The manual page and help for the ipcalc Linux command. The ipcalc command can be used to find out information about IP addresses and subnet masks. Based on the specified IP address or subnet mask, the ipcalc command determines the class of the IP address, the network ID, the subnet mask, the number of free IP addresses, the broadcast IP address of the network, and the first/last usable IP address. addresses.
To use the command on Debian/Ubuntu systems, the ipcalc package must be installed.

The jq Linux command manual page and help. The jq command is a utility for parsing, processing, and manipulating JSON files.

Manual page and help for the ifdown Linux command. The ifdown command disables the specified network interface.

The manual page and help for the ifup Linux command. The ifup command enables the specified network interface.

Manual page and help for the id Linux command. The id command provides information about the given user or about the person running the program if no user is specified.

The monit Linux command manual page and help. Monit is a utility for managing and monitoring processes, programs, files, directories and file systems on Unix/Linux systems. Monit performs automatic maintenance and repair and can perform meaningful cause-effect actions in error situations. For example, Monit can start a process if it is not running, restart a process if it is not responding, and kill a process if it is using too many resources.

Help for the acme.sh Linux command. The acme.sh command is a shell script-based ACME client that can be used to request SSL certificates for websites. The program is very flexible and supports several CA (Certificate Authorities), including Let's Encrypt, which also issues free certificates, which makes it very popular.

The manual page and help for the resolvectl Linux command. The resolvectl command resolves domain names, IPv4 and IPv6 addresses, DNS resource records, and services.

The manual page and help for the paste Linux command. The paste command concatenates lines of files.

The manual page and help for the ncdu Linux command. ncdu (NCurses Disk Usage) is an interactive (NCurses-based) disk usage checking program running in a terminal. When the program is started, it first detects, calculates, and then lists the subdirectories and files of the given directory and shows their sizes. In the case of libraries, it naturally shows the recursively summed sizes. A very effective interactive alternative to the well-known du command. To use the program on Debian / Ubuntu systems, the ncdu package must be installed.