...

Warning
Make sure you have spaces inside the [] otherwise bash will sit spit the dummy!

Code Block

if [ $? -eq 0 ]; then
  echo "Success"
else
  echo "Failure"

...

Code Block

if [ $? -ne 0 ]; then
  echo "Failure"
else
  echo "Success"

Conditionally Exit

Code Block

# Use braces
CARLA_TARBALL=`ls ${CARLA_ROOT}/Distd/*.tar.gz 2> /dev/null` || { echo "Carla tarball not found, exiting." ; exit 1; }

Conditionally Set Variables

Code Block

: ${var=value}

This one is obscure....<TODO> explain!

Code Block

language	bash
theme	RDark
title	Set if not defined OR set to the empty string
collapse	true

: ${var:=value}

...