How can you tell V7 dgn files apart from V8?

Question

I have a lot of dgn files and don&rsquo;t know which are V7 and which are V8. Is there a way to quickly and easily tell them apart? I would hate to have to go through and open them up individually.

Kevin van Haaren · Answer

Do you know how to use PowerShell? I wrote a PowerShell function that will give a file's magic number ( https://en.wikipedia.org/wiki/Magic_number_(programming)#In_files) and if it recognizes the magic number the file type. It can recognize V7 and V8 files. 
 The function is on GitHub here: Get-MagicNumber on GitHub 
 Put that function in a file, then open PowerShell and do: 
 . filename.ps1 
 where the first character is period, then space, then the name of the ps1 file you put the function in. 
 Once you've done that you can cd to your folder of files and do the following: 
 dir *.dgn -recurse -file | Get-MagicNumber | Format-Table File,FileType

Where:
 -recurse means to get all *.dgn files in the current folder and sub-folders
 -file means only return info about files
 
 You can also use the Export-Csv command instead of Format-Table to send the info to a CSV file instead of the screen.

David Trejo-Rodriguez · Answer

To add to Bob's suggestions the following article details a possible workflow: 
 Upgrade V7 files to V8 
 John Doe said: I have a lot of dgn files and don’t know which are V7 and which are V8. Is there a way to quickly and easily tell them apart? I would hate to have to go through and open them up individually.

Lorys · Answer

John Doe said: Bentley's DGN iFilter is not compatible with pre-V8 DGN 
 ok , the batch convert process should not create duplicates it replaces the existing file just from the autoconversion . 
 Alternatively just use a batch processor with script to open and then filedesign and if configured workspace properly it will convert V7 to V8 on the fly. 
 The batch processor will open and process faster in sort a of non graphic mode faster than manual..( not exactly right description but good enough lay explanation) 
 you can still use your python list to cut down which files to add to the batch.. personally I would just work my way through all the files in bulk say by directory by directory after everyone has gone home or over night ... just run it and walk away... 
 A million dgns , really? 
 ok say 2 seconds per file > 278 hours > at 12 hours per day = 23 days so roughly 3 - 4 weeks , but this could also be done by several people as long as they do different folders each you keep track of who did what folders. 
 do a test with 100 drawings first and time it then decide if you can expand it and use a few user pcs they dont even have to be there just run over night.. or weekend ...

How can you tell V7 dgn files apart from V8?

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