The “If-Modified-Since” header is used in an HTTP request to ask the server to return the requested resource only if it has been modified since the specified date and time. This allows the client to avoid downloading a resource that hasn’t changed. You can use the curl command with the -z or –time-cond option to … Read more

You can use the following line of code in a bash script to determine the directory in which the script is stored: SCRIPT_DIR=”$(cd “$(dirname “$0″)” && pwd)” Here’s how it works: dirname “$0” returns the directory component of the script’s file path. cd “$(dirname “$0″)” && pwd changes to the directory and prints the absolute … Read more

You can use the sed command to find and replace the whole line using a regular expression (regex). The basic syntax is as follows: sed ‘s/<regex to match>/<replacement string>/g’ <input file> Where <regex to match> is the pattern you want to search for, and <replacement string> is the string you want to replace it with. … Read more

Planet Venus is a software that allows you to combine multiple RSS feeds into a single feed. It can be used on Debian/Ubuntu systems to set up a custom feed aggregator. Here is an example of how to install and set up Planet Venus on a Debian/Ubuntu system: Install Planet Venus: sudo apt update sudo … Read more

You can split a string into an array in bash using the IFS (Internal Field Separator) variable and parameter expansion. Here is an example of how to split a string into an array: string=”one two three four” IFS=’ ‘ read -ra arr <<< “$string” for i in “${arr[@]}”; do echo “$i” done In this example, … Read more

You can extract the filename and extension from a file path in bash using parameter expansion and string manipulation. Here are a few examples of how to extract the filename and extension: Extract the filename and extension using parameter expansion: path=”/path/to/file.ext” filename=”${path##*/}” extension=”${filename##*.}” echo “Filename: $filename” echo “Extension: $extension” Extract the filename and extension using … Read more

You can test the internet connection speed from the command line using the speedtest-cli tool. This tool can be installed on Linux or Unix systems using the package manager for your distribution, such as apt, yum, or homebrew. Here is an example of how to install and use speedtest-cli on a Debian/Ubuntu system: Install speedtest-cli: … Read more

To install the Cherokee web server on Debian/Ubuntu Linux, you can follow these steps: Add the Cherokee repository to your system’s repository list: echo “deb http://www.cherokee-project.com/deb/ $distro $arch” | sudo tee /etc/apt/sources.list.d/cherokee.list where $distro is your Debian or Ubuntu distribution (e.g. bionic, focal, xenial, etc.) and $arch is your system architecture (e.g. amd64, i386, etc.). … Read more

The /tmp directory is a temporary file storage location that is world-writable. To increase the security of the system, you can mount /tmp with the nodev, nosuid, and noexec options. These options have the following meanings: nodev: This option disables the ability to access device files on the file system. nosuid: This option disables the … Read more

To configure a firewall using Shorewall under Red Hat Enterprise Linux (RHEL) / CentOS, you can follow these steps: Install Shorewall: yum install shorewall Start the firewall and enable it to start at boot: systemctl start shorewall systemctl enable shorewall Configure the firewall rules: Shorewall rules are stored in the following files: /etc/shorewall/policy: contains the … Read more