PowerShell - How to Update a file based on content from another file - regex

Question

I've searched all over including here at StackOverFlow and I cannot seem to find the solution I am needing help with. Here is my issue.
Lets say in File1.txt I have the following (no spaces between each line)
\\Serv02\LOC6\Client\726C30\032383\2200018023.pdf
\\Serv02\LOC6\Client\726C30\032383\2200718091.pdf
\\Serv02\LOC6\Client\726C30\030684\2300309040.pdf
\\Serv02\LOC6\Client\726C30\031274\2300429971.pdf
File2.txt will have the same information, however, I am needing to add a 1 right before the .pdf for each one (within file2.txt)
Example:
\\Serv02\LOC6\Client\726C30\032383\22000180231.pdf
I can easily update file2.txt using a RegEx statement, however it's only updating the contents based on that RegEx statement.
File2.txt will have a lot more data in it than file1.txt (more of the exact type of information). I am only needing to update file2.txt adding in the 1 right before .pdf BASED on what is in file1.txt
Here is the code I am using but as you can see it does not read file1.txt at all, I'm just using a RegEx statement to update file2.txt adding in the 1 before .pdf (the code below works to add in the 1 before .pdf, but I'm not iterating through file1.txt)
clear-host
set-location c:\temp
$File = "C:\Temp\file1.txt"
$FileZ = "C:\Temp\file2.txt"
$File2 = (Get-ChildItem $fileZ) | Select -ExpandProperty BaseName
$regex01 = '(\\Serv02\LOC6\Client\726C30\\d{1,6}\\d{1,10})(.pdf)$'
get-content $fileZ | % { $_ -replace $regex01, '${1}1${2}' -join "`r`n" } | out-file -Encoding default "c:\Temp\$File2.txt"
start-sleep -Seconds 2
$NewMRC = Get-ChildItem "$file2.txt" | Select -ExpandProperty Name
Get-ChildItem $NewMRC | rename-item -NewName {$_.Name -replace ".txt",".MRC2"}
If file1.txt had another line that didn't match up to the RegEx as shown above, file2.txt would not be updated with that line
\\Serv03\LOC7\Client\780D30\031456\8675309123.pdf
I hope I have explained this well enough. I'm not new to PowerShell but I am far from an expert. Any assistance is greatly appreciated.

Answer 1

I've modified your code as follows. The approach is read the content of File1.txt and store it in a variable. Then iterate on each line of File2.txt to check it against the regex as well as if that line is present in file1 content. If yes then replace it with whatever you want. Output this to a .tmp file in append mode. Once all the lines in File2.txt are processed, then replace it with .tmp file.
clear-host
set-location c:\temp
$File = "file1.txt"
$FileZ = "file2.txt"
# PS2
$File1 = get-content $File | Out-String
# PS3
# $File1 = get-content $File -Raw
$File2 = (Get-ChildItem $fileZ) | Select -ExpandProperty BaseName
if( test-path "$File2.tmp" ) { remove-item "$File2.tmp" }
$regex01 = '(\\\\Serv02\\LOC6\\Client\\726C30\\\d{1,6}\\\d{1,10})(.pdf)$'
get-content $fileZ |% {
$line = $_
$find = $line -replace '\\','\\'
if ( ($line -match $regex01) -AND ( $File1 -match $find ) ) {
$line -replace $regex01,'${1}1${2}' -join "`r`n"
} else {
$line
}
} | out-file "$File2.tmp" -append
remove-item "$File2.txt"
rename-item "$File2.tmp" "$File2.txt"
#start-sleep -Seconds 2
#$NewMRC = Get-ChildItem "$file2.txt" | Select -ExpandProperty Name
#Get-ChildItem $NewMRC | rename-item -NewName {$_.Name -replace ".txt",".MRC2"}
Notes:
The last 3 lines of your code doesn't seem to be related to your problem statement. So I've commented those lines.
$find = $line -replace '\\','\\': We are replacing single backslash \ with double backslash \\. But in the first parameter to -replace it must be escaped and in second param it must NOT be. So, even though they look same, they are interpreted differently.

Answer 2

One way to do this: Retrieve file content of first file into an array, then retrieve content of second file. For each line in second file: If first file's content has a line matching the current line, output modified line; otherwise, just output the current line.
$pattern = '(\\{2}(?:[^\\]+\\)+)([^\\\.]+)(\.pdf)'
$file1Content = Get-Content "file1.txt"
Get-Content "file2.txt" | ForEach-Object {
if ( $file1Content -contains $_ ) {
$_ | Select-String $pattern | ForEach-Object {
"{0}{1}1{2}" -f
$_.Matches[0].Groups[1].Value,
$_.Matches[0].Groups[2].Value,
$_.Matches[0].Groups[3].Value
}
}
else {
$_
}
}
First match group ($_.Matches[0].Groups[1].Value) is \\servername\sharename\path, second match group is filename without extension, and third match group is the file extension.