Defining a variable with or without export

Question

What is export for?

What is the difference between:

export name=value

and

name=value

Answer 1

Here's yet another example:

VARTEST="value of VARTEST" 
#export VARTEST="value of VARTEST" 
sudo env | grep -i vartest 
sudo echo ${SUDO_USER} ${SUDO_UID}:${SUDO_GID} "${VARTEST}" 
sudo bash -c 'echo ${SUDO_USER} ${SUDO_UID}:${SUDO_GID} "${VARTEST}"'  

Only by using export VARTEST the value of VARTEST is available in sudo bash -c '...'!

For further examples see:

• http://mywiki.wooledge.org/SubShell

• bash-hackers.org/wiki/doku.php/scripting/processtree