How to do an MSBuild copy command that doesn't overwrite existing files?

msbuild

Solution

In your link there is an attribute "SkipUnchangedFiles". Add that to the copy task and set it to "true".

<Copy SourceFiles="@(Packages)" DestinationFolder="\\server\nuget\packages\" SkipUnchangedFiles="true" />

EDIT: I set up a sample project with the following.

<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
    <ItemGroup> 
        <ExistingPackages Include="dest\*.*" />
        <Packages Include="src\*.*" Exclude="@(ExistingPackages -> 'src\%(FileName)%(Extension)')" />
    </ItemGroup>
    <Target Name="Build">
        <Message Text="PackagesToCopy @(Packages)" Importance="high" />
    </Target>
</Project>

Folder + file taxonomy is:

src\
    doc1.txt
    doc2.txt
    doc3.txt
    doc4.txt
    doc5.txt
    doc6.txt
dest\
    doc2.txt
    doc4.txt
    doc6.txt
CopyNew.proj

When I run `msbuild.exe CopyNew.proj`, I get the following output:

Build:
  PackagesToCopy src\doc1.txt;src\doc3.txt;src\doc5.txt

So now @(Packages) no longer contains the files that exist in the destination folder!

Problem

Looking at the documentation for the Copy task, I don't see an obvious way to copy files without overwriting existing files at the destination. I only want to copy new files. What I have so far: ``` <ItemGroup> <Packages Include=".nuget-publish\*.*" /> </ItemGroup> <Copy SourceFiles="@(Packages)" DestinationFolder="\\server\nuget\packages\" /> ```

Original source