cmd – How to change extension from en.srt to .srt in command prompt – Stack Overflow

for %%a in (.*.jpg) do

The code above will store every jpg picture’s name in %%a, but it stores the full name with the file extension, for example “Q.jpg”.

I’m using a cmd utility for resizing images,

resize /width:100 %%a %%a.jpg

It will resize “Q.jpg” and then name it to “Q.jpg.jpg”, as you can see the extension is now a part of file name!!!

I want to avoid it.

A simply though clumsy method is to rename the files twice – first remove .srt, then change .en to .srt (given that there are no other files *.en):

ren "*.en.srt" "*." & ren "*.en" "*.srt"

A more elegant solution is the one provided by user Mofi in his comment:

@for /F "eol=| delims=" %I in ('dir "*.en.srt" /B /A:-D 2^> nul') do @for %J in ("%~nI") do @ren "%~I" "%~nJ%~xI"

In a batch-file this code would look similar to this (note the necessarily doubled %-signs):

@echo off
rem // Loop through all matching files:
for /F "eol=| delims=" %%I in ('dir "*.en.srt" /B /A:-D 2^> nul') do (
    rem /* There are `~`-modifiers for `for` meta-variables that allow to split file names:
    rem    `~n` returns the base name, so the (last) extension becomes removed;
    rem    `~x` returns the extension (including the leading `.`);
    rem    therefore, `%%~nI` is the original file name with `.srt` removed, hence
    rem    ending with `.en`, and `%%~xI` is the original extension `.srt`;
    rem    another loop is used to also split off `.en` from `%%~nI`: */
    for %%J in ("%%~nI") do (
        rem /* Now `%%~J` returned the same as `%%~nI`, but `%%~nJ` removes `.en`;
        rem    so finally, rename the file to `%%~nJ` plus the original extension `.srt`: */
        ren "%%~I" "%%~nJ%%~xI"
    )
)

Following the thorough thread How does the Windows RENAME command interpret wildcards? on Super User, I found out that there is a way using a single ren command:

ren "*.en.srt" "?????????????????????????????????????????.srt"

However, you need to make sure to have enough ?, namely as many as there are characters in longest matching file name without .en.srt; otherwise, file names become truncated. You can avoid truncation by replacing the same sequence of ? instead of *, so longer file names are not renamed at all:

ren "?????????????????????????????????????????.en.srt" "?????????????????????????????????????????.srt"

Anyway, this only works when the original file names do not contain any more . besides the two in .en.srt; otherwise, everything behind the first . becomes removed and (finally replaced by srt).

I need to change files extension in folders and subfolders by creating bat file

Example

File1.txt
File2.txt
………
FileN.txt

Should be renamed to

File1.jpg
File2.jpg
File3.jpg
………
FileN.jpg

inside the folder and in subfolders.

Additionally then

File1.txt
File2.txt
.........
FileN.txt

should be removed

I have tried for /d /r %f in (.) do ren "%f*.txt" "*.jpg" but it didn’t worked for me

I have tried a lot, but the assoc command doesn’t work for me.
When I type

assoc .html=txtfile

the command seems to have been executed as expected. When I check the extension and the associations the .html association has changed to txtfile. But normally it should mean, that the .html files are opened with notepad from now, shouldn’t it? Because that is not the case!
I also tried to restart my PC after that.
What have I done wrong?