#linux

Reset atd command counter
Mount software RAID volumes - overcome unknown filesystem type 'linux_raid_member'
Verify ext4 filesystem for errors
Verify xfs filesystem for errors
More examples on scheduling jobs with at
Get LDAP users from /etc/passwd in Linux
Search for multiple words with apropos in Linux
ip a with colors
grep processes
Reboot and shutdown in Linux
tar autocompress
Remove empty directory in Linux: rmdir and rm -d
Difference between /usr/local and /opt in Linux
OnWorks - free Linux workstation available from the browser
Create usernames that do not conform to standards in Linux
Create GPT partitions with gdisk in Linux
Show brief output in ip
More Linux network tools
Non-graphical browsers in Linux
More tr examples
Split and combine files in Linux
join command example
Example of paste command
Scheduling tasks with at
Important /proc paths
Changing top display parameters
patch in Linux
Task scheduling in Linux
Set timezone in Linux
Show scripts that may be present in a RPM package
Understanding Linux
Extract password protected zip files in Linux
Enable time syncronization in Linux
Simple forest display with ps
ip command examples in Linux
Network device naming in Linux
Get/set system hostname in Linux
Create a loop device from a file in Linux
Add users to a group in Linux
Defaults for new user in Linux
Edit passwd, shadow and group files in Linux
Basic permissions for files and directories in Linux
Create user home directory with useradd
Disallow sudo command for specific user
View all manpages of a specified topic
Show all pages on the topic in man
List rpm package dependencies
Show line numbers in less
Filesystems supported by Linux
Configuration file to specify installation options in Linux distributions
tar z,j,J - options for compress with gzip, bzip2, xz
tar -C - switch the output path
Copy using cp to include hidden files and hidden directories and their contents in Linux
whoami
Verify if Linux kernel supports Seccomp
Changing shared memory size in Linux
Two trivial methods to truncate a file in Linux
Display type of filesystem in df
sudo groups in RHEL and Debian
Syslinux bootloaders
How to get yesterday’s date in Linux
sshfs remote mount in Linux
Linux groupmod quick reference
Create a new group with the specific GID in Linux
Delete user and its home directory in Linux
Create a new user with the specified UID in Linux
newgrp - log in to a new group in Linux
List specific user processes in Linux
useradd option -r - add system account
LVM usage examples in Linux
Get SSH RSA key fingerprint
Linux LVM - layers of abstractions
Label ext filesystems in Linux
Viewing disks labels and UUIDs in Linux
sudoers file format
Show the list of coomands that can be run with sudo
List all signals that can be sent to a Linux process
strings command in Linux
Example of column command in Linux
Explaining diff output
Basic keys for editing with emacs
umask with symbolic mode in Linux
Synonim for groups command in Linux
tree
Listing files by type in Linux
Example of useradd in Linux
Get other users homes in Linux by using tilde
Linux capabilities header file location
Show listening ports with lsof in Linux
Get running process capabilities in Linux - easy way
Get running process capabilities in Linux - hard way
Get capabilities of a binary in Linux
htop
Linux tools for persistent network configuration
Tune swap settings in Linux
Trace syscalls in Linux
Exclude certain directories from du in Linux
Create swap file on CentOS XFS filesystem
Display top results sorted by memory usage in Linux
Detect block size for target partition in Linux
Check the size of disk partition with blockdev in Linux
Show blockdev disks report in Linux
Oneliner to cleanup spool mails for each user in Linux
Generate a random string in Linux
Make find command stop after the first match with -quit
Working with hardware in Linux
Find your shell in Linux
grep recursively in hidden files and folders
Change passwords without interactive prompt in Linux
Show and change password settings for user in Linux
OOM killer in Linux
Get an overview of current useradd settings in Linux
sort data in tabular format with sort with -k option
find with -ok option - an -exec with prompt alternative
Kill all processes with a given partial name in Linux
find with size
Remove a user from a group in Linux
adduser vs useradd in Linux
Cache sudo user password timeout
sort
Linux Reader - access to alternative file systems from Windows
Limit locate output results
Make PATH variable human readable
Obtain information about locate database
Remove blank lines from file with grep
Interrupt
Find all zero-byte files in a path
mandb
Show the first 10 root folders by size
Purge logs within specified period of time from a directory with find in Linux
Red Hat Certified System Administrator (RHCSA) exam
xargs
Redirect output of a command to another terminal in Linux
How to get current week number and other details with date in Linux
tee
How to unzip a multipart (spanned) ZIP on Linux
Get total size of found files with find and du
man pages sections structure
Commands to clear the history in Linux bash shell
Linux
Get nameservers with host command
unzip to specific directory in Linux
zerotier-cli basic commands
Get IP address from console
Do not wrap lines in string encoded with base64 command
Release models of Linux distributions
umask
Understanding Linux processes, jobs and threads
Special symbols with sudo in bash
Understanding network device names in Linux
shuf
Common Linux network tools
Test SMTP server with swaks
Expiring the Linux user account
grep - list filenames that contain the pattern without showing matching files
ps
findmnt - shows all mounts
tar with progress
Set your favorite CLI text editor in Linux
Show non-printable characters in cat
view
grep -C5 - a combination between -A5 and -B5
Using at to schedule tasks
Prompt for confirmation when removing files with rm
find with exec
What process is listening on port 14777?
