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Powershell single quote around variable when passing as argument

Hi Powershell experts,

please help.

Not able to fix below issue. Please note, I'm initiating/sending this cmd from aws cloudformation.

Step 1:
Within cloudformation script/scope, I get a value for RDSInstance.Endpoint.Address, which I'm passing it as a variable to below Step 2. Assume the value is 'newdb.us-east-2.rds.amazonaws.com'

Step 2: Cloudformation script looks like this when invoking

5-replaceDBURLinEachFile:
  command: !Sub |
    powershell.exe foreach($line in Get-Content C:\filepath.txt) {If (Test-Path -Path $line) {(Get-Content $line).replace('cxad1tpfvpbi.us-east-2.rds.amazonaws.com', ${RDSInstance.Endpoint.Address}) | Set-Content $line}}

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Step 3: But on the target server it failed, sorry I didnt capture the exact log. but it failed for missing single quote around the variable value.

powershell.exe foreach($line in Get-Content C:\filepath.txt) {If (Test-Path -Path $line) {(Get-Content $line).replace('cxad1tpfvpbi.us-east-2.rds.amazonaws.com', newdb.us-east-2.rds.amazonaws.com) | Set-Content $line}}

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How do I place single quote or handle this situation pls

please help, thanks in advance

ASKER CERTIFIED SOLUTION

oBdA

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enthuguy

ASKER

Thanks again oBdA :)

Learning from you as well. ;)

Qlemo

That replacement is done by the Cloudformation engine, obviously - it is not PowerShell doing that. So all you should need to do is make sure to include literal single quotes. As I don't know Cloudformation, I cannot tell if just putting single quotes around the variable expression works, or you need to somehow escape them for Cloudformation so it doesn't see them as quotes (and not apply any substitution).
I would start with simple single quotes, like

powershell.exe foreach($line in Get-Content C:\filepath.txt) {If (Test-Path -Path $line) {(Get-Content $line).replace('cxad1tpfvpbi.us-east-2.rds.amazonaws.com', '${RDSInstance.Endpoint.Address}') | Set-Content $line}}

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enthuguy

ASKER

Thanks so much oBdA. that helped me. :)

Another suggestion pls?
From the above scenario replacing db_url. Is it possible to replace two more variable in single line?
e.g right now i replacce db_url, Can I also replace db_user and db_pwd

oBdA

The result of a Replace() method is a string, so you can just add as many Replace() as you need

"SomeString".Replace('a', 'b').Replace('c', 'd').Replace('e', 'f')

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enthuguy

ASKER

Really, is PS that powerful? Nice :)

Something like this?

powershell.exe "foreach($line in Get-Content C:\filepath.txt) {If (Test-Path -Path $line) {(Get-Content $line).replace('old_db.rds.amazonaws.com', '${RDSInstance.Endpoint.Address}').replace('old_ueer', '${RDSInstance.user.name}').replace('old_pwd', '${RDSInstance.user.pwd}') | Set-Content $line}}"

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oBdA

That's actually the underlying .NET Framework, but, yes, it's that comfortable.
Be aware that the Replace() method is case sensitive.

enthuguy

ASKER

Thanks again oBdA!
and thanks Qlemo for your help.