To turn on TCP SYN cookie protection in Linux, you need to modify the kernel parameters. You can do this by adding the following line to the /etc/sysctl.conf file: net.ipv4.tcp_syncookies = 1 After adding this line, run the following command to apply the changes: sysctl -p This will activate TCP SYN cookie protection, which helps … Read more

To block access to the URL wp-admin/wp-login.php for all IP addresses except one in nginx, you can use the following configuration in the server block for the website: location /wp-admin/wp-login.php { allow 192.168.1.100; deny all; } This configuration uses the location directive to specify the URL to be restricted. The allow directive allows access to … Read more

In awk, you can remove all blank spaces from a string or field using the gsub function. For example, to remove all blank spaces from the first field of each record in a file: awk ‘{gsub(/ /,””,$1); print}’ file.txt In this example, the gsub function replaces all occurrences of a space character (represented by / … Read more

In vim, you can jump back to your previous or last cursor position by using the ” (two single quotes) command. The ” command takes you to the position where your cursor was before your last jump. For example, if you are editing a file and you move the cursor to a different location, you … Read more

You can check if a directory exists in a shell script by using the if statement in combination with the test command or the [ command. For example, using the test command: if [ -d “/path/to/directory” ]; then echo “Directory exists” else echo “Directory does not exist” fi Using the [ command: if [ -d … Read more

To create a new file with the vim text editor, you can use the following command: vim filename Where filename is the name of the file you want to create. Once the vim editor is open, you can start typing the content of your file. To save the file, press the Esc key to enter … Read more

You can install Eclipse on Debian-based systems, such as Debian or Ubuntu, by using the following steps: Download the latest version of Eclipse from the official Eclipse website (https://www.eclipse.org/downloads/). Extract the downloaded archive to your preferred location using the following command: tar -zxvf eclipse-*.tar.gz Launch Eclipse by running the eclipse executable located in the extracted … Read more

When you run certain package management commands, such as apt-get autoremove or apt autoremove, you may receive a warning message that states “The following packages were automatically installed and are no longer required”. This warning message means that the package manager has identified packages that were installed as dependencies for other packages, but are no … Read more

In a Bash shell script, you can find the number of arguments passed to a function by using the $# special variable. The $# variable holds the number of arguments passed to the function. Here is an example of a simple function that prints the number of arguments passed to it: j find_arguments_count() { echo … Read more

To remove all files in a directory in a Unix-like system, you can use the following command: rm -rf directory_name The rm command is used to remove files or directories, and the -rf options are used to force the removal of the directory and its contents, including any files and subdirectories. Note: This command is … Read more