their implementation in ImageMagick works.
Learn about positioning the cursor and view in the Vi editor.
Explore ways to insert a newline in a shell command.
Learn about the special place of zero and NULL in Linux and computing, as well as ways to display, output, and type the NULL character.
Learn about killing and restarting a tmux pane.
Learn about tee and ways to assign command output to a variable.
Learn about the tee command, buffers, and pipes and how those concepts relate to the use of output from Python.
Explore one of the main swap settings – swappiness.
Explore keyboards, pressing a key, the modifier keys and combinations, as well as how we detect, interpret, and output the latter at different levels.
Learn about the backslash character and how to remove it from a file or string.
Explore the original and DNF YUM versions, as well as how to install, uninstall, and debug them.
Explore ways to extract the filename from a path via AWK.
Learn about the UNIX epoch timestamp, how to do arithmetic with the format, and how to use it to your advantage.
Learn about setting up and disabling SELinux.
Explore the concept of a umask and how to configure its global value.
Explore several methods of limiting and preventing the use of IPv6 in NGINX.
Learn about the du command and ways to get the total size of files with a given extension.
Explore how to list all SSL certificates in the default store of a Linux machine.
Explore the RFC-3339 standard and ways to produce dates based on it.
Learn about removing whitespace while preserving newlines.
Explore the reasons for a distorted prompt position and how to work around them.
Explore several tar implementations along with their differences and similarities.
Explore fully-open directories in Linux, their behavior, and how to identify them.
Explore the system uptime and its relation to top and htop.
Explore many ways to output the executables within the $PATH environment variable directories.
Learn about terminal allocation and the role of requiretty when using sudo.
Explore kernel permissions, the modprobe command, as well as the “Operation not permitted” error when trying to load a module.
Explore ways to supply binary data directly to commands with the primary example of curl.
Explore browsing Microsoft Windows administrative shares from Linux.
Explore the settings of standard and transparent huge pages, as well as how to check their status and disable them completely.
Explore ways to limit the filesystems find traverses.
Learn a sed-only way to delete the first line of a file while also printing it with a single command.
Explore ways to change the Linux temporary directory path.
Explore unit files and their permissions.
Explore ways to find path elements with names that contain special characters.
Explore different ways to generate many files.
Explore ways to remove comments from a Bash script.
Explore ways to extract the content between two HTML tags in the shell.
Learn about network processes and why they might seem to lack a PID.
Learn how to change the owner of a mount point and location.
Learn about serial numbers, universal unique identifiers, and their role in network interfaces.
Learn how to set limits within systemd units.
Explore ways to add and remove zero padding in a standard POSIX environment.
Explore NGINX timeouts and their settings.
Explore ways to check and set NGINX’s default and current document root paths.
Explore ways to send a signal that doesn’t stop or terminate a process.
Learn about domain TXT records with different tools, exploring some details of the process.
Explore ways to use shell variables when changing to a new path.
Explore the initialization process of the Vi editor when it comes to settings and configuration files.
Learn about CMake and make to understand how to change options like the installation destination path.
Explore ways to split text only at newlines in the shell.
Explore the ARP protocol implementation in Linux and focus on its available settings.
Learn about the duplicates in the Bash history list, as well as how to deal with them.
Learn how to close a terminal on several levels.
Learn about the output of watch and how to capture that in a file.
Learn how to switch session modes with different FTP clients.
Explore leading slashes and absolute paths, as well as their consequences when using tar.
Learn ways to log in to an FTP, FTPS, and SFTP server automatically.
Explore basic and advanced ways to search in Vi.
Learn how to remove files from the /tmp directory safely.
A quick and practical guide to disabling the beep sound in Linux.
Learn how to handle directory creation while mirroring with wget.
Learn how to install a Debian package directly from a URL.
Learn how three ways to elevate a session differ.
Learn how to remove the password from SSH keys via two common SSH suites.
Learn about modifying passwords and how to do that for the root user without first using su.
Explore how to pass values of shell variables to AWK for internal use.
Explore ways to work with links instead of their targets.
Explore ways to organize the use of multiple private keys with SSH.
Learn a standard way to relocate relative symbolic links without severing the connection with their target.
Explore methods to extract an identity from a Linux system.
Explore ways to convert simple text files to PDF from the command line.
Learn about passwords with special characters and ways to handle them.
Explore system calls, library calls, and how they differ.
Learn how to perform a comparison between a local and a remote directory.
Explore many ways to handle JSON in the shell.
Explore newlines, how they can affect file processing, and what we can do about it.
Learn about our options when an initialization process is the parent of a zombie.
Learn if terminal supports colors and ways to detect it.
Learn about character positioning and how to employ it when moving the cursor.
Explore the PDF file format, how to view its contents, as well as tools that can handle and manipulate it under Linux.
Learn about built-ins, commands, binaries, and other executables that do nothing.
