For changing all .htm files in directory to .html files

sriram@ubuntu:~/scripts$ for file in *.htm; do mv "$file"  ${file%.htm}.html; done
sriram@ubuntu:~/scripts$ ls
10.html  2.html  4.html  6.html  8.html  test
1.html   3.html  5.html  7.html  9.html
sriram@ubuntu:~/scripts$