LINUX COMMANDS

This category covers topics including various linux command line utilities and its uses.

Linux ss Tool to Identify Sockets / Network Connections with Examples

ss tnap6

ss is part of the iproute2 (utilities for controlling TCP/IP networking and traffic) package. iproute2 is intended to replace an entire suite of standard Unix networking tools (often called "net-tools") that were previously used for the tasks of configuring network [...]

Adrian Dinu 12:04 pm

Colourful ! Systemd vs Init Cheatsheet for Linux

systemd is the new init system, starting with Fedora and now adopted in many distributions like RedHat, Suse and Centos. Historically, most of us have been using traditional SysV init scripts normally residing in /etc/rc.d/init.d/. These scripts invoke a daemon [...]

Bobbin Zachariah 10:38 am

Systemctl Commands to Manage Systemd Service in Linux

hostnamectl

Systemd is new service manager for Linux. It is a replacement for init system and can manage system startup and services. It starts up and supervises the entire system. In the article we are using centos 7.0 installed with systemd 216 [...]

Raghu 9:29 am

8 Options to Trace/Debug Programs using Linux strace Command

Relative Timestamp

The strace is the tool that helps in debugging issues by tracing system calls executed by a program. It is handy when you want to see how the program interacts with the operating system, like what system calls are executed [...]

Raghu 12:03 pm

How to Change Hostname in RHEL / CentOS 7.0

You have probably needed to change the hostname of your CentOS 7 install for one reason or the other. Changing the hostname in CentOS 7 is now much simpler than ever. If you are ready open up your terminal and [...]

Allan Mbugua 9:12 am

Linux Systemd - Start/Stop/Restart Services in RHEL / CentOS 7

systemctl-enable

One of the major changes in RHEL  / CentOS 7.0 is the swtich to systemd, a system and service manager, that replaces SysV and Upstart used in previous releases of Red Hat Enterprise Linux. systemd is compatible with SysV and [...]

Adrian Dinu 8:35 am

A Pocket Guide for Linux ssh Command with Examples

X11 forwarding

If you have been in the IT world for quite some time you probably have heard about SSH, how great a tool it is and all its cool security features. In this tutorial you will learn how to use SSH [...]

Bobbin Zachariah 9:16 pm

How to Merge Directory Trees in Linux using cp Command

Remove original directories

How to merge two directory trees with similar layout into a third directory?. Let us consider the following example to understand the problem. Suppose two directories dir1 and dir2 have 3 sub-directories a, b and c in each of them. [...]

Raghu 6:21 am

Linux slabtop command - Display Kernel Slab Cache Information

Sort by cache utilization 02

The Linux kernel needs to allocate memory for temporary objects such as task or device structures and inodes. The caching memory allocator manages caches of these types of objects. The modern Linux kernel implements this caching memory allocator to hold [...]

Raghu 9:09 am

Linux chpasswd Command - Change Passwords in Bulk Mode

Help with command chpasswd

Creating users and managing passwords is one of the primary responsibilities of a system administrator. A good policy requires modification of passwords on regular intervals. But changing the passwords for a number of users with passwd command becomes difficult. In [...]

Raghu 3:00 am

Advanced Directory Navigations Tips and Tricks in Linux

directory navigation

Directory navigation is one of the most basic concepts when it comes to understanding any command line system. Although it's not a very difficult thing to understand when it comes to Linux, there are certain tips and tricks that can [...]

Himanshu Arora 3:00 am

Lsblk - Command to List Block Device in Linux

lsblk SCSI devices

Lsblk command in linux is used to list information about all available block devices, however, it does not list information about RAM disks. Examples of block devices are a hard disk, flash drives, CD-ROM e.t.c Install lsblk The command lsblk [...]

Bobbin Zachariah 6:45 am

How to Use "Script" Command To Record Linux Terminal Session

Script with notification

This script command is very helpful for system admin. If any problem occurs to the system, it is very difficult to find what command was executed previously. Hence, system admin knows the importance of this script command. Sometimes you are on [...]

Pungki Arianto 3:00 am

How to use IP Command in Linux with Examples

Net tools vs Iproute2

The linux ip command is similar to ifconfig, but more powerful and is intended to be a replacement for it. With ip you have the advantage of performing several network administration tasks with only one command. ifconfig is one of the [...]

Bobbin Zachariah 3:00 am