Skip to main content

Text file compare using PowerShell



PowerShell is able to compare text file easily.

Technet article at the link below suggest using Get-FileHash cmdlet to compare whether files are different or not.


Below code is taken from Technet link above that shows how to use the Get-FileHash method.

PS C:\> (Get-FileHash $fileA).hash  -ne (Get-FileHash $fileC).hash



    True



PS C:\> (Get-FileHash $fileA).hash  -ne (Get-FileHash $fileB).hash



   False

The output of the cmdlet is either True or False. True if the file is the not same with the other file, false if file is the same with the other file.

It is just true or false to check whether both files are the same or not the same.

But if files are not the same, how to check which lines or contents does not match with the other file?

In my own point of view if there is a need to check the contents, then Excel VBA will come in handy.

Link below uses VBA code to check or compare row by row.


Comparing row by row is only applicable if the files need to compare line by line and data in one line doesn't need to be compared to other data on other lines.

If the file doesn't have a consistent pattern, then it's quite difficult to compare.

Organizing the data for consistency is quite important or else it will be difficult or hard to manage once the data grows bigger and bigger.

If quite paranoid on your system and wants to monitor some particular folders what had changed over the time. Then a baseline reference is needed.

For example, during the installation of a single computer you get the baseline file for c:\Windows\System32 for all ".dll" files.

As days or months passes by you never install anything and want to check whether some new ".dll" files has been added.

You can compare the baseline text file to the current files on your system.

Of course there might be some difference since Microsoft or Windows update your system either to patch vulnerabilities or improve the system.

I think it's good to list out and compare the ".dll" files. If some unknown dll files or extra dll files during comparison comes out; which is quite suspicious then delete the file. Or backup the file before deleting.

If something goes wrong then copy over the file and check whether the system will get back to normal; but if the system goes smoothly then delete the backup “.dll” file and run system file checker to scan the system for any issues. Also run anti-virus or anti-malware software to make sure the system is not infected with any kind of virus or malware.

There are a lot of ways to do things as well as there a lot of reasons why we need to do things, so which ever method that will get the job done easily in a time efficient way should be the best choice of getting things done.

Cheers.. till next time..

Comments

Popular posts from this blog

Notepad++ convert multiple lines to a single line and vice versa

Notepad++ is an awesome text editing tool, it can accept regex to process the text data. If the data is in a “.csv” format or comma separated values which is basically just a text file that can either be opened using a text editor, excel or even word. Notepad++ can process the contents of the file using regex. Example if the data has multiple rows or lines, and what is needed is to convert the whole lines of data into a single line. Notepad++ can easily do it using regex. However, if the data is on a single line and it needs to be converted into multiple lines or rows then regex can also be used for this case. Here’s an example on how to convert multiple rows or lines into a single line. Example data: Multiple rows, just a sample data. Press Ctrl+H, and  on "Find what" type: [\r\n]+ and on "Replace with" type with: , (white space) --white space is needed if need to have a space in between the data. See image below, "Regular Expression" must be se

WMIC get computer name

WMIC get computer model, manufacturer, computer name and  username. WMIC is a command-line tool and that can generate information about computer model, its manufacturer, its username and other informations depending on the parameters provided. Why would you need a command line tool if there’s a GUI to check? If you have 20 or 100 computers, or even more. It’s quite a big task just checking the GUI to check the computer model and username. If you have remote computers, you need to delegate someone in the remote office or location to check. Or you can just write a batch file or script to automate the task. Here’s the code below on how get computer model, manufacturer and the username. Open an elevated command prompt and type:     wmic computersystem get "Model","Manufacturer", "Name", "UserName" Just copy and paste the code above, the word “computersystem” does not need to be change to a computer name. A

How to check office version from command line

The are quite a few ways to check office version it can be done via registry, PowerShell or VBScript and of course, good old command line can also do it. Checking Windows office version whether it is Office 2010, Office, 2013, Office 2016 or other version is quite important to check compatibility of documents; or just a part of software inventory. For PowerShell this simple snippet can check the office version: $ol = New-Object -ComObject Excel.Application $ol . Version The command line option will tell you where’s the path located; the result will also tell whether office is 32-bit, 64-bit and of course the version of the office as well. Here’s the command that will check the office version and which program directory the file is located which will tell whether it’s 32-bit or 64-bit. Command to search for Excel.exe: DIR C:\ /s excel.exe | find   /i "Directory of"  Above command assumes that program files is on  C: drive. Sample Outpu