I would code it like this: 
do { 
  local $ENV{FOO} = 'bar';
  system($command);
};

[download]
This gives you the temporary-env-value semantics of "FOO='bar' $command", yet doesn't assume that the user's shell has said semantics (Win32's cmd.exe certainly doesn't, for example).
--Stevie-O 
$"=$,,$_=q>|\p4<6 8p<M/_|<('=>
.q>.<4-KI<l|2$<6%s!<qn#F<>;$,
.=pack'N*',"@{[unpack'C*',$_]
}"for split/</;$_=$,,y[A-Z a-z]
         {}cd;print lc

[download]

In reply to Re^2: Exporting variables from perl script to shell by Stevie-O
in thread Exporting variables from perl script to shell by hash

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