Guide: batch append suffix to filename in Bash

Batch appending to filenames is a common task. The following is my preferred method, but there are many other good ones.¹ Note that prepending works much the same way.

for name in *.extension
do
mv "$name" "${name%.extension}-suffix.extension"
done

This is a natural extension of a single line move command. The extension is removed via the % and replaced with suffix + extension. (In Bash parameter expansion, % subtracts a suffix from the pattern non-greedily. For more information, see man bash under Parameter Expansion. (Search for ${parameter%word}.))