How to set environment variable only for script time?

Question

On Linux (Ubuntu 11.04) in bash, is it possible to temporarily set an environment variable that will be different from a regular variable for the duration of the script? For example, in a shell script, creating an application that saves in HOME portable, temporarily installing HOME in a folder in the current working directory, and then launching the application.

Answer 1

VAR1=value1 VAR2=value2 myScript args ... 

Answer 2

 env VAR=value myScript args ... 

Answer 3

Just put

 export HOME=/blah/whatever 

at the point in the script where you want this to happen. Since each process has its own set of environment variables, this definition automatically ceases to have any value when the script exits (and with it an instance of bash that has a modified environment).