The Batch file below do what you want, but if the file to convert is large this method is slow...
@echo off
setlocal EnableDelayedExpansion
for /F "delims=" %%a in (%1) do (
set "line=%%a"
for %%b in (A B C D E F G H I J K L M N O P Q R S T U V W X Y Z) do (
set "line=!line:%%b=%%b!"
)
echo !line!
)
To use this program, place the name of the file in the first parameter. For example, if this Batch file is called TOUPPER.BAT:
toupper abc.txt
Note that this program eliminate empty lines and any exclamation mark existent in the file. These limitations may be fixed if needed, but the program becomes even slower...
Antonio