Learn about locales, how they are used in Linux, and checking the encoding in different environments.
Explore sudo sessions, why we need them, and how to control their lengths.
Explore ways to check which packages on a given system currently have upgrades.
Explore common causes for malformed SSH keys, as well as their consequences.
Learn why attempting to kill a process might not always succeed and what we can do about it.
Explore ways to work with and preserve the environment of a sudo session.
Explore different ways to preserve our changes and save a file opened without write permissions in Vi.
Explore different ways to indent in the Vi editor and how to set the indentation amount.
Explore types of system identifiers, numeric address to name resolution, and whether the latter is case-sensitive.
Explore how to generate passwordless SSH keys with three common tools.
Learn how to remedy global permission issues.
Explore one simple and one complex but precise way to search for class files within JAR files under a given directory.
Explore the /etc/shadow file and its options to set passwords.
Explore the arp command along with its options.
Learn how to automate commands in Vi.
Look at address space files available in Linux.
Explore usual commands for stopping and restarting a Linux system, some of their history, and their current status quo.
Explore ways to disable cron and anacron tasks, as well as how to reenable them at a later stage.
Explore ways to limit resource usage for a given process, with the main example of lowering the maximum number of open file handles.
Explore the limits of FAT32 regarding the size of files, how they affect archive extraction, and what we can do to avoid problems.
Explore the anacron and cron tools, their configuration file structure, and a simple way to back them up.
Explore network configuration under many different Linux distributions, with the main goal of setting a static IP address.
Explore steps necessary to create a user manually without the help of useradd and adduser.
Explore the iptables rules for leaving a machine open only to SSH traffic.
Explore ways to use name resolution with SSH.
Explore ways to execute remote commands when establishing an SSH session with the example of a simple directory change.
Explore PuTTY and OpenSSH, their key types and formats, as well as how to convert between them.
Learn how to work with public and private key comments via both the OpenSSH and PuTTY toolsets.
Explore the known_hosts file structure and ways to ignore the known hosts from an SSH client.
Learn about the SSH authentication methods.
Explore SSH key permissions, problems they may cause, and how to correct them.
Explore ways to get the physical partition a file or directory is located on.
Learn how to start an SSH server on multiple ports.
Explore sudo, its sudoers plugin, its configuration, and various ways to change it.
Explore the differences between /dev/sda and /dev/vda.
Explore many ways to check whether multicast is supported and enabled in a given system.
Learn about drive mapping and mounting.
Explore the most common way to disable IPv6 on modern Linux distributions.
Learn how to get the true size of a file.
Learn why we might not be able to change into a given directory in Linux.
Learn how to forcefully unmount an SMB connection when it’s not responding.
Explore ways to run shell commands and suppress their output while preventing session takeover within the Vi editor.
Learn how to identify whitespaces in the Vi editor.
Explore relative and absolute file paths, concentrating on ways to show the full path of the current file in the Vi editor.
Learn about soft and hard limits in the context of resource usage restrictions.
Explore indenting in Vi and ways to avoid problems with automatic indentation and formatting when pasting contents to the editor.
Learn what comprises a TTY, how it comes to life, and how we can dispose of one.
Explore different ways to kill constantly restarting processes.
Learn how to break a terminal and restore an already broken one.
Explore TTYs, PTYs, and the differences between them.
Explore single-line if-else statements in contrast to their regular multi-line forms.
Learn how less could show special characters, as well as the notation it uses to do so.
A quick and practical explanation why newlines are required when working with Linux files.
Learn how to handle overburdened terminals with the primary example of a runaway cat command.
Learn about terminal shortcuts in Linux.
Explore the comprehensive auditd package in Linux.
Explore the general idea of attached and detached processes.
Explore ways to get the behavior of the Windows Batch pause in Linux.
Explore rc, its meaning, and how it could hint at the contents of a file or directory.
Explore options to check and monitor the active video card of a Linux system.
Explore many ways of checking how old a Linux system is.
Discuss methods for efficiently deleting a directory in Linux.
Explore many ways data can be lost, damaged, or deleted and discuss diagnosis, repair, and recovery in all cases.
Explore the inotify Linux subsystem, used by many applications.
Explore how to check a machine’s external IP address via a Bash shell script.
Learn about text objects and how to use them in the Vi editor.
Explore how grep can be used with continuous streams of data.
Explore inodes and their major role in filesystems.
Explore different ways to get data back to the client after and during an SSH session to a server.
Explore acquiring a Bash script’s location from within the script.
Discuss character escaping in Bash.
Explore debugging with the GNU Project Debugger.
In this tutorial, we’ll see into different ways of using timeouts in Bash.
An overview of errors in Bash.
Explore different Bash implementations for 2D arrays, along with their downsides.
Learn some common problems and explore tools that help when partially processing huge files
Learn about what Linux desktop entry files are, why they are useful, and how they function.