I use since more than 20 years Total Commander (shareware) for file/folder renaming tasks which makes it possible with its built-in multi-rename tool to easily rename files and folders with just a few clicks on which the results can be viewed before really running the multi-rename and which even supports undo after having done the multi-rename. Well, in real I use Total Commander for nearly all file management tasks.
But it was interesting to develop the code for this very special file renaming task with all the limitations Windows command processor has because of not being designed for such tasks.
@echo off
setlocal EnableExtensions DisableDelayedExpansion
for /F "eol=| delims=" %%I in ('dir /A-D-H /B 2^>nul ^| %SystemRoot%\System32\findstr.exe /R /C:"19[89][0123456789]" /C:"20[012][0123456789]"') do call :RenameFile "%%I"
endlocal
goto :EOF
:RenameFile
set "FileName=%~n1"
setlocal EnableDelayedExpansion
set "Year=1980"
:YearLoop
set "NewName=!FileName:%Year%=(%Year%)!"
if "!NewName!" == "!FileName!" (
if %Year% == 2029 goto ExitSub
set /A Year+=1
goto YearLoop
)
if "!FileName:(%Year%)=!" == "!FileName!" ren "%~1" "!NewName!%~x1"
:ExitSub
endlocal
goto :EOF
FOR executes the following command line in a separate command process started in background with cmd.exe /C:
dir /A-D-H /B 2>nul | C:\Windows\System32\findstr.exe /R /C:"19[89][0123456789]" /C:"20[012][0123456789]"
DIR outputs with the used options all names of non-hidden files in current directory with just file name + extension and without file path. An error message output in case of current directory does not contain any non-hidden file is suppressed by redirecting it from handle STDERR to device NUL with 2>nul.
The file names output by DIR are redirected with | to handle STDIN of command FINDSTR which searches case-sensitive with two regular expression interpreted search strings for four digits in range 1980 to 1999 or in range 2000 to 2029. There is no check made if a match of a four digit number is part of a larger number like 12000 or 19975. And there is no check made if there are already round brackets around the four digit number.
FINDSTR interprets also ¹, ², ³ as digit on using [0-9] which is the reason for using [0123456789] to really match only any of those 10 digit characters. Please read for more details about FINDSTR the articles SS64 - FINDSTR and What are the undocumented features and limitations of the Windows FINDSTR command?
FINDSTR outputs all file names containing four digits in range 1980 to 2029 to handle STDOUT of background command process.
Please read the Microsoft article about Using Command Redirection Operators for an explanation of 2>nul and |. The redirection operators > and | must be escaped with caret character ^ on FOR command line to be interpreted as literal characters when Windows command interpreter processes this command line before executing command FOR which executes the embedded dir command line in a separate command process started in background.
FOR captures those lines and processes them line by line. The default for option eol= (end of line) is a semicolon and so FOR would ignore all file names starting with a semicolon. For that reason eol=| is specified because a vertical bar cannot be used in a file name and so all captured file names are processed by FOR.
FOR would split up each file name on spaces/tabs by default and assigns only the first substring (token) to specified loop variable I. This splitting behavior is disabled by using delims= which defines an empty list of delimiters. tokens=* is not the same as this results in removing leading spaces from the file names. File names can start with one or more spaces although this is very unusual.
A file name can contain also exclamation marks ! which must be also taken into account on using delayed environment variable expansion. Each file name is passed to a subroutine for further processing it.
A loop is used to replace all occurrences of year assigned to loop variable Year by the year in round brackets until new file name is different to current file name because the substitution was indeed positive for searched string. for /L %%J in (1980,1,2029) do ... was not used as this loop can't be exited once having found the right year in file name.
After having found the year in file name it is checked if this year is not already embedded in parentheses to avoid renaming a file with name home vid (1987).mov to home vid ((1987)).mov. So for example home video 1998.avi is renamed finally to home video (1998).avi.
A file name containing two numbers with four or more digits is also not processed correct as this code can't find out what is the year in such a file name.
This batch code is not really fast, but it should work with the listed limitations.
For understanding the used commands and how they work, open a command prompt window, execute there the following commands, and read entirely all help pages displayed for each command very carefully.
call /?dir /?echo /?endlocal /?findstr /?goto /?if /?ren /?set /?setlocal /?
See also Where does GOTO :EOF return to?
PS: File names with ( or ) in name make processing them with a batch file very often more difficult as in this case the file name must be always enclosed in double quotes like for file names containing a space character because of ( and ) have also a special meaning for Windows command processor cmd.exe as it can be seen on code above. See also How does the Windows Command Interpreter (CMD.EXE) parse scripts?
