Windows batch to add prefix to file names, why added twice?

windows file batch-file batch-processing prefix
Marco Demaio picture Marco Demaio · Jan 15, 2015 · Viewed 21.7k times · Source

In order to add a simple "hello" prefix to all pdf files in a folder I'm using this batch file:

FOR %%F IN (*.pdf) DO (RENAME "%%F" "hello%%F")

Saved this into a "rename.bat" file and placed it into the folder I need the files to be renamed. Then I just double click on "rename.bat".

This almost works but the 1st file gets the prefix added twice.

Let's say in the folder I have: A.pdf, B.pdf, C.pdf, they get converted into:

  • hellohelloA.pdf
  • helloB.pdf
  • helloC.pdf,

Do you know what's wrong in the batch file?

I noticed it always does this when files are more than one. It works ok when there is only one file in the folder, but it is not very useful :-).

Answer

Alex K. picture Alex K. · Jan 15, 2015

/f removes the issue of recapturing an existing file:

FOR /f "delims=" %%F IN ('DIR /a-d /b *.pdf')  DO (RENAME "%%F" "hello%%F")

Related questions

How to do something to each file in a directory with a batch script

How do you iterate over each file in a directory with a .bat or .cmd file? For simplicity please provide an answer that just echoes the filename or file path.

Read More
How to check command line parameter in ".bat" file?

My OS is Windows Vista. I need to have a ".bat" file where I need to check if user enters any command-line parameter or not. If does then if the parameter equals to -b then I will do something otherwise …

Read More
How to make a batch file execute a reg file

I have the following code @echo off file.reg pause This works but when the batch file is elevated I get an error saying that it cannot find the file. does any one know what I am doing wrong.

Read More