As part of a program I'm writing, I need to read some variables from a bash script and do some bash-style interpolation. My current code:

sub get_depend {
  my $ebuildfname = shift;
  my $ebuildcontents;
  my %ebuildvars;
  my $pkgname = $ebuildfname;

  $pkgname =~ s|/usr/portage/||;
  $pkgname =~ s|(.+)/.+/(.+).ebuild|$1/$2|;
  my $pkg = parse_package_name($pkgname);
  $pkg->{version} =~ s/^-//;
  $ebuildvars{PV} = "$pkg->{version}";

  open EBUILD, "< $ebuildfname" or die "Couldn't open '$ebuildfname'\n
+";
  while(<EBUILD>) {
    $ebuildcontents .= $_;
  }
  close EBUILD;

  while($ebuildcontents =~ /\b([-A-Z0-9_]+)=\"(.*?)\"{1}?/sgc) {
    $ebuildvars{$1} = $2;
  }
  foreach(keys %ebuildvars) {
    $ebuildvars{$_} =~ s/\$\{?([-A-Z0-9_]+)\}?/$ebuildvars{$1}/gs;
  }

  my $depend = $ebuildvars{'DEPEND'} || '';
  $depend =~ s/(\s+|\n+)/ /gs;

  return $depend;
}

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This one-pass interpolation works somewhat, but it doesn't get all the variables (for example: VAR1="something $VAR2" VAR2="test $VAR3" VAR3="anything $VAR4" would give me VAR1="something test $VAR3" VAR2="test $VAR3" VAR3="anything $VAR4"). How can I make this work? If I need to, I can pass it through bash. I just don't know how (with the ability to get the values back).

In reply to simulating bash by agaffney

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