I've never used it and I am not sure where it came from (read untested) but I found this in my code archive, it might be useful as a starting point if for some reason you can't use the YAML solution.

sub source_shell_profile {
# source a shell profile and extract ENV vars 
  my($profile) = $_[0];
  local(*STDIN,*STDERR);

  # could just close STDIN instead, but some programs
  # don't deal with that very well...
  open(STDIN,"/dev/null");   
                             
  open(STDERR,">/dev/null");
  my %env = map {chomp;split(/=/,$_,2)} `. $profile; env`;
  return %env;
}
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