比较Powershell中的Filehash

时间：2012-07-31 18:03:24

标签： powershell hash

我是一个强大的力量。在下午的大部分时间里，我一直在盯着我的屏幕，试图找出如何比较两个不同目录中多个文件的文件哈希值。该脚本将文件从FTP站点下载到目录（$ cDlPath）中，并最终将它们复制到另一个目录（$ cDestPath）。我想比较文件中的filehash，以确保自下载以来没有任何变化。我正在使用Get-Hash cmdlet来获取文件哈希值，但我无法弄清楚如何比较两个哈希值。如果文件不相等，我希望能够按名称识别更改的文件，以便检查文件。

我一直在摆弄下面的代码，但它似乎并不是我追求的目标。

Compare-Object `
-ReferenceObject $(Get-ChildItem $cDestPath -Recurse | Where-Object {!$_.psiscontainer } | Get-Hash -Algorithm $cHashAlg) `
-DifferenceObject $(Get-ChildItem  $cDlPath -Recurse | Where-Object {!$_.psiscontainer } | Get-Hash -Algorithm $cHashAlg)

非常感谢任何帮助。

我正在使用下面的代码，我似乎更接近。

Compare-Object $(Get-ChildItem $cDlPath -Recurse $_ | Where-Object { !$_.PsIsContainer } |  
  Select-Object Name, FullName, Length, @{Name=”SHA256 Hash”; Expression={ Get-Hash $_.FullName  
  -Algorithm "SHA256" }}, LastWriteTime) $( Get-ChildItem $cDestPath -Recurse $_ | Where-Object  
  { !$_.PsIsContainer } | Select-Object Name, FullName, Length, @{Name=”SHA256 Hash”; 
  Expression={ Get-Hash $_.FullName -Algorithm "SHA256" }}, LastWriteTime) -property @
  ("Name", “FullName”,”SHA256 Hash”, "Length", "LastWriteTime" ) | Add-Content -Path $cLogFile

它仍然看起来不完全正确，因为有一些哈希是相同的，并且日志文件的输出是丑陋的。如果文件具有相同的哈希值，则文件应仅在日志文件中。

@{Name=nothing.xlsx; FullName=C:\Test\nothing.xlsx; SHA256 Hash=E74424B6324DE014CB0C896DA29D67A2A729E31DF57119E840CA4BD9A9E41754; Length=8891; LastWriteTime=7/31/2012 1:33:11 PM; SideIndicator=<=}
@{Name=test.txt; FullName=C:\Test\test.txt; SHA256 Hash=FC43E73579DB001751A29C1F7A8E2E36E46A53662B63013F0AE500AA896DE056; Length=174; LastWriteTime=7/31/2012 4:52:52 PM; SideIndicator=<=}
@{Name=testfile.txt; FullName=C:\Test\testfile.txt; SHA256 Hash=2B2DB80CAF93224A49A7C94E8EA5BCB1B86D421EA2DB83285149ECAE6DEAA105; Length=415; LastWriteTime=7/27/2012 12:01:21 PM; SideIndicator=<=}
@{Name=nothing.xlsx; FullName=C:\Test\Old\nothing.xlsx; SHA256 Hash=22603417927343A485862CE93790203EE7C2DB092C2060C92D44B736A01FD37E; Length=8978; LastWriteTime=7/31/2012 4:40:43 PM; SideIndicator=<=}
@{Name=test.txt; FullName=C:\Test\Old\test.txt; SHA256 Hash=FC43E73579DB001751A29C1F7A8E2E36E46A53662B63013F0AE500AA896DE056; Length=174; LastWriteTime=7/31/2012 4:52:52 PM; SideIndicator=<=}
@{Name=testfile.txt; FullName=C:\Test\Old\testfile.txt; SHA256 Hash=0B35A9F7F500B46469E2C1759F92D222983C4FDF4AAE316C0F2861FC70D0FD2B; Length=447; LastWriteTime=7/31/2012 4:52:40 PM; SideIndicator=<=}

5 个答案:

答案 0 :(得分：1)

必须有一个更漂亮的解决方案，但这是我最终使用的。

# Get the file hashes
$hashsourcefile = Get-Hash $file -Algorithm "SHA256"
$hashdestfile = Get-Hash $file2 -Algorithm "SHA256"

# Compare the hashes
Compare-Object -Referenceobject $hashsourcefile -Differenceobject $hashdestfile | % { If ($_.Sideindicator -ne " ==") {$diff+=1} }                  

