How to change/remove the file extensions of a group of files

I have a bunch of .txt files in a directory, and I want to be able to find these files and strip the extension from the file name.

I can find the files using:

$ find . -maxdepth 1 -type f -name "*.txt"
./0test.txt
./1test.txt
./2test.txt
./3test.txt
./4test.txt
./5test.txt
./6test.txt
./7test.txt
./8test.txt
./9test.txt

I then tried to use sed command to remove the ".txt" extension, like:

find . -maxdepth 1 -type f -name "*.txt" | sed "s/\.txt$//"

But I just get the file names listed without their extensions, and the actual file names remain unchanged.

So how do you actually change the file names themselves?

How about this in bash

for v in *.txt ; do mv "$v"  "$(basename "$v" .txt)"; done

$ in a regular expression matches the end of a string, you can't match characters after that, only before.

Also . needs to be escaped to stop it from having its special meaning (any character).

So:

find . -maxdepth 1 -type f -name "*.txt" | sed "s/\.txt$//"

If you're trying to rename the files, then you can use the same regular expression substitution with the perl-based rename command

rename "s/\.txt$//" *.txt

(you don't need find when all the files are in a single directory level), or a simple shell loop with mv:

for f in *.txt; do mv -n -- "$f" "${f%.txt}"; done