Grepping unneded lines from file
Example of using find with printf
What is time sharing
date
See properties and not contents of a directory with ls
Colorized grep
Delete bash history for current session only
rm
mkdir
Using extended grep
hostname
Check if a certain user has sudo access
man
which
w
uptime
uname
Generate a fingerprint for host and IPs to compare values from known_hosts
touch
Output passwd file into beautiful readable format
Another description of file system hierarchy
grep - escaping for special characters
Use tldr to get more help in Linux
Get information about the shell in Linux
clear in Linux
Listing files with full timestamps using ls in Linux
Find files modified last 30 days
Kernel Space and User Space in Linux
What is the Linux shell
Linux shell types
Linux basic commands
More Linux commands
chage
Linux add swap space oneliner
Show processes in parent/child relationship in Linux
touch a file with specified date in Linux
Drop cache in Linux
Get rid of the first header line with tail
Order to resolve the domain in Linux (hosts file or DNS)
Deep search with yum (search for files)
Silent mode in grep
Archive all directory logs except today with find and gzip
debugfs basic usage in Linux
Basic work with LVM in Linux
initramfs decompression in Linux
Boot Linux system into the state when the initramfs is loaded
NFS
NFS Server/Client configuration on Linux
Several methods to write ISO to flash drive
Show file descriptors in Linux
Changing the priority by modifying the nice value in top in Linux
Types of init systems in Linux
Show Samba shares on Linux
Update library cache in Linux
Disable a CPU in Linux
Pin a process to specific CPU using taskset in Linux
Managing dirty memory in Linux
List sockets in Linux
Search for a whole word with grep in Linux
Profiling CPU cache in Linux
Profiling memory leaks in Linux
View first bytes on a storage in Linux
Configuring iSCSI storage in Linux
Print partitions with use percentage greater than 20 in Linux
ACLs in Linux
Use ACLs in Linux
SUID in Linux
SGID in Linux
Sticky bit in Linux
Overview of Linux signals - man page
Over 300GB logs size due to "AER PCIe Bus" errors
Run Linux processes with different runtime policy
ufw basic usage
xargs with -I option
Make file immutable in Linux
KDUMP in RHEL/CentOS installation
Convert to lower case with tr
Show current process namespaces
Get the number of threads for a running process in Linux
passwd shadow group files structure
Create a temporary files in scripts
Put a process in new UTS namespace
Pseudo file systems in Linux
Put bash process in new other namespaces
Download manager which monitors clipboard
Linux kernel modules tools
woeusb - burn Windows ISO to flash from Linux
Listing devices in Linux
View kernel messages in Linux
List all namespaces in Linux
Apache Tomcat basics in Linux
Linux network commands
Types of Linux namespaces
nsenter - alternative to docker exec in Linux
Init runlevels
What is a Linux distribution
Linux boot process
Most used Desktop Environments
Enumerate fields for local credentials databases
Lock user password
Copy directory and preserve all permissions in Linux
Run the OOM adjustments on all php-fpm childs
Find files and directories with nouser and nogroup
Installing C compiler on Linux
Scan for writable directories with find
Get help in Linux
Delete a file from tar archive
Expire user password and force reset at next login in Linux
Open file with less pager - scrolled to the end
Linux file types
Search in specific sections with apropos in Linux
Prevent ssh from disconnecting on client side
Short introduction about pinfo documentation pages in Linux
Show memory hardware information
Analyze file metadata with file command
stat - another way to display useful details about the file in Linux
Test the ip and port with curl if telnet and netcat are not installed in Linux
7 Linux commands for beginners
mail command in Linux - send email in cli
apg - a cli password generator
Linux find not operator
diff most used invocations
lsblk
Linux kernel namespacing
Ignore case in searches when using less
Linux kernel Control Groups (cgroups)
What are Linux capabiities
Add the permissions for setuid, setgid and sticky bit on directory in Linux
Match whole words when searching with grep in Linux
readlink - show the path of the soft link
OpenSSH - generate public key from the private key
What is a kernel system call
Find files with special permissons in Linux