Replacing strings in a file containing ${Some string in variable} in powershell

Question

I have text file which contains some keys of an hash table in the form of ${key}. I need to parse the text file and replace ${key} with it's value. Below is the code i am using

    #$config is the hashtable
   $document = Get-Content sample.txt
    foreach ($conf in $config.Keys) {
        [string]$match = '${' + $conf + '}'
        $document = $document.Replace($match, $($config.$conf))
        }
    }

I have tried below alternatives for $match string

[string]$match = "`${" + $conf + "}"

[string]$match='${'
$match+=$conf
$match+='}'

I even tried hard coding the string as $match='${BACKUP_FOLDER}' but in all the cases it does nothing. I have also tried -match to see if something matches but it always returns false. I have confirmed that the text file contains several patterns of ${key} format and if i copy the output of $match and search in the file i can find the patterns. Could you please point out what's wrong. I am using Powershell V5.0

Sample input

$config=@{"BACKUP_DIR"="_Backup";"STAGING_DIR"="_Staging"}

Contents of sample.txt

Overwrites the contents of new installation with old installation 
    Always use / as path seperator-->
    <!-- <rename path="" newName=""/> -->
    <!-- 
    ${BACKUP_DIR}
    rename-> rename file/directory in new installation

Output: ${BACKUP_DIR} should be replaced with _Backup

Please edit the question and add sample input and desired output data. — vonPryz
– vonPryz, Commented Jul 25, 2017 at 11:45

G42 · Accepted Answer · 2017-07-25 13:36:51Z

1

Looks like there're a couple of typos in the hashtable. Following is a complete solution you can save as script and run, or copy to console.

$document = @'
Overwrites the contents of new installation with old installation 
    Always use / as path seperator-->
    <!-- <rename path="" newName=""/> -->
    <!-- 
    ${BACKUP_FOLDER}
    rename-> rename file/directory in new installation
'@

$config=@{"BACKUP_FOLDER"="_Backup";"STAGING_DIR"="_Staging"}

Write-Output "`n`nINPUT`n$document"

foreach ($conf in $config.Keys) {
        [string]$match = '${' + $conf + '}'
        $document = $document.Replace($match, $config.$conf)
}

Write-Output "`n`nOUTPUT`n$document"

answered Jul 25, 2017 at 13:36

G42

10.1k2 gold badges22 silver badges36 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

Pramod Over a year ago

Thanks @gms0ulman. Typo was just in the question. Your script works when i run it as standalone script but when i incorporate in my main script it's not working. Looks like the issue is something else. Some more head scratching to be done :(

G42 Over a year ago

@PramodAhanya To confirm; have you noticed the different 2nd argument in .Replace, $config.$conf?

Pramod Over a year ago

sorry another typo in question. i am using $config.$conf in the script.

G42 Over a year ago

@PramodAhanya BACKUP_DIR in hashtable and BACKUP_FOLDER in config also a typo?

Collectives™ on Stack Overflow

Replacing strings in a file containing ${Some string in variable} in powershell

1 Answer 1

4 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

4 Comments

Your Answer

Sign up or log in

Post as a guest

Related