How do I redirect the output to null?
How do I redirect the output to 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.
What is null output?
The null device is typically used for disposing of unwanted output streams of a process, or as a convenient empty file for input streams. This is usually done by redirection. The /dev/null device is a special file, not a directory, so one cannot move a whole file or directory into it with the Unix mv command.
Does Shell not print output?
To silence the output of a command, we redirect either stdout or stderr — or both — to /dev/null….3. Silencing Output
- 3.1. Standard Output. To silence non-error output, we redirect stdout to /dev/null: command 1> /dev/null.
- 3.2. Standard Error.
- 3.3. All Output.
Is writing to Dev null faster?
If a script or program produces lots of output, generally, a reduction of the amount of output will make things run faster. The most radical reduction often seen at the command line is a redirection to /dev/null . However, this can be done in various ways with rather varying results.
Can you read from Dev null?
You write to /dev/null every time you use it in a command such as touch file 2> /dev/null. You read from /dev/null every time you empty an existing file using a command such as cat /dev/null > bigfile or just > bigfile. Because of the file’s nature, you can’t change it in any way; you can only use it.
How to redirect 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.
How are input and output redirected in Unix?
In this chapter, we will discuss in detail about the Shell input/output redirections. Most Unix system commands take input from your terminal and send the resulting output back to your terminal. A command normally reads its input from the standard input, which happens to be your terminal by default.
How do I redirect a command to discard the output?
In such cases, you can discard the output by redirecting it to the file /dev/null − Here command is the name of the command you want to execute. The file /dev/null is a special file that automatically discards all its input. To discard both output of a command and its error output, use standard redirection to redirect STDERR to STDOUT −
What does / dev / null do in Linux?
/dev/null is nothing but a special file that discards all data written to it. The length of the null device is always zero. In this example, first, send output of date command to the screen and later to the /dev/null i.e. discards date command output: