Using redirection within the script produces a uni

问题:

I am using Sandcastle Helpfile Builder to produce a helpfile (.chm). The project is a .shfbproj file, which is XML format, works with msbuild.

I want to automatically update the Footer text that appears in the generated .chm file. I use this snippet:

$newFooter = "<FooterText>MyProduct v1.2.3.4</FooterText>";

get-content  -Encoding ASCII $projFile.FullName | 
    %{$_ -replace '<FooterText>(.+)</FooterText>', $newFooter } > $TmpFile

move-item $TmpFile $projFile.FullName -force

The output directed to the $TmpFile is always a multi-byte string. But I don't want that. How do I set the encoding of the output to ASCII?

回答1:

You could change the $OutputEncoding variable before writing to the file. The other option is not to use the > operator, but instead pipe directly to Out-File and use the -Encoding parameter.

回答2:

The > redirection operator is a "shortcut" to Out-File. Out-File's default encoding is Unicode but you can chnage it to ASCII, so pipe to Out-File instead:

Get-Content -Encoding ASCII $projFile.FullName |
    % { $_ -replace '<FooterText>(.+)</FooterText>', $newFooter } |
    Out-File $tmpfile -Encoding ASCII

回答3:

| sc filename does the trick (sc being an alias for Set-Content)

for >> filename use | ac filename does the trick (ac being an alias for Add-Content)

回答4:

I found I had to use the following:

write-output "First line" | out-file -encoding ascii OutputFileName
write-output "Next line" | out-file -encoding ascii -append OutputFileName
....

Changing the output encoding using:

$OutputEncoding = New-Object -typename System.Text.ASCIIEncoding

did not work

回答5:

Just a little example using streams, although I realize this wasn't the original question.

C:\temp\ConfirmWrapper.ps1 -Force -Verbose 4>&1 6>&1 | Out-File -Encoding default -FilePath C:\temp\confirmLog.txt -Append

Will output the information(6) and verbose(4) streams to the output(1) stream and redirect all that to the out-file with ANSI(default) encoding.