CODE EXAMPLE FOR SHELL

bash append file

# syntax (note: the -e switch is to allow for backslash escapes)
echo -e "<string-to-append>" >> <file-to-append-to>

# example 
echo -e "Hello there, new line!" >> RandomWorld.txt

# -----------------------------------------------
# In order to see the effect of -e, append the following string:
"Hello there,
 new line!"