# ls -al
total 16
drwxrwxrwx 2 root sys 96 Jun 13 18:12 .
drwxrwxrwt 14 root root 8192 Jun 13 18:12 ..
-rw-rw-rw- 1 root sys 0 Jun 13 18:12 1.AAA
-rw-rw-rw- 1 root sys 0 Jun 13 18:12 2.AAA
-rw-rw-rw- 1 root sys 0 Jun 13 18:12 3.AAA
skledi1@root[/tmp/bbb]
# ls *.AAA | sed 's/\(.*\).AAA$/mv "&" "\1.BBB"/' | sh
edi@root[/tmp/bbb]
# ls -al
total 16
drwxrwxrwx 2 root sys 96 Jun 13 18:13 .
drwxrwxrwt 14 root root 8192 Jun 13 18:13 ..
-rw-rw-rw- 1 root sys 0 Jun 13 18:12 1.BBB
-rw-rw-rw- 1 root sys 0 Jun 13 18:12 2.BBB
-rw-rw-rw- 1 root sys 0 Jun 13 18:12 3.BBB