# The Hashes are different. Note this in the log
if ($diff -ne 0)
{
    Add-Content -Path $cLogFile -Value " Source File Hash: $hashsourcefile does not equal 
    Existing Destination File Hash: $hashdestfile the files are NOT EQUAL."
}

答案 1 :(得分：0)

所以这是一个未经测试的解决方案，至少应该让你朝着正确的方向前进：

#first make a hash table of the files in folder 1 where the keys are the file hashes and the values are the file objects
$folder1Files = @{}
foreach($file in $cDestPath){
    $hash = Get-Hash $file
    if($folder1Files.ContainsKey($hash)){
        # A hash collision isn't likely but not unheard of. You should probably just handle them manually
        'There was a hash collision for {0} and {1} in folder {2}' -f $file.Name, $folder1Files[$hash].Name, $cDestPath
    }else{
        $folder1Files[$hash] = $file
    }
}
# Now do the same thing for folder 2
$folder2Files = @{}
foreach($file in $cDlPath){
    $hash = Get-Hash $file
    if($folder2Files.ContainsKey($hash)){
        # A hash collision isn't likely but not unheard of. You should probably just handle them manually
        'There was a hash collision for {0} and {1} in folder {2}' -f $file.Name, $folder1Files[$hash].Name, $cDlPath
    }else{
        $folder2Files[$hash] = $file
    }
}
# Actually you should really take those two bits and generalize them to a function that you pass a folder to and it returns the hash table.

# Now that you have your two sets of file hashes, use Compare-Object to find the diffs
$comparison = Compare-Object $folder1Files.Keys $folder2Files.Keys
foreach($diff in $comparison){
    if($diff.SideIndicator -eq '<='){
        'File {0} in folder {1} is different from any file in the other folder' -f $folder1Files[$diff.InputObject], $cDestPath
    }else{
        'File {0} in folder {1} is different from any file in the other folder' -f $folder2Files[$diff.InputObject], $cDLPath
    }
}

就像我说的那样，我现在没有时间来测试和解决任何错误，但至少应该作为伪代码来解决这个问题。

答案 2 :(得分：0)

这对我很有用 - 比较两个源代码分支。计数为1的组在另一个分支中没有MD5哈希双胞胎，例如：

$paths = 'c:\proj\trunk\source','c:\proj\branches\release\1.0\source'
ls $paths -r *.cs | Where {$_.PSPath -notmatch '\\obj\\'} | 
    Get-Hash | Select Path,HashString | Group HashString | 
    Where {$_.Count -eq 1} | Sort Count -desc | Format-List

答案 3 :(得分：0)

我意识到这是一个陈旧的线程（16个月大），但它是谷歌的最高结果，这意味着它获得了很多观点。我认为这可能会让其他人受益......

麦克是对的，有一个更漂亮的＆amp;使用Get-Hash的更简单的解决方案。您可以通过比较HashString来简单地比较IF语句中的哈希值。

# Get the file hashes
$hashSrc = Get-Hash $file -Algorithm "SHA256"
$hashDest = Get-Hash $file2 -Algorithm "SHA256"

# Compare the hashes & note this in the log
If ($hashSrc.HashString -ne $hashDest.HashString)
{
  Add-Content -Path $cLogFile -Value " Source File Hash: $hashSrc does not 
  equal Existing Destination File Hash: $hashDest the files are NOT EQUAL."
}

答案 4 :(得分：0)

使用MD5哈希的递归目录文件内容差异

我编写了这个纯PowerShell v3 +（无依赖关系）递归目录差异，它通过MD5哈希比较内容。使用-ExportSummary [summary/path]参数，它将为左侧和右侧目录导出一组csv差异以及差异的摘要文件。否则将在stdout上给出标准的Compare-Object差异结果。您可以将rdiff.ps1文件放入路径Set-ExecutionPolicy RemoteSigned，也可以将内容直接复制到脚本中。

<强> USAGE: rdiff path/to/left,path/to/right [-s path/to/summary/dir]

这是gist。建议使用gist版本，因为它可能在下面的版本中添加了其他功能。

#########################################################################
### USAGE: rdiff path/to/left,path/to/right [-s path/to/summary/dir]  ###
### ADD LOCATION OF THIS SCRIPT TO PATH                               ###
#########################################################################
[CmdletBinding()]
param (
  [parameter(HelpMessage="Stores the execution working directory.")]
  [string]$ExecutionDirectory=$PWD,

