筆記一下輸出到文本的語法
覆蓋該檔 a.out
$env:path > a.out附加到該檔 a.out
$env:path >> a.out完整說明
The Windows PowerShell redirection operators use the following characters
to represent each output type:
* All output
1 Success output
2 Errors
3 Warning messages
4 Verbose output
5 Debug messages
NOTE: The All (*), Warning (3), Verbose (4) and Debug (5) redirection operators were introduced
in Windows PowerShell 3.0. They do not work in earlier versions of Windows PowerShell.
The Windows PowerShell redirection operators are as follows.
Operator Description Example
-------- ---------------------- ------------------------------
> Sends output to the Get-Process > Process.txt
specified file.
>> Appends the output to dir *.ps1 >> Scripts.txt
the contents of the
specified file.
2> Sends errors to the Get-Process none 2> Errors.txt
specified file.
2>> Appends errors to Get-Process none 2>> Save-Errors.txt
the contents of the
specified file.
2>&1 Sends errors (2) and Get-Process none, Powershell 2>&1
success output (1)
to the success
output stream.
3> Sends warnings to the Write-Warning "Test!" 3> Warnings.txt
specified file.
3>> Appends warnings to Write-Warning "Test!" 3>> Save-Warnings.txt
the contents of the
specified file.
3>&1 Sends warnings (3) and function Test-Warning
success output (1) { Get-Process PowerShell;
to the success Write-Warning "Test!" }
output stream. Test-Warning 3>&1
4> Sends verbose output to Import-Module * -Verbose 4> Verbose.txt
the specified file.
4>> Appends verbose output Import-Module * -Verbose 4>> Save-Verbose.txt
to the contents of the
specified file.
4>&1 Sends verbose output (4) Import-Module * -Verbose 4>&1
and success output (1)
to the success output
stream.
5> Sends debug messages to Write-Debug "Starting" 5> Debug.txt
the specified file.
5>> Appends debug messages Write-Debug "Saving" 5>> Save-Debug.txt
to the contents of the
specified file.
5>&1 Sends debug messages (5) function Test-Debug
and success output (1) { Get-Process PowerShell
to the success output Write-Debug "PS" }
stream. Test-Debug 5>&1
*> Sends all output types function Test-Output
to the specified file. { Get-Process PowerShell, none
Write-Warning "Test!"
*>> Appends all output types Write-Verbose "Test Verbose"
to the contents of the Write-Debug "Test Debug" }
specified file.
Test-Output *> Test-Output.txt
*>&1 Sends all output types Test-Output *>> Test-Output.txt
(*) to the success output Test-Output *>&1
stream.
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.
To force the redirection of content to a read-only, hidden, or system file,
use the Out-File cmdlet with its Force parameter. When you are writing to
files, the redirection operators use Unicode encoding. If the file has a
different encoding, the output might not be formatted correctly. To
redirect content to non-Unicode files, use the Out-File cmdlet with its
Encoding parameter.REF
What does '>>' do in powershell? - Stack Overflow
