How to Pipe or Redirect Output to Another Command
Introduction
In PowerShell, the pipe is a way to take the output of one command and pipe or redirect it into another command. This is similar to the concept of input/output (I/O) redirection in Unix and Linux. The pipe character is the vertical bar or | symbol located on your keyboard above the backslash character.
Examples
For example, you can use the Get-Process cmdlet to get a list of all running processes on a computer. But what if you only want to see a list of processes that are using more than 500 MB of memory? You could use the Where-Object cmdlet to filter the output of Get-Process like this:
Get-Process | Where-Object {$_.WorkingSet -gt 524288000}
This command would get a list of all processes and then pipe that output into Where-Object, which would filter the output based on the condition that WorkingSet is greater than 524288000 (500 MB).
Below is the output if we execute above script.
You can also use PowerShell pipes with external commands. For example, let’s say you want to use the findstr command to search for a string in a file. But instead of searching through every file in a directory, you just want to search through files with a .ps1 extension.
You can use PowerShell’s Get-ChildItem cmdlet to get a list of all .ps1 files in a directory and then pipe that output into findstr like this:
Get-ChildItem *.ps1 | findstr "test"
This command would first get a list of all .ps1 files and then pipe that output into findstr, which would search for the specified string.
Below is the output if we execute above script.
Conclusion
Piping is a powerful way to take the output of one command and use it as input for another command. In PowerShell, the pipe character is |. This article showed how you can use pipes with both built-in PowerShell cmdlets and external commands.