  [parameter(Position=0,HelpMessage="Compare two directories recursively for differences.")]
  [alias("c")]
  [string[]]$Compare,

  [parameter(HelpMessage="Export a summary to path.")]
  [alias("s")]
  [string]$ExportSummary
)

### FUNCTION DEFINITIONS ###

# SETS WORKING DIRECTORY FOR .NET #
function SetWorkDir($PathName, $TestPath) {
  $AbsPath = NormalizePath $PathName $TestPath
  Set-Location $AbsPath
  [System.IO.Directory]::SetCurrentDirectory($AbsPath)
}

# RESTORES THE EXECUTION WORKING DIRECTORY AND EXITS #
function SafeExit() {
  SetWorkDir /path/to/execution/directory $ExecutionDirectory
  Exit
}

function Print {
  [CmdletBinding()]
  param (
    [parameter(Mandatory=$TRUE,Position=0,HelpMessage="Message to print.")]
    [string]$Message,

    [parameter(HelpMessage="Specifies a success.")]
    [alias("s")]
    [switch]$SuccessFlag,

    [parameter(HelpMessage="Specifies a warning.")]
    [alias("w")]
    [switch]$WarningFlag,

    [parameter(HelpMessage="Specifies an error.")]
    [alias("e")]
    [switch]$ErrorFlag,

    [parameter(HelpMessage="Specifies a fatal error.")]
    [alias("f")]
    [switch]$FatalFlag,

    [parameter(HelpMessage="Specifies a info message.")]
    [alias("i")]
    [switch]$InfoFlag = !$SuccessFlag -and !$WarningFlag -and !$ErrorFlag -and !$FatalFlag,

    [parameter(HelpMessage="Specifies blank lines to print before.")]
    [alias("b")]
    [int]$LinesBefore=0,

    [parameter(HelpMessage="Specifies blank lines to print after.")]
    [alias("a")]
    [int]$LinesAfter=0,

    [parameter(HelpMessage="Specifies if program should exit.")]
    [alias("x")]
    [switch]$ExitAfter
  )
  PROCESS {
    if($LinesBefore -ne 0) {
      foreach($i in 0..$LinesBefore) { Write-Host "" }
    }
    if($InfoFlag) { Write-Host "$Message" }
    if($SuccessFlag) { Write-Host "$Message" -ForegroundColor "Green" }
    if($WarningFlag) { Write-Host "$Message" -ForegroundColor "Orange" }
    if($ErrorFlag) { Write-Host "$Message" -ForegroundColor "Red" }
    if($FatalFlag) { Write-Host "$Message" -ForegroundColor "Red" -BackgroundColor "Black" }
    if($LinesAfter -ne 0) {
      foreach($i in 0..$LinesAfter) { Write-Host "" }
    }
    if($ExitAfter) { SafeExit }
  }
}

# VALIDATES STRING MIGHT BE A PATH #
function ValidatePath($PathName, $TestPath) {
  If([string]::IsNullOrWhiteSpace($TestPath)) {
    Print -x -f "$PathName is not a path"
  }
}

# NORMALIZES RELATIVE OR ABSOLUTE PATH TO ABSOLUTE PATH #
function NormalizePath($PathName, $TestPath) {
  ValidatePath "$PathName" "$TestPath"
  $TestPath = [System.IO.Path]::Combine((pwd).Path, $TestPath)
  $NormalizedPath = [System.IO.Path]::GetFullPath($TestPath)
  return $NormalizedPath
}


# VALIDATES STRING MIGHT BE A PATH AND RETURNS ABSOLUTE PATH #
function ResolvePath($PathName, $TestPath) {
  ValidatePath "$PathName" "$TestPath"
  $ResolvedPath = NormalizePath $PathName $TestPath
  return $ResolvedPath
}

# VALIDATES STRING RESOLVES TO A PATH AND RETURNS ABSOLUTE PATH #
function RequirePath($PathName, $TestPath, $PathType) {
  ValidatePath $PathName $TestPath
  If(!(Test-Path $TestPath -PathType $PathType)) {
    Print -x -f "$PathName ($TestPath) does not exist as a $PathType"
  }
  $ResolvedPath = Resolve-Path $TestPath
  return $ResolvedPath
}

