11.3 Using Host Name
11.3.1 Setting Host Name
In the Raspberry Pi system, the name of the system itself is called host name. This host name has the function of refering to the Raspberry Pi system itself in the local network. Therefore, when another system in the same network communicates with the Raspberry Pi system, the host name can be used instead of the IP address assigned to the Raspberry Pi system.
11.2.2 Setting Assignment Method of IP Address
Generally, in the way that a computer is assigned an IP address in a network, there are “automatic IP assignment” and “static IP assignment”.
If the DHCP server is set to “automatic IP address assignment”, it has the function of automatically assigning IP addresses to individual computers connected to the internal network managed by the server. Normally, IP address is automatically assigned one by one in the order that each computer is connected to the network. In this way, if the current IP address is assigned to 192.168.0.100, the next connected computer is given an IP address of 192.168.0.101.
11.2 Information for Network Setting
11.2.1 Information for Network Setting
In the Raspberry Pi system, the basic settings for the network are stored in “/etc/network/interfaces” file.
When you check the file contents on the Terminal screen, the following is included.
11.1.2 “ifconfig” Command – Verify Network Status & IP Address
The “ifconfig” command is used on the Raspberry Pi system to check the current network connection status, to start a new network connection, or to stop normal working network.
[Command Format]
ifconfig [display-option] [interface] [operation option]
11.1 Network Overview
11.1.1 Network Connection and IP Address
The IP address must be specified in order for a computer to be connected to the network. This IP address is always used when communicating with other computers on the network. The Raspberry Pi system is also assigned an IP address when connected to the network.
Chapter 11 Network Management
Chapter’s Main Topics
Here, we will look at how to inquire the network information in the Raspberry Pi system and how to configure various setting item to connect to the network through a desired manner.
It includes descriptions on the following topics:
■ Network overview
■ Network setting information
■ Using hostname
■ Wired network connection
■ Wireless network connection
■ Setting static ip
■ Activation and stop of network
■ Bluetooth setting and connection
10.9.4 “uniq” Command
This command performs the function of removing adjacent redundant data when reading data from the input or exporting the data to the output.
[Command Format]
uniq [option] [input] [output]
[Command Overview]
■ This removes adjacent redundant row data from input or output.
■ User privilege — Normal user.
10.9.3 “sort” Command
This command sorts the data in the specified file according to certain rule and then exports them to standard output.
[Command Format]
sort [option] [directory/file]
[Command Overview]
■ This sorts the data in the specified file.
■ User privilege — Normal user.
10.9.2 “wc” Command
This command counts and returns the number of line, word, and byte in the specified file.
[Command Format]
wc [option] [directory/file]
[Command Overview]
■ This calculates and reports the number of line, word, and byte in the specified file.
■ User privilege — Normal user.
10.9 Commands Related to Data Manipulation
10.9.1 “awk” Command
The “awk” command reads the specified file, finds the line that has a value matching the specified pattern, and performs the specified operation if the pattern matches. Here, the operation means a field manipulation in a line or an arithmetic operation using a field value. The name “awk” comes from the names of three people who developed it, Aho, Weinberger, and Kernighan.
Awk is a programming language with features such as Shell programming, BC, and the C programming language. It works perfectly with BC, and field variables with names like Shell arguments $1, $2, and $3 can be used on each input line. It also has a printing and control operator similar to the C language.