CODE EXAMPLE FOR SHELL

linux find and remove bom from files

sed '1s/^xEFxBBxBF//' < orig.txt > new.txt
You can also overwrite the existing file with the -i option:

sed -i '1s/^xEFxBBxBF//' orig.txt
If you are using the BSD version of sed (eg macOS) then you need to have bash do the escaping:

 sed $'1s/xefxbbxbf//' < orig.txt > new.txt