macOS, OpenBSD and GNU/Linux are great operating systems. They are inspired by UNIX and are stable. These three operating systems have many things in common, including many of the GNU tools. In this article, we will discuss the key differences between these operating systems. macOS is based on NetBSD Unix (Darwin). It is open-source. Apple adopted this in the early 2000s. However, some parts of … [Read more...]
Using the tee Command and Difference With cat Command
The tee command converts a standard output into a standard input and also can write this to files. So tee is practically only about writing to a file. The cat command is for reading (both input and files) and writing (with > and >>) to files. cat is a powerful and safe tool. tee is used in specific advanced complex cases. For the below function, you can not use … [Read more...]
Is chroot a Security Feature?
chroot stands for change root and is a function on Unix systems to change the root directory. It only affects the current process and its child processes. "chroot" itself can refer to both the chroot system call and the chroot utility. A program that has been "rooted" to a directory and has no open file descriptors outside the root virtual directory will no longer be able to access files outside … [Read more...]
How to Use pgrep and pkill Command
On unix-like OS, the pkill command sends a signal to the processes while the pgrep command searches for processes currently running on the system. Originally, the pkill was written for using with the Solaris 7 (1998). kill, killall, pkill, pgrep can be used on all the GNU/Linux OS, MacOS X and Linux shell on Windows 10. The kill signals HUP (1) reloads a process, KILL (9) kills a process, TERM … [Read more...]
List of Command Line Music Players For Mac, Linux
Tools which uses text based user interface (TUI) is our one favourite topic. Many music lover want lightweight yet music players with visualizer & settings. Here is a List of Command Line Music Players For Mac, Linux. For developmental purpose, who are new readers of this website - previously we talked about TUI on SSH, how to develop TUI applications and also discussed about few command line … [Read more...]
Fail2Ban Log Analysis Bash Script For Report Generation
Previously we gave some complicated commands to our readers who use Fail2Ban and needs some checking. Other way was using BadIPs for creation of graph. Fail2Ban log analysis bash script is for report generation as list of attacker IPs, banned, unbanned, password attempts sorted by date, country. We written this easy script using various commands and we think it is useful to any sysadmin to quickly … [Read more...]
Install GoAccess Real-Time Web Log Analyzer : Apache, Ubuntu
Previously we published GoAccess guides for Nginx and Nginx log with GeoIP. Here in this guide we will show how to install GoAccess real-time web log analyzer for Apache webserver running on Ubuntu and in case of Apache you need not to separately work on how to enable Apache log to have GeoIP enabled features. Apache default log itself a standard format. Install GoAccess Real-Time … [Read more...]
How To Configure OCSP Stapling On Apache 2.4+
Previously we talked about OCSP, OCSP Stapling and OCSP Stapling on Nginx. Now, we will configure OCSP Stapling In Apache 2.4 It is important to avoid some settings of OCSP Stapling on a production website as it can give errors like OCSP Response Expired or just in case of Nginx 502. Here is how to configure OCSP Stapling on Apache 2.4+ with full configuration. These are among TLS optimisazion. In … [Read more...]
How To Perform Security Audits On Ubuntu 16.04 (With Lynis)
Security audit in our case is am automatic technical assessment of our server and web applications in the context of security by performing security vulnerability scans, reviewing application and operating system access controls some softwares or scripts. At the ens, we will gather a software generated audit report. Here is how to perform security audits on Ubuntu 16.04 with Lynis and other tools … [Read more...]
Install, Configure Advanced Policy Firewall (AFP) On Ubuntu 16.04
If you are a new user, you should not follow this guide for production sever but follow our basic server setup guide and IPTables guide to configure your firewall. New users can follow this guide with test/development servers. Advanced Policy Firewall is an iptables based firewall. Here is how to install, configure Advanced Policy Firewall (AFP) on Ubuntu 16.04. It is essentially an interface to … [Read more...]
List Of Anti Malware For GNU/Linux Server
We noticed that we need to deliver guides around some known things which are possibly not known to the new users. Somehow, many we missed talking about them since the year 2010. Anti Malware is not a fully correct phrase for Linux but the meaning is obvious. Here is a usable list of Anti-malware for GNU/Linux server. Malware is a program that aims to disrupt the normal operation of a server. … [Read more...]