如何强制 Robocopy 覆盖文件? [英] How do I force Robocopy to overwrite files?

问题描述

一般来说，Robocopy 会忽略上次写入日期和文件大小相同的文件.我们怎样才能摆脱这种设计?我想用 Robocopy 强制覆盖.

In general, Robocopy ignores files for which lastwrittendate and filesize are the same. How can we escape this design? I'd like to force overwriting with Robocopy.

我希望 dst\sample.txt 应该写成 test001.但是这些文件被 Robocopy 识别为相同的文件，不会被覆盖.在这种情况下，/IS"选项无效.

I expected that dst\sample.txt should be written test001. But these file are recognized as the same files by Robocopy and not overwritten. The "/IS" option is not effective in this case.

New-Item src -itemType Directory
New-Item dst -itemType Directory
New-Item src\sample.txt -itemType File -Value "test001"
New-Item dst\sample.txt -itemType File -Value "test002"
Set-ItemProperty src\sample.txt -Name LastWriteTime -Value "2016/1/1 15:00:00"
Set-ItemProperty dst\sample.txt -Name LastWriteTime -Value "2016/1/1 15:00:00"

ROBOCOPY.exe src dst /COPYALL /MIR
Get-Content src\sample.txt, dst\sample.txt
> test001
> test002

ROBOCOPY.exe src dst /COPYALL /MIR /IS
Get-Content src\sample.txt, dst\sample.txt
> test001
> test002

推荐答案

来自 the文档:

/is 包含相同的文件./it 包括调整过的"文件.

/is Includes the same files. /it Includes "tweaked" files.

相同文件"是指相同(名称、大小、时间、属性)的文件.调整文件"是指名称、大小和时间相同但属性不同的文件.

"Same files" means files that are identical (name, size, times, attributes). "Tweaked files" means files that have the same name, size, and times, but different attributes.

robocopy src dst sample.txt /is      # copy if attributes are equal
robocopy src dst sample.txt /it      # copy if attributes differ
robocopy src dst sample.txt /is /it  # copy irrespective of attributes

这个答案超级用户对选择参数匹配的文件类型有很好的解释.

This answer on Super User has a good explanation of what kind of files the selection parameters match.

话虽如此，我可以重现您描述的行为，但根据我对文档和测试中生成的输出 robocopy 的理解，我认为这是一个错误.

With that said, I could reproduce the behavior you describe, but from my understanding of the documentation and the output robocopy generated in my tests I would consider this a bug.

PS C:\temp> New-Item src -Type Directory >$null
PS C:\temp> New-Item dst -Type Directory >$null
PS C:\temp> New-Item src\sample.txt -Type File -Value "test001" >$null
PS C:\temp> New-Item dst\sample.txt -Type File -Value "test002" >$null
PS C:\temp> Set-ItemProperty src\sample.txt -Name LastWriteTime -Value "2016/1/1 15:00:00"
PS C:\temp> Set-ItemProperty dst\sample.txt -Name LastWriteTime -Value "2016/1/1 15:00:00"
PS C:\temp> robocopy src dst sample.txt /is /it /copyall /mir
...
  Options : /S /E /COPYALL /PURGE /MIR /IS /IT /R:1000000 /W:30

------------------------------------------------------------------------------

                           1    C:\temp\src\
            Modified                   7        sample.txt

------------------------------------------------------------------------------

               Total    Copied   Skipped  Mismatch    FAILED    Extras
    Dirs :         1         0         0         0         0         0
   Files :         1         1         0         0         0         0
   Bytes :         7         7         0         0         0         0
...
PS C:\temp> robocopy src dst sample.txt /is /it /copyall /mir
...
  Options : /S /E /COPYALL /PURGE /MIR /IS /IT /R:1000000 /W:30

------------------------------------------------------------------------------

                           1    C:\temp\src\
            Same                       7        sample.txt

------------------------------------------------------------------------------

               Total    Copied   Skipped  Mismatch    FAILED    Extras
    Dirs :         1         0         0         0         0         0
   Files :         1         1         0         0         0         0
   Bytes :         7         7         0         0         0         0
...
PS C:\temp> Get-Content .\src\sample.txt
test001
PS C:\temp> Get-Content .\dst\sample.txt
test002

该文件被列为已复制，并且由于它在第一次robocopy运行后成为同一个文件，至少时间是同步的.然而，即使根据输出复制了七个字节，尽管设置了数据标志(通过 /copyall)，但在两种情况下都没有数据实际写入目标文件.如果显式设置数据标志 (/copy:d)，行为也不会改变.

The file is listed as copied, and since it becomes a same file after the first robocopy run at least the times are synced. However, even though seven bytes have been copied according to the output no data was actually written to the destination file in both cases despite the data flag being set (via /copyall). The behavior also doesn't change if the data flag is set explicitly (/copy:d).

我不得不修改上次写入时间才能让 robocopy 真正同步数据.

I had to modify the last write time to get robocopy to actually synchronize the data.

PS C:\temp> Set-ItemProperty src\sample.txt -Name LastWriteTime -Value (Get-Date)
PS C:\temp> robocopy src dst sample.txt /is /it /copyall /mir
...
  Options : /S /E /COPYALL /PURGE /MIR /IS /IT /R:1000000 /W:30

------------------------------------------------------------------------------

                           1    C:\temp\src\
100%        Newer                      7        sample.txt

------------------------------------------------------------------------------

               Total    Copied   Skipped  Mismatch    FAILED    Extras
    Dirs :         1         0         0         0         0         0
   Files :         1         1         0         0         0         0
   Bytes :         7         7         0         0         0         0
...
PS C:\temp> Get-Content .\dst\sample.txt
test001

公认的丑陋解决方法是更改​​相同/调整文件的最后写入时间以强制 robocopy 复制数据:

An admittedly ugly workaround would be to change the last write time of same/tweaked files to force robocopy to copy the data:

& robocopy src dst /is /it /l /ndl /njh /njs /ns /nc |
  Where-Object { $_.Trim() } |
  ForEach-Object {
    $f = Get-Item $_
    $f.LastWriteTime = $f.LastWriteTime.AddSeconds(1)
  }
& robocopy src dst /copyall /mir

切换到 xcopy 可能是您的最佳选择:

Switching to xcopy is probably your best option:

& xcopy src dst /k/r/e/i/s/c/h/f/o/x/y

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