Why it doesn't change the content inside the file? - windows

Question

this code supposed to look for all demo.txt in the disk and change them from "demo" to "demodemo997182625" and then check if the file has changed or not
$found = 0;
$notfound = 0;
foreach ($file in Get-ChildItem -Path C:\ -Recurse -Filter demo.txt -ErrorAction SilentlyContinue )
{
(Get-Content $file).Replace("demo","demo997182625") | Set-Content $file
$x = (Get-Content $file).contain("demo997182625")
if($x -eq $null){
$found = 1 + $found;
}
else {
$notfound = 1 + $notfound;
}
}
Write-Host "Changed" $found;
Write-Host "Not Changed" $notfound;

Answer 1

A few remarks on your code:
the .Replace() and .Contains() string methods work case-sensitive, so .Replace("demo","demo997182625") won't find and replace "Demo". To have it work case-insensitively, use the -replace operator instead.
updated files can be reprocessed by Get-ChildItem, unless you have that part finish completely first. The easiest way to do that is by enclosing it between brackets
I would only save the file if there was something updated (i.e. the new value was found after -replace), otherwise leave it be
Get-ChildItem returns both FileInfo and DirectoryInfo objects. Since you are interested in changing files only, append the -File switch
best use the FullName property of the found file on the Get- and Set-Content cmdlets instead of the whole FileInfo object
$found = $notfound = 0
# surround the Get-ChildItem line with brackets, so it will finish before iterating on the result
# otherwise, it could reprocess files that were allready updated
foreach ($file in (Get-ChildItem -Path 'C:\' -Recurse -Filter 'demo.txt' -File -ErrorAction SilentlyContinue)) {
# -replace uses regex, so surround the search string with '\b' boundary markers in order to do a whole-word search
$content = (Get-Content -Path $file.FullName -Raw -Force) -replace '\bdemo\b', 'demo997182625'
# test if the content now has the new value (again, use '\b' boundary markers)
if ($content -match '\bdemo997182625\b') {
# save the updated file
$content | Set-Content -Path $file.FullName -Force
$found++
}
else {$notfound++}
}
Write-Host "Changed: $found"
Write-Host "Not Changed: $notfound"
P.S. If your search string contains characters that in regex have special meaning (see table below), you need to escape these with a backslash when using regex operators -replace and -match.
Special Characters in Regex
Char
Description
Meaning
\
Backslash
Used to escape a special character
^
Caret
Beginning of a string
$
Dollar sign
End of a string
.
Period or dot
Matches any single character
|
Vertical bar or pipe symbol
Matches previous OR next character/group
?
Question mark
Match zero or one of the previous
*
Asterisk or star
Match zero, one or more of the previous
+
Plus sign
Match one or more of the previous
( )
Opening and closing parenthesis
Group characters
[ ]
Opening and closing square bracket
Matches a range of characters
{ }
Opening and closing curly brace
Matches a specified number of occurrences of the previous