I'm starting to use PowerShell and am trying to figure out how to echo a system environment variable to the console to read it.

Neither of the below are working. The first just prints %PATH%, and the second prints nothing.

echo %PATH%
echo $PATH

kitfox

Ответов: 4

Ответы (4)

Prefix the variable name with env:

$env:path

Например, если вы хотите распечатать значение значения среды «MINISHIFT_USERNAME», то команда будет иметь вид:

$env:MINISHIFT_USERNAME

You can also enumerate all variables via the env drive:

Get-ChildItem env:

In addition to Mathias answer.

Although not mentioned in OP, if you also need to see the Powershell specific/related internal variables, you need to use Get-Variable:

$ Get-Variable

Name                           Value
----                           -----
$                              name
?                              True
^                              gci
args                           {}
ChocolateyTabSettings          @{AllCommands=False}
ConfirmPreference              High
DebugPreference                SilentlyContinue
EnabledExperimentalFeatures    {}
Error                          {System.Management.Automation.ParseException: At line:1 char:1...
ErrorActionPreference          Continue
ErrorView                      NormalView
ExecutionContext               System.Management.Automation.EngineIntrinsics
false                          False
FormatEnumerationLimit         4
...

К ним также относятся вещи, которые вы, возможно, установили в сценарии запуска вашего профиля.

Я сам с этим сталкивался. Я хотел посмотреть на пути, но каждый на отдельной строке. Это распечатает путь и разделит его точкой с запятой.

$env:path.Split(";")

The following is works best in my opinion:

Get-Item Env:PATH
  1. It's shorter and therefore a little bit easier to remember than Get-ChildItem. There's no hierarchy with environment variables.
  2. The command is symmetrical to one of the ways that's used for setting environment variables with Powershell. (EX: Set-Item -Path env:SomeVariable -Value "Some Value")
  3. If you get in the habit of doing it this way you'll remember how to list all Environment variables; simply omit the entry portion. (EX: Get-Item Env:)

I found the syntax odd at first, but things started making more sense after I understood the notion of Providers. Essentially PowerShell let's you navigate disparate components of the system in a way that's analogous to a file system.

What's the point of the trailing colon in Env:? Try listing all of the "drives" available through Providers like this:

PS> Get-PSDrive

I only see a few results... (Alias, C, Cert, D, Env, Function, HKCU, HKLM, Variable, WSMan). It becomes obvious that Env is simply another "drive" and the colon is a familiar syntax to anyone who's worked in Windows.

You can navigate the drives and pick out specific values:

Get-ChildItem C:\Windows
Get-Item C:
Get-Item Env:
Get-Item HKLM:
Get-ChildItem HKLM:SYSTEM

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