{"id":111925,"date":"2023-02-16T09:00:06","date_gmt":"2023-02-16T03:30:06","guid":{"rendered":"https:\/\/data-flair.training\/blogs\/?p=111925"},"modified":"2023-02-16T09:33:48","modified_gmt":"2023-02-16T04:03:48","slug":"input-output-redirection-in-linux","status":"publish","type":"post","link":"https:\/\/data-flair.training\/blogs\/input-output-redirection-in-linux\/","title":{"rendered":"Input Output Redirection in Linux"},"content":{"rendered":"

Input Output Redirection in Linux is one of the most interesting and important topics, it is this feature that allows you to redirect the input and\/or output of commands. In this article, you will learn all about the redirection of output and input in Linux-based operating systems. So pay attention, grab a snack if you need, and read right till the end.<\/p>\n

What is Input Output Redirection in Linux?<\/h3>\n

First of all, I\/O is the abbreviation for input\/output. In Linux-based operating systems, I\/O redirection is the ability of the operating system that allows us to change the STDIN (standard input) and STDOUT (standard output) while executing commands in the terminal.<\/p>\n

We all know that the STDIN device is your keyboard and the STDOUT device is your screen – at least for the terminal. The term redirection in computer language refers to the way from where commands read input to where commands send output.<\/p>\n

There are hundreds of shell commands, and every single one of them does one of the following – take input, give output or do both. With the help of the special redirection characters, we can redirect these input and output functionalities.<\/p>\n

Let us understand this better with an example. Say we run any arbitrary command in the terminal that will print the output on the terminal screen. But, we don\u2019t want the output printed on the terminal, instead, we
\nwant to save it into a file, using the redirection operator we can do exactly that. To sum up in one line, redirecting simply means diverting the input or output.<\/p>\n

Similarly, if we have another random command that needs to be given an input. But instead of giving the input directly, we want it to be taken from a specific file called \u201cfile.txt\u201d. To do the same, we simply make use of the redirecting operator. In this article, we will look at how to make use of it in multiple ways to redirect input and output.<\/p>\n

Linux I\/O Redirection Terminologies<\/h3>\n

Before we proceed further and look at how to use the redirection operator, let us familiarize ourselves with some terminology of the standard streams of the input\/output redirection.<\/p>\n

1. STDIN<\/strong><\/p>\n

STDIN stands for standard input. The bash shell takes input from the STDIN. The standard input stream is numbered as stdin(0). It is connected to the keyboard.<\/p>\n

2. STDOUT<\/strong><\/p>\n

STDOUT stands for standard output. The bash shell sends output to the STDOUT. The standard output stream is numbered as stdout(1). It is connected to the screen.<\/p>\n

3. STDERR<\/strong><\/p>\n

STDERR stands for standard error. The bash shell sends the error messages to STDERR. The standard error stream is numbered as stderr(2). It is connected to the screen.<\/p>\n

These are the 3 streams that come into the picture when we talk about input\/output redirection.<\/p>\n

Types of redirection operators in Linux<\/h3>\n

Before we look at how to use the redirection operator is important to understand how to combine the redirection operator to perform different actions.<\/p>\n

1. Overwrite<\/p>\n