Replace method is not working on my string variables-CodePudding

I wrote a script to extract the URL and Revision Number from svn info command of a svn repository and save the result in a .txt file.

The $revision and $url are both strings, so the replace method should work on them but it doesn't. Is there possibly something wrong in my code causing this?

$TheFilePath = "C:\Users\MyPC\REPOSITORY\NewProject\OUTPUT.txt"

echo "#- Automatic Package Update `n----------"| Out-File -FilePath $TheFilePath
 
$url = svn info C:\Users\MyPC\REPOSITORY\NewProject\trunk | Select-String -Pattern 'URL' -CaseSensitive -SimpleMatch | select-object -First 1 
$url | Add-Content -path $TheFilePath
$revision = svn info C:\Users\MyPC\REPOSITORY\NewProject\trunk | Select-String -Pattern 'Revision' -CaseSensitive -SimpleMatch | $revision.Replace('Revision','srcrev')
$revision | Add-Content -path $TheFilePath

here is the output of svn info (Irrelevant outputs have been omitted) :

Path: .
Working Copy Root Path: C:\Users\MyPC\REPOSITORY\NewProject\trunk
URL: https://svn.mycompany.de/svn/NewProject/trunk
Relative URL: ^/trunk
Repository Root: https://svn.mycompany.de/svn/NewProject
Revision: 5884

And here is what I get inside the .txt file , running the code :

#- Automatic Package Update 
----------
URL: https://svn.mycompany.de/svn/NewProject/trunk
Revision: 5884
----------

CodePudding user response：

Looking at the example output of svn info here and the example you just provided, you should be able to get the info you need easier with ConvertFrom-StringData then with Select-String.

In PowerShell < 7.x you can use ConvertFrom-StringData on the output of svn info after changing the colon (:) delimiter into an equal sign (=) to get a Hashtable with all properties and values. Then, using calculated properties you can extract the items you're interested in and save as CSV file for instance like this:

$svnInfo = svn info 'C:\Users\MyPC\REPOSITORY\NewProject\trunk'
$result  = $svnInfo -replace '(?<!:.*):', '=' | ConvertFrom-StringData | 
           Select-Object @{Name = 'URL'; Expression = {$_['URL']}}, 
                         @{Name = 'srcrev'; Expression = {$_['Revision']}}

# output on screen
$result | Format-Table -AutoSize

# output to CSV file
$result | Export-Csv -Path 'C:\Users\MyPC\REPOSITORIES\NewProject\OUTPUT.csv' -NoTypeInformation

Regex details on the -replace to replace only the first occurrence of the colon:

(?<!        Assert that it is impossible to match the regex below with the match ending at this position (negative lookbehind)
   :        Match the character “:” literally
   .        Match any single character
      *     Between zero and unlimited times, as many times as possible, giving back as needed (greedy)
)          
:           Match the character “:” literally

If you're using PowerShell 7 or higher, tghings get easier because then you have an extra -Delimiter parameter:

$svnInfo = svn info 'C:\Users\MyPC\REPOSITORY\NewProject\trunk'
$result  = $svnInfo -replace '(?<!:.*):', '=' | ConvertFrom-StringData -Delimiter ':' | 
           Select-Object @{Name = 'URL'; Expression = {$_['URL']}}, 
                         @{Name = 'srcrev'; Expression = {$_['Revision']}}
# output on screen
$result | Format-Table -AutoSize

# output to CSV file
$result | Export-Csv -Path 'C:\Users\MyPC\REPOSITORIES\NewProject\OUTPUT.csv' -NoTypeInformation

CodePudding user response：

$revision doesn't exist until after the svn command is done.

Use the ForEach-Object cmdlet and refer to the current match as $_ to modify the output object inline - the matched line in the output from Select-String is stored in a property called Line:

$revision = svn info C:\Users\MyPC\REPOSITORY\NewProject\trunk |Select-String -Pattern 'Revision' -CaseSensitive -SimpleMatch |ForEach-Object { $_.Line.Replace('Revision', 'srcrev') }