Powershell replace special characters string in all files in directory path

powershellreplacespecial characters

I'm trying to create a 'find and replace' script for the website our company just acquired. Right now, I just want to use it to replace their address and phone number with
ours, but I'll likely need to customize it in the future to replace or update other stuffs.

So far, what I got is:

(Get-Content C:\Scripts\Test.txt) | 
Foreach-Object {$_ -replace "\*", "@"} | 
Set-Content C:\Scripts\Test.txt

which I got from The Scripting Guy 😛

However, I need help customizing it. What I need it to do is:

Do it for all files in a directory and all sub-directories, not just one file. The website as far as I can tell is a collection of *.php files
Handle special characters that appear in some addresses, like copyrights (©) pipes (|) commas (,) and periods (.)

Here's the exact string I'm trying to replace (as it appears in the .php's):

Since this could be the first tool in my powershell toolbox, any explaining of what you're adding or changing would greatly help me understand what's going on.

Bonus points:

Any way to log which files were 'find-and-replace'ed?

Best Answer

My suggestion would be to use a ForEach loop. I don't see the need for a function in this case, just have the code in your ForEach loop. I would define a string to search for, and a string to replace with. When you perform the replace make sure that it is escaped. Something along these lines:

$TxtToFind = "<p>&#169;Copyright 2012 GSS | 48009 Fremont Blvd., Fremont, CA 94538 USA</p>"
$UpdatedTxt = "<p>&#169;Copyright 2014 | 1234 Somenew St., Houston, TX 77045 USA</p>"
$Logfile = "C:\Temp\FileUpdate.log"
ForEach($File in (GCI C:\WebRoot\ -Recurse)){
    If($File|Select-String $TxtToFind -SimpleMatch -Quiet){
        "Updating lines in $($File.FullName)" |Out-File $Logfile -append
        $File|Select-String $TxtToFind -SimpleMatch -AllMatches|Select -ExpandProperty LineNumber -Unique|Out-File $Logfile -append
        (GC $File.FullName) | %{$_ -replace [RegEx]::Escape($TxtToFind),$UpdatedTxt} | Set-Content $File.Fullname
    }
}

Related Solutions

Javascript – How to replace all occurrences of a string in JavaScript

As of August 2020: Modern browsers have support for the String.replaceAll() method defined by the ECMAScript 2021 language specification.

For older/legacy browsers:

str = str.replace(/abc/g, '');

In response to comment:

var find = 'abc';
var re = new RegExp(find, 'g');

str = str.replace(re, '');

In response to Click Upvote's comment, you could simplify it even more:

function replaceAll(str, find, replace) {
  return str.replace(new RegExp(find, 'g'), replace);
}

Note: Regular expressions contain special (meta) characters, and as such it is dangerous to blindly pass an argument in the find function above without pre-processing it to escape those characters. This is covered in the Mozilla Developer Network's JavaScript Guide on Regular Expressions, where they present the following utility function (which has changed at least twice since this answer was originally written, so make sure to check the MDN site for potential updates):

function escapeRegExp(string) {
  return string.replace(/[.*+\-?^${}()|[\]\\]/g, '\\$&'); // $& means the whole matched string
}

So in order to make the replaceAll() function above safer, it could be modified to the following if you also include escapeRegExp:

function replaceAll(str, find, replace) {
  return str.replace(new RegExp(escapeRegExp(find), 'g'), replace);
}

Bash – How to do a recursive find/replace of a string with awk or sed

find /home/www \( -type d -name .git -prune \) -o -type f -print0 | xargs -0 sed -i 's/subdomainA\.example\.com/subdomainB.example.com/g'

-print0 tells find to print each of the results separated by a null character, rather than a new line. In the unlikely event that your directory has files with newlines in the names, this still lets xargs work on the correct filenames.

\( -type d -name .git -prune \) is an expression which completely skips over all directories named .git. You could easily expand it, if you use SVN or have other folders you want to preserve -- just match against more names. It's roughly equivalent to -not -path .git, but more efficient, because rather than checking every file in the directory, it skips it entirely. The -o after it is required because of how -prune actually works.

For more information, see man find.

Best Answer

Related Solutions

Javascript – How to replace all occurrences of a string in JavaScript

Bash – How to do a recursive find/replace of a string with awk or sed

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