如何在 Powershell 脚本中维护会话信息

Question

我有如下脚本：

foreach ($var1 in (gc 1.txt)){
 // my code logic
}

这里的 1.txt 文件包含 abc、xyz、pqr 等值的列表， 如果由于任何脚本问题/ctrl+c 停止了脚本，则需要从上次停止的会话重新启动脚本。 要清楚脚本是否已停止在“xyz”处处理文件，并且当我重新启动脚本时，它应该只处理来自“xyz”的逻辑，但不应再次从“abc”重新启动。

请指导我实现这个逻辑。

提前致谢， 帕万·库马尔 D

Answer 1

您需要添加一些计数器并使用索引文件跟踪上次迭代。

然后确保您开始阅读使用select -Skip 中断的文件

<#
.NOTE
    The file index.txt is created at the first run and is used to store 
    the last line accessed of the file to process.

    The index read from index.txt is used to skip by already processed 
    lines at the start of the foreach.

    If the index doesn't need to be stored between session, then use
    a $global.index instead to speed up the script, instead of an index 
    file (or a RAM-drive, not very common any more).

    At each succefull iteration, the index is incremented and then stored in 
    index.txt.

    When starting the stored index.txt is compared with the numbers of 
    lines in the file and will through an error if it's passed End Of File.

    Make sure to **clear** the index.txt before starting the file process 
    fresh.
#>

#initialize counters
[int]$StartLine = Get-Content .\index.txt -ErrorAction SilentlyContinue
if (-not $StartLine){[int]$StartLine = 0} # First run will have no index file
$Index = $StartLine
[int]$LastLineOfFile = (get-content 1.txt).count - 1 # Arrays starts at 0

if ($Index -gt $LastLineOfFile){# Don't start if index passed EOF at last run
    Write-Error "Index passed end of file"
    return
}

foreach ($var in (Get-Content 1.txt | Select -Skip $StartLine)){
    
    "New loop: $Index" | Out-Host # will start empty

    "Processing value: $var" | Out-Host

    ####
    # Processing here
    ####

    "Done processing value: $var" | Out-Host

    $Index++ 
    $Index > index.txt
    "Index incremented" | Out-Host
}

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看，How to Create a RAM Disk on Windows Server?