single line batch rename in terminal/shell

ls fail*.jpg
fail1.jpg fail2.jpg fail3.jpg fail389.jpg failCat.jpg
to batch rename fail*.jpg to win*.jpg:

1. cd to desired directory
2. preview the files that will be effected:
   ls fail*.jpg | awk '{print("mv "$1" "$1)}' | sed 's/fail/win/2'
   which will show you something like this:
   mv fail1.jpg win1.jpg
mv fail2.jpg win2.jpg
mv fail3.jpg win3.jpg
mv fail389.jpg win389.jpg
mv failCat.jpg winCat.jpg
   this is just a preview - nothing has been changed yet.
3. ready to commit to a batch rename?
   ls fail*.jpg | awk '{print("mv "$1" "$1)}' | sed 's/fail/win/2' | /bin/sh
4. ls win*.jpg
win1.jpg win2.jpg win3.jpg win389.jpg winCat.jpg