Question

Note: There is no need to use batch per say, but I am just familiar with batch, Powershell would be better I imagine, so if there are easier solutions for this problem in powershell, please shout!

I have the arduous task of testing our DR backups for all our clients, that is, mounting ShadowProtect Snapshots latest incremental, writing and reading a file, them unmounting the image. The actual ShadowProtect part of batch is fairly simple but I would like to design a batch that can automate this.

Essentially my question is:

How in a batch file can I firstly, enumerate files in a folder, and then place a specific part of a given filename into a variable?

Reason being ShadowProtect incrementals have a naming convention such like:

SERVERNAME_DRIVELETTER_b00X_i000x           - whereby b = base image, i = incremental number

I need to mount the latest incremental image, therefore need to parse the folder and find the latest incremental image, based on the number following the i in the filename.

Is this possible in batch?

Thanks!

Answer 1

Something like this should work:

@echo off

setlocal EnableDelayedExpansion

for /f "delims=_ tokens=1-4" %%f in ('dir /b *_*_*_*') do (
  set servername=%%f
  set driveletter=%%g
  set base_image=%%h
  set increment=%%i
)

echo !servername!
echo !driveletter!
echo !base_image!
echo !increment!

endlocal

If you have several matching files and want to do something with all of them, you need to put the processing code inside the loop.

Edit:

• for /f: process either a file or the output of a command enclosed in single quotes
• delims=_: fields in the processed content are separated by underscores
• tokens=1-4: assign the first four tokens to the parameters %%f through %%i (first parameter is the one given in the for statement)
• dir /b *_*_*_*: list all file where the name contains at least 3 underscores with just their file name (the output of this command is processed by the for loop)
• setlocal EnableDelayedExpansion: expand variables at run time (otherwise assigning the parameters to variables wouldn’t work)

For further details see help for and help dir.