PowerShell中2>＆1的含義是什么？

Question

我有以下腳本：

if( $timeout -ne $null )
{
    & $var$timeout 2>&1 > $logDir\$logName
}
else
{
    & $var2>&1 >  $logDir\$logName
}

我很好奇2>&1是什么; 或者，它代表什么。 我不知道它叫什么，否則，我會查一查。

Answer 1

它將標准錯誤（2）重定向到與標准輸出相同的位置（1）

Answer 2

文檔是你的朋友。 從PS> man about_Redirection

The Windows PowerShell redirection operators are as follows.

Operator  Description                Example
--------  ----------------------     ------------------------------
<snip>

2>&1      Sends errors (2) and       Get-Process none, Powershell 2>&1
          success output (1)
          to the success
          output stream.

<snip>

The syntax of the redirection operators is as follows:

   <input> <operator> [<path>\]<file>

If the specified file already exists, the redirection operators that do not
append data (> and n>) overwrite the current contents of the file without
warning. However, if the file is a read-only, hidden, or system file, the
redirection fails. The append redirection operators (>> and n>>) do not
write to a read-only file, but they append content to a system or hidden
file.