xxxxxxxxxx
# Save suffixed file into a new file
sed -e 's/$/suffix/' file > file.new
# Edit file and overwrite with prefixed text
sed -i -e 's/$/suffix/' file
# Save prefixed file into a new file
sed -e 's/^/prefix/' file > file.new
# Edit file and overwrite with prefixed text
sed -i -e 's/^/prefix/' file