TIL about the rename command utility. It allows us to rename files using a Perl Common Regular Expression. Suppose we have the following files:

$ ls
temp1.txt	temp2.txt	temp3.txt

Now we want to rename our files from temp to final, but are not really sure how to craft our regular expression. In this case we can use the -n flag:

$ rename -n 's/temp/final/' *.txt
'temp1.txt' would be renamed to 'final1.txt'
'temp2.txt' would be renamed to 'final2.txt'
'temp3.txt' would be renamed to 'final3.txt'

And when we are ready:

$ rename 's/temp/final/' *.txt
$ ls
final1.txt	final2.txt	final3.txt

For MacOSX users rename can be installed through: brew install rename. The tldr tool does a great job summarizing the common use cases, but as always man rename explains the entire scope.