What Is The Meaning Of 2 >& 1?

What is 2 and1 batch file?

txt 2>&1 to merge Standard Output and Standard Error and redirect them together to a single file.

This could be useful when prompting for input even if the batch file’s output is being redirected to a file.

Use 1>&2 to send text to Standard Error.

This can be useful for error messages..

What does >& mean in bash?

3. >& is the syntax used by csh and tcsh to redirect both stdout and stderr. That’s probably why bash accepts it. –

What does stdout mean?

Standard OutputStandard output, sometimes abbreviated stdout, refers to the standardized streams of data that are produced by command line programs (i.e., all-text mode programs) in Linux and other Unix-like operating systems.

What is the meaning of 2 &1 in Linux?

“You use &1 to reference the value of the file descriptor 1 (stdout). So when you use 2>&1 you are basically saying “Redirect the stderr to the same place we are redirecting the stdout”. And that’s why we can do something like this to redirect both stdout and stderr to the same place:”

What is 2 NUL?

The 2>NUL redirection suppresses error output, but has no effect on standard output messages. The usual way to redirect both is >NUL 2>&1 , and you should use this form when redirecting both to a file.

How do I redirect stderr?

Redirecting stderr to stdout When saving the program’s output to a file, it is quite common to redirect stderr to stdout so that you can have everything in a single file. > file redirect the stdout to file , and 2>&1 redirect the stderr to the current location of stdout . The order of redirection is important.

What does >> mean in batch file?

It means “all the parameters in the command line”. … You typically use it when you want to call some other program or script and pass the same arguments that were passed to your script.

How do I pass from one command to another in Windows?

In interactive mode, you need type echo on and press Enter to exit. If you are sure that loop only run once (i.e. output of (‘xxx’) is single line), then you can direct append echo on in the command.

What does &> mean in bash?

Redirecting Standard Output&> is a bash extension and not de jure standard. … From Bash Reference Manual -> 3.6. 4 Redirecting Standard Output and Standard Error: This construct allows both the standard output (file descriptor 1) and the standard error output (file descriptor 2) to be redirected to the file whose name is the expansion of word.

Which command will find a file without showing permission denied messages?

Find a file without showing “Permission Denied” messages When find tries to search a directory or file that you do not have permission to read the message “Permission Denied” will be output to the screen. The 2>/dev/null option sends these messages to /dev/null so that the found files are easily viewed.

What does the 2 &1 at the end of the following command mean?

2 refers to the second file descriptor of the process, i.e. stderr . … &1 means the target of the redirection should be the same location as the first file descriptor, i.e. stdout . So > /dev/null 2>&1 first redirects stdout to /dev/null and then redirects stderr there as well.

What does 2 mean in bash?

File descriptor 2 represents standard error. (other special file descriptors include 0 for standard input and 1 for standard output). 2> /dev/null means to redirect standard error to /dev/null . /dev/null is a special device that discards everything that is written to it.

How do you tell which shell you are using?

How to check which shell am I using: Use the following Linux or Unix commands: ps -p $$ – Display your current shell name reliably. echo “$SHELL” – Display the shell for the current user but not necessarily the shell that is running at the movement.

How do you append stdout and stderr to a file?

There are (at least) two ways of achieving this: Either use this construct: cmd >>file. txt 2>&1 where >> file appends the output to the file and 2>&1 redirects the stderr to stdout .

What does >/ dev null 2 >& 1 mean?

>> /dev/null redirects standard output ( stdout ) to /dev/null , which discards it. … 2>&1 redirects standard error ( 2 ) to standard output ( 1 ), which then discards it as well since standard output has already been redirected.