How to delete the last character in a line?

This is simple and without any description, here is the regex.

# echo "This is last character" |  sed 's/.$//g' 
This is last characte

SED & TR uses

Here are the quickies for my very own sed and tr:

To replace "NEWLINE" (\n) with "comma" (,)

cat filename | tr '\n' ','

To find "tree" and replace with "plant" in a file (using sed):

sed -i 's/tree/plant/g' filename