Doesn't really have anything to do with perl, but with the process model most operating systems, if not all, use. That is, a child cannot affect its parent, only vice versa.

What I've done is create a "mkAlias" perl script which sets up my environment by printing shell commands to STDOUT. I then evaluate it in shell as:

  eval `mkAliases`
[download]

Note that the shell pretty much removes all carriage-returns in the output (not quite true, but close enough), so separate each command from perl with a semicolon:

print qq[export VAR1="text";\n];
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Hopefully you're using a shell that can do this - if you're using CMD.EXE on Windows, sorry, but the only solution is to have perl run CMD.EXE for you.