The most common PowerShell pitfall for beginners: What to do if an error occurs when the command does not exist
When you try to use PowerShell in a Windows system for the first time, you will most likely encounter this error message: "Get-: The word 'Get-' is not considered the name of a command line tool." This is not your mistake, but a learning process that every developer goes through.
The reason why the command does not exist
Spelling errors and grammatical oversights
On the occasion of the MBTI personality test on June 20, 2018, at 5:59 pm, a user posted a request for help on the technical forum. At that time, he executed the "Get-" command 16personalities test in the C:system32 directory of the Windows system, but the system returned an error that the command did not exist. This situation is extremely common in daily work, especially when tasks need to be executed quickly, resulting in errors due to incomplete commands being entered.
Missing necessary module loading
Various PowerShell command sets are distributed in different modules. If you have not imported the corresponding module in advance, even if the command name is completely correct, the system will prompt that the command cannot be found. According to Microsoft's official documentation, PowerShell version 5.1 has more than 1,300 built-in commands, but only the core module is loaded by default.
Install and import modules correctly
Use the Install-Module command
If the feature you need actually exists but is not installed, you can use the PowerShell Gallery to get it. For example, if you need Azure-related commands, you can execute the "Install-Module -Name Az" command to install the entire Azure module. This operation requires administrator rights and is recommended to be performed on Windows 10 or Windows 11 systems launched after 2020.
Manually import installed modules
After completing the installation, you must use the "Import-Module" command to import the module into the current session. For example, when importing the Active Directory module, just execute "Import-Module ActiveDirectory". If you want to automatically load specific modules every time you start PowerShell, you can add these commands to your PowerShell configuration file.
Create custom commands
Write simple functions
If you have needs and often use a certain command combination, you can create your own function. For example, if you often need to query the system service status, you can write a function that encapsulates the common parameters of the "Get – Service" command, and save these functions in your script file, so that you can call them like built-in commands.
Use script module
Faced with more complex functional requirements, you can consider creating script modules. Create a .psm1 file, define a number of corresponding functions in it, and then use "Import-Module" to import. This method has been widely used in DevOps practice since 2019, especially in continuous integration and continuous deployment processes.
Command discovery and exploration
Find the command using Get-Command
When you forget the specific command name, you can use a wildcard like "Get-Command service " to search. This command will list all commands covering the "service" keyword to help you quickly find the target. In Windows Server 2016 and later versions, the response speed of this command is extremely fast.
Learn how to use Get-Help
How can we use it correctly, after finding the command? Run "Get-Help Get-Service -Examples" to see specific usage examples. During Microsoft's 16personalities test during the document update period after 2018, at least 3 practical examples were given for each PowerShell command, which greatly reduced the difficulty of learning.
Handling execution policy restrictions
View current execution strategy
Sometimes even if the command exists, it cannot be run due to execution policy restrictions. Use "Get-ExecutionPolicy" to view the current policy settings. In Windows 10 Home Edition, the default execution policy is generally "Restricted", which means that no scripts are allowed to be executed.
Modify execution strategy
If you need to run a script written by yourself, you can change the execution policy to "RemoteSigned", execute the "Set – ExecutionPolicy RemoteSigned" command, and then confirm the modification. This operation only needs to be performed once, and you can run the locally written script normally. System administrators in enterprise environments have generally adopted this configuration since 2017.
Common error troubleshooting steps
Check the source of the command
When encountering a command without related errors, you must first confirm whether the command belongs to a built-in category, originates from a certain module, or is a third-party tool. Then execute the "Get-Command -CommandType Cmdlet" operation to view all available built-in commands, and then determine whether your target is within the scope of those commands.
Verify environment variables
When PowerShell searches for commands, it will search the paths specified in the system environment variables. If some executable files are not within these paths, it will also give a prompt that the command cannot be found. Use "$env:Path" to view the current path configuration. Be sure to ensure that the installation directory of the required tools has been added correctly.
What's the most troublesome error you've encountered while using PowerShell? Feel free to share your experiences in the comment area. I will write an article to answer the three questions with the most likes. If you feel that this article is helpful to you, don’t forget to forward it to your friends who are also in the stage of learning PowerShell.
