📅 最后修改于: 2021-01-08 02:31:34 🧑 作者: Mango
自动变量是存储Windows PowerShell状态的那些变量。这些变量将包含用户和系统的信息，默认变量，运行时变量和PowerShell设置。这些变量可以由Windows PowerShell创建和维护。
以下是PowerShell中自动变量的列表：
| Variable name | Description |
|---|---|
| $$ | This variable is used to represent the last token in the last line, which is received by the session. |
| $? | This variable is used to represent the execution status of the last operation. If there is no error, it returns a True value otherwise False. |
| $^ | This variable is used to represent the first token in the last line, which is received by the session. |
| $_ | This variable acts as $PSItem. It contains the current object in the pipeline object. |
| $args | This variable contains an array of values for undeclared parameters that are passed to a script, function, or script block. |
| $ConsoleFileName | This variable is used to represent the path of the console file, which was recently used in the session. |
| $Error | This variable is used to contain an array of error objects which represent the most recent errors. |
| $Event | This variable is used to contain an object of PSEventArgs. PSEventArgs is an object used to represent an event that is being processed. |
| $EventSubscriber | This variable is used to contain an object of PSEventSubscriber. This object shows you an event subscriber of an event that is being processed. |
| $EventArgs | This variable is used to contain an object which represents the argument of the first event. |
| $false | This variable is used to represent the False. |
| $foreach | This variable is used to contain the enumerators of a ForEach loop. This variable exists only while the ForEach loop is executing. And it will be deleted after completion of the loop. |
| $Home | This variable is used to represent the full path of the user’s home directory. |
| $input | This variable contains an enumerator that enumerates all the inputs passed to the function. It is only available to script blocks and functions. |
| $Host | This variable contains an object which shows a current host application for the Windows PowerShell. |
| $IsLinux | If the current session is running on the Linux operating system, this variable contains a $True, otherwise $False. |
| $IsWindows | If the current session is running on the Windows operating system, this variable contains a $True, otherwise $False. |
| $IsMacOS | If the current session is running on MacOS operating system, this variable contains a $True, otherwise $False. |
| $null | This variable is used to represent a null or empty value. We can use it to represent an absent or undefined value in script and commands. |
| $PID | This variable displays the PID of the process, which is hosting the session of the current PowerShell. |
| $PSItem | This variable acts as $_. It contains the current object in the pipeline object. |
| $PSHome | This variable represents the full path of the installation directory for the Windows PowerShell. |
| $PSVersionTable | This variable is used to represent the read-only hash table, which displays the details about the version of PowerShell running in the current session. |
| $PWD | This variable is used to contain the path object, which shows you a full path of the current directory. |
| $ShellId | This variable is used to represent the identifier of the current shell. |