Pipelines

The pipeline is one of the most prominent features of PowerShell. The pipeline is used to send output from one command to another command as input.

Most of the output from a command is sent to what is known as standard output, often shortened to stdout.

Standard output

The term standard output is used because there are different kinds of output. Each of these different types of output is sent to a different stream, allowing each to be read separately. In PowerShell, the streams are Standard, Error, Warning, Verbose, Debug, and Information.

When assigning the output of a command to a variable, the assigned value is taken from the standard output (the output stream) of a command. For example, the following command assigns the data from the standard output to a variable:

$computerSystem = Get-CimInstance -ClassName Win32_ComputerSystem 

Non-standard output, such as Verbose, will not be assigned to the variable.

Non-standard output

In PowerShell...