What are standard output and standard error?

What is /dev?

In the Linux file system, everything is a file or a directory. Even devices are accessed as files. Your hard drive partitions, Pen drive, speakers, for all of these, there exists a file from which these are accessed. Now to understand how devices are accessed as files, think of it in this way: what do we do with a file? We read data from it and write data to it. A device like a speaker can input data to produce sound, a hard disk can be used to read and write data, a printer takes the input to print files, etc. Files and devices are similar in this way...

What is /dev/null?

It is a virtual device, which has a special property: Any data written to /dev/null vanishes or disappears. Because of this characteristic, it is also called bitbucket or blackhole. Let us see a demonstration....

Usage of /dev/null

Since it discards anything written to it, you can move files to /dev/null to delete them. But this is not a widely used use case. It is mainly used to discard standard output and standard error from an output....

What are standard output and standard error?

The output of a Linux command contains two streams of data: standard output (stdout) and standard error (stderr0), while the standard output is the normal output if the command has no errors, the standard error is the error generated by the command. Output may contain both standard output and standard input. Example of stdout and stderr:...

How to access stderr and stdout?

Stdout and stderr are streams of data, both of which are treated as a file in Linux. If you wish to perform any action on these, you use a file descriptor that uniquely identifies the file stream. The file descriptor for stdout is 1 and for stderr is 2....

Conclusion

In this article we discussed `/dev/null’ in Linux is a virtual black hole where data disappears when written to it. It is commonly used to discard output and errors, making command execution cleaner. It can also be employed for secure file deletion and log file cleaning. Understanding its functionality allows for efficient command-line operations in Linux....