# Like mkdir -p -> creates a directory recursively if it doesn't exist #
function MakeDirP {
  [CmdletBinding()]
  param (
    [parameter(Mandatory=$TRUE,Position=0,HelpMessage="Path create.")]
    [string]$Path
  )
  PROCESS {
    New-Item -path $Path -itemtype Directory -force | Out-Null
  }
}

# GETS ALL FILES IN A PATH RECURSIVELY #
function GetFiles {
  [CmdletBinding()]
  param (
    [parameter(Mandatory=$TRUE,Position=0,HelpMessage="Path to get files for.")]
    [string]$Path
  )
  PROCESS {
    ls $Path -r | where { !$_.PSIsContainer }
  }
}

# GETS ALL FILES WITH CALCULATED HASH PROPERTY RELATIVE TO A ROOT DIRECTORY RECURSIVELY #
# RETURNS LIST OF @{RelativePath, Hash, FullName}
function GetFilesWithHash {
  [CmdletBinding()]
  param (
    [parameter(Mandatory=$TRUE,Position=0,HelpMessage="Path to get directories for.")]
    [string]$Path,

    [parameter(HelpMessage="The hash algorithm to use.")]
    [string]$Algorithm="MD5"
  )
  PROCESS {
    $OriginalPath = $PWD
    SetWorkDir path/to/diff $Path
    GetFiles $Path | select @{N="RelativePath";E={$_.FullName | Resolve-Path -Relative}},
                            @{N="Hash";E={(Get-FileHash $_.FullName -Algorithm $Algorithm | select Hash).Hash}},
                            FullName
    SetWorkDir path/to/original $OriginalPath
  }
}

# COMPARE TWO DIRECTORIES RECURSIVELY #
# RETURNS LIST OF @{RelativePath, Hash, FullName}
function DiffDirectories {
  [CmdletBinding()]
  param (
    [parameter(Mandatory=$TRUE,Position=0,HelpMessage="Directory to compare left.")]
    [alias("l")]
    [string]$LeftPath,

    [parameter(Mandatory=$TRUE,Position=1,HelpMessage="Directory to compare right.")]
    [alias("r")]
    [string]$RightPath
  )
  PROCESS {
    $LeftHash = GetFilesWithHash $LeftPath
    $RightHash = GetFilesWithHash $RightPath
    diff -ReferenceObject $LeftHash -DifferenceObject $RightHash -Property RelativePath,Hash
  }
}

### END FUNCTION DEFINITIONS ###

### PROGRAM LOGIC ###

if($Compare.length -ne 2) {
  Print -x "Compare requires passing exactly 2 path parameters separated by comma, you passed $($Compare.length)." -f
}
Print "Comparing $($Compare[0]) to $($Compare[1])..." -a 1
$LeftPath   = RequirePath path/to/left $Compare[0] container
$RightPath  = RequirePath path/to/right $Compare[1] container
$Diff       = DiffDirectories $LeftPath $RightPath
$LeftDiff   = $Diff | where {$_.SideIndicator -eq "<="} | select RelativePath,Hash
$RightDiff   = $Diff | where {$_.SideIndicator -eq "=>"} | select RelativePath,Hash
if($ExportSummary) {
  $ExportSummary = ResolvePath path/to/summary/dir $ExportSummary
  MakeDirP $ExportSummary
  $SummaryPath = Join-Path $ExportSummary summary.txt
  $LeftCsvPath = Join-Path $ExportSummary left.csv
  $RightCsvPath = Join-Path $ExportSummary right.csv

  $LeftMeasure = $LeftDiff | measure
  $RightMeasure = $RightDiff | measure

  "== DIFF SUMMARY ==" > $SummaryPath
  "" >> $SummaryPath
  "-- DIRECTORIES --" >> $SummaryPath
  "`tLEFT -> $LeftPath" >> $SummaryPath
  "`tRIGHT -> $RightPath" >> $SummaryPath
  "" >> $SummaryPath
  "-- DIFF COUNT --" >> $SummaryPath
  "`tLEFT -> $($LeftMeasure.Count)" >> $SummaryPath
  "`tRIGHT -> $($RightMeasure.Count)" >> $SummaryPath
  "" >> $SummaryPath
  $Diff | Format-Table >> $SummaryPath

  $LeftDiff | Export-Csv $LeftCsvPath -f
  $RightDiff | Export-Csv $RightCsvPath -f
}
$Diff
SafeExit
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