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Can dev Null be read?
To begin, /dev/null is a special file called the null device in Unix systems. Colloquially it is also called the bit-bucket or the blackhole because it immediately discards anything written to it and only returns an end-of-file EOF when read.
What is dev Null as a service?
In Unix-like operating systems, /dev/null or the null device is a special file that discards all data written to it but reports that the write operation succeeded. It provides no data to any process that reads from it, yielding EOF immediately.
What is tail Dev null?
5. @Sokre – The tail -f /dev/null is a common idiom for keeping a container alive indefinitely if the “real” command isn’t long-lived. – Oliver Charlesworth. May 8 ’17 at 9:07. Just to add some detail to tail -f /dev/null .
How to send output to / dev / null?
You can send output to /dev/null, by using command >/dev/null syntax. However, this will not work when command will use the standard error (FD # 2). So you need to modify >/dev/null as follows to redirect both output and errors to /dev/null. Syntax to redirect error and output messages to /dev/null
What does redirecting to / dev / null mean?
This is because of using > /dev/null 2>&1 will redirect all your command output (both stdout and stderr) to /dev/null, meaning no outputs are printed to the terminal. To understand this easily, write it out explicitly. Below is an example command that tries to remove a nonexisting file (to simulate an error)
Where does the data go in / dev / null?
Before diving deep into the usage of /dev/null, we have to have a clear grasp of the stdout and stderr data stream. Check out this in-depth guide on stdin, stderr, and stdout. Let’s have a quick refresh. Whenever any command-line utility is run, it generates two outputs. The output goes to stdout and the error (if generated) goes to stderr.
How does / dev / null work in Linux?
As far as programs running in the system are concerned, these virtual devices act as if they are real files. Tools can request and feed data from these sources. The data is generated by the OS instead of reading them from a disk. One such example is /dev/null.