Gethostbyname() function in Python

Python Programming Language

Python programming language is one of the most used programming languages, as it is used widely in the field of software and data analysis, web development, etc. It is said to be a user-friendly programing language, as the syntax for it is very simple to write and easy to understand for a beginner programmer. Python programming language is rich in libraries that can be imported easily and used to perform many different operations. In the year 1989, Guido van Rossum is the one who introduced python programming language. It is also used in web applications; web applications like the Django and Flask frameworks are created using python. Compared to any programming language, the syntax in python is much easier.

Python programming language is most widely used language in today’s technology. Many colleges and institutions have introduced python in their syllabus so that the students need to learn python. The biggest advantage of the python programming language is that it has a good collection of libraries widely used in machine learning, web frameworks, test frameworks, multimedia, image processing, and many more applications. Python supports multiple programming paradigms, including object-oriented, imperative, functional, and procedural.

The gethostbyname() function, when given a host name, returns the host's IP address. While the host may resolve to several IPs from a specific location, gethostbyname() only provides the host's single IP.IPv4 is the format of the returned IP address.Thesocket.getaddrinfo() function can be used if the developer wants to resolve the hostname into IPv6 addresses or if both IPv4 and IPv6 addresses are required.

The hostent structure, which Windows Sockets allocates, is pointed to the thegethostbyname function. The outcomes of a successful search for the host indicated by the name parameter are contained in the hostentstructure. Only the IPv4 addresses will be returned if the host specified in the name parameter contains both IPv4 and IPv6 addresses. For the name parameter, the gethostbyname method can only return IPv4 addressesThegetaddrinfo function and associated addrinfo structure should be used if the host needs IPv4 and IPv6 addresses, or if IPv6 addresses are required.A variety of networking-related apps are available in Python.

As a method of communication with other users on your network, developers regularly use it. Therefore, the hostname in Python is needed for these communications. The name given to a device to identify it in a local network is called the hostname. In essence, the machines can communicate with one another within a network by using the hostname. 

Hostname

A device's hostname is a name or alias that is used to distinguish it from all other devices connected to a network node and may be unique. You can use this hostname, which can be completely different, to differentiate between several devices.

Hostnames are normally composed of ascii characters, but this might vary depending on the network.

In some circumstances, if the hostnames are changed forcibly, many devices may have the same hostname. Even though they have the same hostname, they could have different MAC addresses.

Get Hostname in Python

The hostname and IP address of a local machine can be discovered in a variety of ways. Here is a straightforward Python script to find the hostname and IP address. Using library - socket: The BSD socket interface is accessible through this module. It is supported by Python and is accessible on all current Unix systems, Windows, macOS, and presumably additional platforms.

Method 1:  With the help of platform module usage

The hostname and IP address of a local machine can be discovered in a variety of ways. Here is a straightforward Python script to find the hostname and IP address.

Using library - socket: The BSD socket interface is accessible through this module. It is supported by Python and is accessible on all current Unix systems, Windows, macOS, and presumably additional platforms.

Getting the Hostnames with the help of URL

We frequently need to access domain names using our existing URLs. Python offers many options for doing this. For instance, some of the methods include the use of other modules, Regex, string splitting, and urllib. Although all of these features are functional, we typically choose the urllib module the most. The urllib is part of the networking module and is available to us by default, which explains why. As a result, we do not need to add any additional lines of code to use the urllib module and its functionalities.

URL slicing In order to complete our work, we will use URL parsing. It is the responsibility of the URL parsing methods to either separate a URL string into its component parts or combine URL components into a URL string

Example:

import platform
print(platform.node())

Output:

SDCCTHGBSM444

Method 2: With the help of the socket module

Using socket programming, two nodes on a network can connect and communicate with one another. The other socket (node) reaches out to the first socket to establish a connection while the first socket listens on a certain port at an IP. The standard host name for the local computer is retrieved using the gethostname function.

Example:

import socket
print(socket.gethostname())

Output:

SDCCTHGBSM444

Gethostbyname( ) Function:

The gethostbyname() function, when given a host name, returns the host's IP address. While the host may resolve to several IPs from a specific location, gethostbyname() only provides the host's single IP.IPv4 is the format of the returned IP address. Thesocket.getaddrinfo() function can be used if the developer wants to resolve the hostname into IPv6 addresses or if both IPv4 and IPv6 addresses are required.

The hostent structure, which Windows Sockets allocates, is pointed to the thegethostbyname function. The outcomes of a successful search for the host indicated by the name parameter are contained in the hostentstructure. Only the IPv4 addresses will be returned if the host specified in the name parameter contains both IPv4 and IPv6 addresses. For the name parameter, the gethostbyname method can only return IPv4 addressesThegetaddrinfo function and associated addrinfo structure should be used if the host needs IPv4 and IPv6 addresses, or if IPv6 addresses are required.

If the name parameter corresponds to an empty string or if name is NULL, the string returned is identical to the string returned by a successful call to the gethostname function (the standard host name for the local computer).

If the string in the name parameter reflects a valid IPv4 address, the binary IPv4 address that corresponds to it is returned in the hostent structure. The IPv4 address is represented as a string in the hostent structure's h name member and as a binary number in the h addr list member. The gethostbyname function will fail and return WSANO DATA if the name parameter contains a string representation of an IPv6 address or an unrecognised IPv4 address.

The Winsock DLL allots memory from thread local storage for the hostent structure that the gethostbyname method returns. There is only one hostent structure allocated and used, regardless of how many times the gethostbyaddr or gethostbyname operations are called on the thread. The provided hostent structure needs to be moved to an application buffer if the gethostbyname or gethostbyaddr operations are to be called repeatedly on the same thread. If not, further gethostbyname or gethostbyaddr requests on the same thread will overwrite the value of the result. The Winsock DLL releases the internal memory it reserved for the returned hostent structure when the thread completes. It is impossible to translate an IP address string sent as a parameter to the gethostbyname function into a host name. An application can utilise the inetaddr function to convert an IPv4 address string to a binary IPv4 address, which can then be converted to a host name using the gethostbyaddr function.

Conclusion

A variety of networking-related apps are available in Python. As a method of communication with other users on your network, developers regularly use it. Therefore, the hostname in Python is needed for these communications. The name given to a device to identify it in a local network is called the hostname. In essence, the machines can communicate with one another within a network by using the hostname. 

The gethostbyname() function, when given a host name, returns the host's IP address. While the host may resolve to several IPs from a specific location, gethostbyname() only provides the host's single IP.IPv4 is the format of the returned IP address.

Thesocket.getaddrinfo() function can be used if the developer wants to resolve the hostname into IPv6 addresses or if both IPv4 and IPv6 addresses are required. The hostent structure, which Windows Sockets allocates, is pointed to the thegethostbyname function.