Setting a variables for one command only

If you want to set a variable for one command only, you can always write the variable setting first, immediately followed by the simplecommand (don't write any ; after the assignment). This will result in the variable being set for that command only, but keeping the old value (if it had one) after the command has been executed. As an example, if you execute the code

MANPATH=/usr/man:/usr/local/man man test

will only look for the manual for test in directories /usr/man and /usr/local/man. This regardless of what value MANPATH had before the call.