Discover a command by using the help system

  • 1 minute

By using the built-in help system in PowerShell, you can find out more about a specific command. You use the Get-Command cmdlet to locate a command that you need. After you've located the command, you might want to know more about what the command does and various ways to call it.

Discover cmdlets by using the help system and Get-Help

You can use the Get-Help core cmdlet to learn more about a command. Typically, you invoke Get-Help by specifying it by name and adding the -Name flag that contains the name of the cmdlet you want to learn about. Here's an example:

Get-Help -Name Get-Help

Update help

New versions of PowerShell don't include the help system by default. The first time you run Get-Help, you're asked to install the help files. You can also run the Update-Help cmdlet to install the help files. Because a call to Update-Help downloads many help files, the command can fetch only once per day by default. You can override this fetching behavior by using the -Force flag.

You update the help files differently on Windows compared to Linux or macOS. The process differs because when you run the Update-Help cmdlet, help files are fetched over the internet by matching your computer's culture. On Windows, a culture is already installed, but it's missing on Linux and macOS. So you need to specify a culture when you update help files on Linux and macOS.

Here's an example command:

Update-Help -UICulture en-US -Verbose

This command specifies the -UICulture flag. It gives it the value en-US, which fetches US English help files. To update your help files on macOS or Linux, use a culture that corresponds to your machine's culture.

Explore help sections

When you invoke Get-Help on a cmdlet, a help page is returned. The page includes many sections. You'll likely see these common sections:

  • NAME: Provides the name of the command.
  • SYNTAX: Shows ways to call the command by using a combination of flags, and sometimes, allowed parameters.
  • ALIASES: Lists any aliases for a command. An alias is a different name for a command, and it can be used to invoke the command.
  • REMARKS: Provides information about what commands to run to get more help for this command.
  • PARAMETERS: Provides details about the parameter. It lists its type, a longer description, and acceptable values, if applicable.

Filter the help response

If you don't want to display the full help page, narrow the response by adding flags to your Get-Help command. Here are some flags you can use:

  • Full: Returns a detailed help page. It specifies information like parameters, inputs, and outputs that you don't get in the standard response.
  • Detailed: Returns a response that looks like the standard response, but it includes a section for parameters.
  • Examples: Returns only examples, if any exist.
  • Online: Opens a web page for your command.
  • Parameter: Requires a parameter name as an argument. It lists a specific parameter's properties.

For example, you can use the following command to return only the Examples section of the help page.

Get-Help Get-FileHash -Examples

Improve the reading experience

Running Get-Help returns the entire help page. The page might not provide the best reading experience. You might have to scroll to find the section you want to read. A better approach is to use the help alias. The help alias pipes Get-Help into a function that ensures that your output is readable line by line. It also makes the response readable page by page, by paginating the output. You'll use the help alias in the next unit.