In addition to what everyone else has said about env(1), there is the fact that Korn derived shells also supports some of the same features.
env VAR1=foo VAR2=bar random-command VAR1=foo VAR2=bar random-command If running a Korn-like shell (ksh, bash, zsh), both would set the envvars VAR1 and VAR2 to those values. (Note: I don't *think* earlier Bourne shells support that, but I may be misremembering when the feature was introduced. It was likely before even my time.) However, C-shell derived do not, you must use the env(1) command. But, env(1) does also offers the -i and -u flags to initialize and unset envvars. I use -u a lot during dev/testing to make sure scripts I write work correctly in various combinations. mrc
