Why extglob except breaking except condition?

Question

I run in Debian 8.1, GNU bash, version 4.3.30(1)-release (x86_64-pc-linux-gnu) and Lenovo G50-30 with 500 GB SSD and 8 GB flash memory:

shopt -s extglob
cp -         


        

Answer 1

Try removing the backslash (I am adding echo for test purposes):

shopt -s extglob
echo cp -r !(Backups.backupdb) /home/masi/Documents/

It works in my environment (GNU bash, version 4.3.30, OS X)