PowerShell Invoke-Command: Escape Single Quotes for bpflist

To properly escape single quotes in PowerShell Invoke-Command ScriptBlocks for the NetBackup bpflist -pattern parameter, wrap the quotes with backticks so they reach the external command intact—like *‘search text’*. Or build your pattern string locally with the required quotes (e.g., “‘search text’”), then pass it remotely using $using:pattern` to sidestep parsing issues entirely. Both tricks ensure bpflist sees the literal single quotes it demands, avoiding those frustrating zero-result outputs.

Contents

• The Problem with bpflist -pattern in Invoke-Command
• Why PowerShell Strips Your Quotes
• Method 1: Backtick-Escape Single Quotes
• Method 2: $using: with a Prebuilt Pattern
• Method 3: -ArgumentList and param()
• Troubleshooting Failed Attempts
• Sources
• Conclusion

The Problem with bpflist -pattern in Invoke-Command

You’re hitting a classic PowerShell quirk when running external tools like NetBackup’s bpflist inside an Invoke-Command ScriptBlock. The -pattern flag needs literal single quotes around the search text for wildcards to work right—think -pattern '*''search text''' on the command line, where bpflist matches backups containing “search text”.

But drop that into a ScriptBlock? PowerShell eagerly parses and strips those quotes before bpflist even blinks. Your attempts—straight single quotes, backticks without tweaks, escaped slashes, or plain variables—all collapse into something bpflist can’t parse. Result: zero matches, even when you know images exist.

This isn’t you. It’s how PowerShell handles string literals in remote blocks versus direct invocation. Local runs might limp by with doubles ("*search text*"), but bpflist is picky—it wants those singles for shell-like pattern expansion. And remoting via Invoke-Command amps up the stripping.

Why PowerShell Strips Quotes in Invoke-Command ScriptBlocks

Picture this: PowerShell tokenizes your ScriptBlock on the local machine, serializes it for the remote session, then reconstructs it there. Quotes get “helped” along the way—nested ones vanish to prevent premature expansion.

For external exes like bpflist, it’s worse. PowerShell doesn’t know (or care) that -pattern expects quoted args exactly as-is. It applies its own rules: single quotes delimit strings, backslashes escape, but in ScriptBlocks, especially remote ones, layers of parsing eat your escapes.

Stack Overflow discussions nail it: bpflist sees *search text* (no quotes) instead of *'search text'*. A Microsoft Docs GitHub issue digs deeper—external calls need extra escaping to defeat this multi-phase quote stripping.

Why your tries bombed:

• * 'search text' * → Quotes become string delimiters, bpflist gets unquoted args.
• *\'search text\'* → Backslash isn’t the right escape here; becomes literal.
• Doubles * "search text" * → bpflist often ignores them for patterns.

Short version? Don’t fight the parser. Outsmart it.

Method 1: Backtick-Escape Single Quotes

Backticks (`) are PowerShell’s escape character. Nest them around your single quotes to preserve them through the ScriptBlock gauntlet.

Here’s the fix for your example:

$startDate = "01/01/2024"
$endDate = "01/15/2024"
$client = "myclient"
$policy = "mypolicy"

Invoke-Command -ComputerName YourRemoteServer -ScriptBlock {
 bpflist -d $using:startDate -e $using:endDate -client $using:client -pt $using:policy -pattern "*`'search text`'*" 
}

Key change: *‘search text’*—the backticks force the singles to pass verbatim to bpflist. Tested on Stack Overflow, this delivers patterns like *'search text'* remotely.

Output? Actual matches, not zeros. But watch for complex patterns—too many nests get messy fast. Pro tip: Test locally first with & bpflist ... to mimic.

And yeah, use $using: for your date/client vars too. Safer than locals in ScriptBlocks.

Method 2: $using: with a Prebuilt Pattern

Hate manual escaping? Build the full pattern string locally—quotes and all—then inject it remotely with $using:. PowerShell treats $using: vars as opaque; no local parsing.

$startDate = "01/01/2024"
$endDate = "01/15/2024"
$client = "myclient"
$policy = "mypolicy"
$pattern = "*'search text'*' # Literal single quotes here!

Invoke-Command -ComputerName YourRemoteServer -ScriptBlock {
 bpflist -d $using:startDate -e $using:endDate -client $using:client -pt $using:policy -pattern $using:pattern
}

bpflist receives -pattern '*search text*' exactly. No backticks needed. This shines for dynamic searches—construct $pattern with -replace or regex if your text has embeds.

From another Stack Overflow thread, this avoids ScriptBlock creation headaches entirely. Cleaner than backticks, especially in loops.

What if text has singles inside? Double 'em: $pattern = "*''embedded' text''*". bpflist handles doubled escapes like shells do.

Method 3: -ArgumentList and param()

For ultimate control, pass the pattern as an explicit argument. Define param() in the ScriptBlock, splat via -ArgumentList.

$startDate = "01/01/2024"
$endDate = "01/15/2024"
$client = "myclient"
$policy = "mypolicy"
$patternArg = "*'search text'*"

Invoke-Command -ComputerName YourRemoteServer -ScriptBlock {
 param($pat)
 bpflist -d $using:startDate -e $using:endDate -client $using:client -pt $using:policy -pattern $pat
} -ArgumentList $patternArg

$patternArg ships untouched. Community advice loves this for EXEs—bypasses all quote wars.

Mix $using: for simple vars, -ArgumentList for complex strings. Scale it: pass arrays of patterns if needed.

Troubleshooting Failed Attempts

Still zeros? Let’s debug your specifics.

Run locally: bpflist -pattern "*'search text'*"—if no matches, your text/query is off. Remote? Add -Verbose or Start-Transcript in ScriptBlock.

Reddit threads echo this: wrap exes with & for locals, but remoting demands variables. Veritas forums suggest ie helper from Native module for auto-escaping, but variables win for reliability.

Edge case: Wildcards at ends? -pattern "'search*'" or "*search'". Always quote the whole thing.

Sources

1. Invoke-Command with single quotes in ScriptBlock
2. How do I pass quoted parameters to PowerShell Invoke-Command and ScriptBlocks?
3. Command line escaping single quote for PowerShell
4. Document the need for additional -escaping of double quotes when calling external programs
5. r/PowerShell: Invoke-Command / Double Quotation issue

Conclusion

Mastering single quotes for bpflist -pattern in PowerShell Invoke-Command boils down to three reliable paths: backtick-escaping for quick wins, $using: for clean variables, or -ArgumentList for precision. Pick based on complexity—variables scale best, dodging parser pitfalls forever. Test incrementally (local first, then remote), and you’ll pull those NetBackup images without the zero-result headaches. Your scripts just got bulletproof.