How to Switch Command Output to File on Windows

How to Use Redirection Operators in PowerShell

PowerShell is an advanced command-line interface that you can use to run various commands and scripts in Windows. PowerShell has the same redirect operators as Command Prompt, but it also has some additional operators that are more flexible and powerful.

Here’s a list of redirect operators you can use in PowerShell:

• >: This operator is used to redirect the command output to a new file. If the file already exists, then its contents will be overwritten by the command output. This operator simply switches the output referred to as “stream 1” or “output stream”, which is the normal output displayed on the screen.
• >>: This operator is used to redirect command output to an existing file. If the file does not already exist, a new file will be created. The output of the command will be appended to the end of the file, without deleting the previous contents. This operator simply switches the output stream.
• <: This operator is used to take input from a file and pass it to the command. This is useful if you want to run a command with parameters stored in a text file.
• |: This operator is used to correlate the output of one command with the input of another command. This is referred to as pipelining, and it allows you to create a series of interdependent commands.
• 2>: This operator is used to redirect an output referred to as “stream 2” or “error stream”, which is an output containing an error message displayed on the screen.
• 2>>: This operator is used to redirect stream errors to existing files. If the file does not already exist, a new file will be created. The error stream output will be appended to the end of the file, without removing the previous contents.
• 3>: This operator is used to redirect an output referred to as “stream 3” or “warning stream”, which is an output containing a warning message displayed on the screen.
• 3>>: This operator is used to redirect the alert stream to an existing file. If the file does not already exist, a new file will be created. The warning stream output will be appended to the end of the file, without removing the previous contents.
• 4>: This operator is used to redirect output referred to as “stream 4” or “verbose stream”, which is output containing additional information displayed on the screen if you use the -Verbose parameter in commands.
• 4>>: This operator is used to redirect the verbose stream to an existing file. If the file does not already exist, a new file will be created. The output of the verbose stream will be appended to the end of the file, without deleting the previous contents.
• 5>: This operator is used to redirect output referred to as “stream 5” or “debug stream”, which is output containing debug information displayed on the screen if you use the -Debug parameter in the command.
• 5>>: This operator is used to redirect the debug stream to an existing file. If the file doesn’t already exist, this command adds the debug output of the stream to the end of the file, without removing the previous contents.

You can use these redirect operators simultaneously to switch output from different streams to different files. For example, if you want to run the “Get-Process” command to see a list of processes running on your system, and redirect the normal output to the “process.txt” file, the error output to the “error.txt” file, and the verbose output to the “verbose.txt” file, then you can type the following command:

Get-Process -Verbose > process.txt 2> error.txt 4> verbose.txt

This command will create three new files in the current directory, and write the output of each stream to the corresponding file. If the files already exist, then their contents will be overwritten by the command output.

You can also use special redirect operators called “tee-object” to redirect command output to a file while displaying it on the screen. This is useful if you want to save the command output for future reference, but also want to see it live.

To use tee-object, you need to add the symbol “|” after the command you want to execute, followed by the word “tee” and the name of the destination file. For example, if you want to run the “Get-Date” command to see the current date and time, and redirect the output to the “date.txt” file while displaying it on the screen, then you can type the following command:

Get-Date | Tee date.txt

This command will create a new file named date.txt in the current directory, and write the output of the Get-Date command into it. The output will also be displayed on the screen.