PowerShell读取队列数脚本空数组错误，求非正则替代方案

Hey there! Let's tackle your problem step by step—first fixing that annoying null array error, then giving you regex-free alternatives as you requested.

That error pops up because Select-String isn't finding a match for your regex pattern, so .Matches ends up being $null. When you try to access .Groups[1] on a null value, PowerShell throws that error. Here's why it might be happening and how to fix it:

1. File encoding issues: The bpdbjobs tool might be writing the output file in an encoding that Select-String doesn't parse correctly by default. Try explicitly setting the encoding when writing the file:

   .\bpdbjobs -summary -L | Out-File -Path $Output -Encoding ASCII
   

2. Add fault tolerance: Always check if the match was found before trying to access groups. Update your regex-based code to handle missing matches:

   $matchResult = Select-String -Pattern "Queued:\s+(\d+)" -Path $Output
   if ($matchResult) {
       $Queued = [int]$matchResult.Matches.Groups[1].Value
   } else {
       Write-Warning "Couldn't find the 'Queued:' line in the output file"
       exit 1 # Or handle this error however makes sense for your workflow
   }
   

Since you'd rather avoid regex, here are three straightforward methods that work with your file's format:

Method 1: String Splitting (Simple & Reliable) #

Read the file, filter for the "Queued:" line, split on the colon, trim whitespace, and convert to an integer:

$queuedLine = Get-Content $Output | Where-Object { $_ -like "Queued:*" }
if ($queuedLine) {
    $Queued = [int]($queuedLine -split ":")[1].Trim()
} else {
    Write-Warning "Queued jobs line not found in output"
    exit 1
}

Method 2: ConvertFrom-String (Structured Parsing) #

If you're using PowerShell 5.1 or newer, ConvertFrom-String lets you define a template to parse the entire summary at once—great if you ever need other job counts later:

# Define a template that matches your summary line format
$summaryTemplate = @"
Queued: {Queued:int}
Waiting-to-Retry: {WaitingToRetry:int}
Active: {Active:int}
Successful: {Successful:int}
Partially Successful: {PartiallySuccessful:int}
Failed: {Failed:int}
Incomplete: {Incomplete:int}
Suspended: {Suspended:int}
Total: {Total:int}
"@

# Parse the entire file into a structured object
$jobSummary = Get-Content $Output -Raw | ConvertFrom-String -TemplateContent $summaryTemplate
$Queued = $jobSummary.Queued # Access the Queued count directly

Method 3: Basic Select-String Match + Replace #

Use Select-String just to find the line, then strip out the "Queued:" text instead of using regex capture groups:

$queuedLine = Select-String -Pattern "Queued:" -Path $Output | Select-Object -ExpandProperty Line
if ($queuedLine) {
    $Queued = [int]($queuedLine -replace "Queued:", "").Trim()
} else {
    Write-Warning "Queued jobs line missing from output"
    exit 1
}

Here's your complete script with error handling and the string-splitting method integrated:

$Output = 'D:\alec.data\QueuedJobss.txt'
$nbAdminPath = 'D:\program files\veritas\netbackup\bin\admincmd'

# Switch to NetBackup admin directory (fail fast if path is invalid)
Set-Location -Path $nbAdminPath -ErrorAction Stop

# Generate the job summary file with explicit encoding
.\bpdbjobs -summary -L | Out-File -Path $Output -Encoding ASCII

# Extract Queued job count (regex-free)
$queuedLine = Get-Content $Output | Where-Object { $_ -like "Queued:*" }
if (-not $queuedLine) {
    Write-Warning "Failed to locate 'Queued:' entry in the job summary"
    exit 1
}
$Queued = [int]($queuedLine -split ":")[1].Trim()

# Send alert if threshold is exceeded
if ($Queued -gt 100 ) {
    $MailArgs = @{
        To          = 'alb2112@test.com'
        From        = 'netbackup@test.com'
        Subject     = 'Over 100 Queued Jobs!'
        Attachments = $Output
        Body        = 'Check Environment'
        SmtpServer  = 'smtp.test.com'
    }
    Send-MailMessage @MailArgs
}

• Adding -ErrorAction Stop to commands like Set-Location helps catch issues (like a missing NetBackup path) before they cause bigger problems.
• Explicitly setting file encoding avoids hidden character mismatches that can break string matching.
• All the regex-free methods are more readable if you're not comfortable with regex, and they work perfectly for your simple, consistent summary format.

内容的提问来源于stack exchange，提问作者AB2112