根据大小将文本文件拆分为较小的文件 (Windows)

Question

偶尔会创建日志 (.txt) 文件，这些文件太大而无法打开 (5GB+)，我需要创建一个解决方案，将其拆分为更小的可读块以在写字板中使用。这是在 Windows Server 2008 R2 中。

我需要一个批处理文件、powerShell 或类似的解决方案。理想情况下，应该对每个文本文件包含不超过 999 MB 的内容进行硬编码，并且不要停在一行的中间。

我在https://gallery.technet.microsoft.com/scriptcenter/PowerShell-Split-large-log-6f2c4da0找到了一个类似于我的需求的解决方案，有时可以（按行数）

############################################# 
# Split a log/text file into smaller chunks # 
############################################# 

# WARNING: This will take a long while with extremely large files and uses lots of memory to stage the file 

# Set the baseline counters  
# Set the line counter to 0  
$linecount = 0 

# Set the file counter to 1. This is used for the naming of the log files      
$filenumber = 1

# Prompt user for the path  
$sourcefilename = Read-Host "What is the full path and name of the log file to split? (e.g. D:\mylogfiles\mylog.txt)"   

# Prompt user for the destination folder to create the chunk files      
$destinationfolderpath = Read-Host "What is the path where you want to extract the content? (e.g. d:\yourpath\)"    
Write-Host "Please wait while the line count is calculated. This may take a while. No really, it could take a long time." 

# Find the current line count to present to the user before asking the new line count for chunk files  
Get-Content $sourcefilename | Measure-Object | ForEach-Object { $sourcelinecount = $_.Count }   

#Tell the user how large the current file is  
Write-Host "Your current file size is $sourcelinecount lines long"   

# Prompt user for the size of the new chunk files  
$destinationfilesize = Read-Host "How many lines will be in each new split file?"   

# the new size is a string, so we convert to integer and up 
# Set the upper boundary (maximum line count to write to each file)    
$maxsize = [int]$destinationfilesize     
Write-Host File is $sourcefilename - destination is $destinationfolderpath - new file line count will be $destinationfilesize 

# The process reads each line of the source file, writes it to the target log file and increments the line counter. When it reaches 100000 (approximately 50 MB of text data)  
$content = get-content $sourcefilename | % {
Add-Content $destinationfolderpath\splitlog$filenumber.txt "$_"    
$linecount ++   
If ($linecount -eq $maxsize) { 
    $filenumber++ 
    $linecount = 0    }  }   
# Clean up after your pet  
[gc]::collect()   
[gc]::WaitForPendingFinalizers 
()

但是，当我运行它时，我在 powershell 中遇到了许多类似于以下内容的错误：

Add-Content : The process cannot access the file 'C:\Desktop\splitlog1.txt' 
because it is being used by another process...

所以我寻求帮助修复上述代码，或者帮助创建不同/更好的解决方案。

Answer 1

好的，我接受了挑战。这是应该适合您的功能。它可以按行拆分文本文件，在不超过大小字节的情况下，将尽可能多的完整输入行放入每个输出文件中。

注意：不能严格执行输出文件大小限制。

示例：输入文件包含两个非常长的字符串，每个 1Mb。如果您尝试将此文件拆分为 512KB 的块，则生成的每个文件将为 1MB。

功能Split-FileByLine：

<#
.Synopsis
    Split text file(s) by lines, put into each output file as many complete lines of input as possible without exceeding size bytes.

.Description
    Split text file(s) by lines, put into each output file as many complete lines of input as possible without exceeding size bytes.
    Note, that output file size limit can't be strictly enforced. Example: input files contains two very long strings, 1Mb each.
    If you try to split this file into the 512KB chunks, resulting files will be 1MB each.

    Splitted files will have orinignal file's name, followed by the "_part_" string and counter. Example:
    Original file: large.log
    Splitted files: large_part_0.log, large_part_1.log, large_part_2.log, etc.

.Parameter FileName
    Array of strings, mandatory. Filename(s) to split.

.Parameter OutPath
    String, mandatory. Folder, where splittedfiles will be stored. Will be created, if not exists.

.Parameter MaxFileSize
    Long, mandatory. Maximum output file size. When output file reaches this size, new file will be created.
    You can use PowerShell's multipliers: KB, MB, GB, TB,PB

.Parameter Encoding
    String. If not specified, script will use system's current ANSI code page to read the files.
    You can get other valid encodings for your system in PowerShell console like this:

    [System.Text.Encoding]::GetEncodings()

    Example:

    Unicode (UTF-7): utf-7
    Unicode (UTF-8): utf-8
    Western European (Windows): Windows-1252

.Example
    Split-FileByLine -FileName '.\large.log' -OutPath '.\splitted' -MaxFileSize 100MB -Verbose

    Split file "large.log" in current folder, write resulting files in subfolder "splitted", limit output file size to 100Mb, be verbose.

