To redirect all requests from one domain to another in Nginx, you can add the following code to your Nginx configuration file: server { listen 80; server_name olddomain.com; return 301 $scheme://newdomain.com$request_uri; } This code listens on port 80 and checks the hostname of incoming requests. If the hostname is “olddomain.com”, it returns a 301 redirect … Read more

To unpack a .tgz file on a Linux system, use the following command: tar -xvzf filename.tgz x option is to extract the archive. v option is for verbose output, it shows the progress of the unpacking process. z option is to unpack the archive with gzip. f option is to specify the archive file name. … Read more

To reload or restart the dhcpd server on OpenBSD, use the following command: # rcctl restart dhcpd To stop the dhcpd server, use the following command: # rcctl stop dhcpd

Installing KVM on RHEL/CentOS 6.x involves the following steps: Verify hardware virtualization support: Make sure that your hardware supports virtualization. You can check this by running the following command: grep -E ‘vmx|svm’ /proc/cpuinfo Install KVM packages: The KVM packages can be installed using the “yum” package manager. Run the following command in your terminal: yum … Read more

To upgrade CentOS 6 to version 6.5, follow these steps: Backup your data: Before proceeding with the upgrade, it’s always a good idea to backup your data. This way, you can restore your system if something goes wrong during the upgrade process. Update existing packages: Before upgrading the CentOS version, you should update all existing … Read more

To install Go programming language on Mac OS X, you have several options: Homebrew: This is a package manager for Mac OS X that makes it easy to install and manage software. To install Go using Homebrew, run the following command in your terminal: brew install go Binary Installer: You can also download the binary … Read more

To allow all but block certain POST request URLs for selected spammer IP addresses/CIDR in Nginx, you can use the following configuration in your Nginx server block: location / { if ($request_method = POST) { set $block 0; # block POST requests to /spammer if ($uri = /spammer) { set $block 1; } # block … Read more

In an SSH shell command, “–” (double dash) is used as a command line option separator. It separates options from positional parameters and is used to indicate that no further options are to be parsed. For example, consider the following command: ssh user@host — ls -l Here, the “–” is used to separate the options … Read more

To reinstall MySQL v5.x on Linux, you can follow these steps: Stop the MySQL service: sudo systemctl stop mysqld Remove the existing MySQL installation: sudo yum remove mysql Remove the MySQL data directory: sudo rm -rf /var/lib/mysql Download the MySQL repository package: wget https://repo.mysql.com/mysql57-community-release-el7-11.noarch.rpm Install the MySQL repository package: sudo yum localinstall mysql57-community-release-el7-11.noarch.rpm Install MySQL: … Read more

Wget is a network downloader utility that is not included by default on macOS. However, you can install it using a package manager like Homebrew. Here are the steps to install wget on macOS using Homebrew: Install Homebrew if you don’t already have it installed. You can install it by running the following command in … Read more