More

  ARM Give a man a fire and he's warm for a day, but set fire to him and he's warm for the rest of his life (Terry Pratchett, Jingo)
More

cp -a fs/ext{2,69}
cp -a include/linux/ext{2,69}_fs.h
cp -a include/linux/ext{2,69}_fs_i.h
cp -a include/linux/ext{2,69}_fs_sb.h
for i in fs/ext69/* include/linux/ext69*; do
vi '-cse ext|%s/(ext|EXT)2/\169/g|x' $i;
done
vi '-c/EXT/|y|pu|s/2/69/|s/Second/FUBAR/|x' fs/Config.in
vi '-c/ext2/|y|pu|s/ext2/ext69/g|//|y|pu|&g|//|y|pu|&g|//|y|pu|&g|x' \
include/linux/fs.h

had done the trick last time I needed something like that, but that was long
time ago...

- Al Viro explaining some simple commands on linux-kernel