.Example
    Split-FileByLine -FileName '.\large.log' -OutPath '.\splitted' -MaxFileSize 100MB -Encoding 'utf-8'

    Split file "large.log" in current folder, write resulting files in subfolder "splitted", limit output file size to 100Mb, use UTF-8 encoding.

.Example
    Split-FileByLine -FileName '.\large_1.log', '.\large_2.log' -OutPath '.\splitted' -MaxFileSize 999MB

    Split files "large_1.log" ".\large_2.log" and  in current folder, write resulting files in subfolder "splitted", limit output file size to 999MB.

.Example
    '.\large_1.log', '.\large_2.log' | Split-FileByLine -FileName -OutPath '.\splitted' -MaxFileSize 999MB

    Split files "large_1.log" ".\large_2.log" and  in current folder, write resulting files in subfolder "splitted", limit output file size to 999MB.

#>
function Split-FileByLine
{
    [CmdletBinding()]
    Param
    (
        [Parameter(Mandatory = $true, ValueFromPipeline = $true, ValueFromPipelineByPropertyName = $true)]
        [string[]]$FileName,

        [Parameter(ValueFromPipelineByPropertyName = $true)]
        [string]$OutPath = (Get-Location -PSProvider FileSystem).Path,

        [Parameter(Mandatory = $true, ValueFromPipelineByPropertyName = $true)]
        [long]$MaxFileSize,

        [Parameter(ValueFromPipelineByPropertyName = $true)]
        [string]$Encoding = 'Default'
    )

    Begin
    {
        # Scriptblocks for common tasks
        $DisposeInFile = {
            Write-Verbose 'Disposing StreamReader'
            $InFile.Close()
            $InFile.Dispose()
        }

        $DisposeOutFile = {
            Write-Verbose 'Disposing StreamWriter'
            $OutFile.Flush()
            $OutFile.Close()
            $OutFile.Dispose()
        }

        $NewStreamWriter = {
            Write-Verbose 'Creating StreamWriter'
            $OutFileName = Join-Path -Path $OutPath -ChildPath (
                '{0}_part_{1}{2}' -f [System.IO.Path]::GetFileNameWithoutExtension($_), $Counter, [System.IO.Path]::GetExtension($_)
            )

            $OutFile = New-Object -TypeName System.IO.StreamWriter -ArgumentList (
                $OutFileName,
                $false,
                $FileEncoding
            ) -ErrorAction Stop
            $OutFile.AutoFlush = $true
            Write-Verbose "Writing new file: $OutFileName"
        }
    }

    Process
    {
        if($Encoding -eq 'Default')
        {
            # Set default encoding
            $FileEncoding = [System.Text.Encoding]::Default
        }
        else
        {
            # Try to set user-specified encoding
            try
            {
                $FileEncoding = [System.Text.Encoding]::GetEncoding($Encoding)
            }
            catch
            {
                throw "Not valid encoding: $Encoding"
            }
        }

        Write-Verbose "Input file: $FileName"
        Write-Verbose "Output folder: $OutPath"

        if(!(Test-Path -Path $OutPath -PathType Container)){
            Write-Verbose "Folder doesn't exist, creating: $OutPath"
            $null = New-Item -Path $OutPath -ItemType Directory -ErrorAction Stop
        }

        $FileName | ForEach-Object {
            # Open input file
            $InFile = New-Object -TypeName System.IO.StreamReader -ArgumentList (
                $_,
                $FileEncoding
            ) -ErrorAction Stop
            Write-Verbose "Current file: $_"

            $Counter = 0
            $OutFile = $null

            # Read lines from input file
            while(($line = $InFile.ReadLine()) -ne $null)
            {
                if($OutFile -eq $null)
                {
                    # No output file, create StreamWriter
                    . $NewStreamWriter
                }
                else
                {
                    if($OutFile.BaseStream.Length -ge $MaxFileSize)
                    {
                        # Output file reached size limit, closing
                        Write-Verbose "OutFile lenght: $($InFile.BaseStream.Length)"
                        . $DisposeOutFile
                        $Counter++
                        . $NewStreamWriter
                    }
                }

                # Write line to the output file
                $OutFile.WriteLine($line)
            }

            Write-Verbose "Finished processing file: $_"
            # Close open files and cleanup objects
            . $DisposeOutFile
            . $DisposeInFile
        }
    }
}

您可以像这样在脚本中使用它：

function Split-FileByLine
{
    # function body here
}

$InputFile = 'c:\log\large.log'
$OutputDir = 'c:\log_split'

Split-FileByLine -FileName $InputFile -OutPath $OutputDir -MaxFileSize 999MB