my @e;  # xml elements    my $e;  # an xml element    my %a;  # element attributes    # Check for valid root node    my $name = $root->get_name();    $name eq "resolution_parameters" or die	"file $file is not a resolution parameters file\n";    # Get spectral grids    # The "res" attribute values are the keys of %spec_grid    # The values are references to a hash containing the nlon, nlat keys    @e = $xml->elements_by_name( "spectral_grid" );    %a = ();    my %spec_grid = ();    while ( $e = shift @e ) {	%a = $e->get_attributes();	$spec_grid{"$a{'res'}"} = { 'nlon' => $a{'nlon'},				    'nlat' => $a{'nlat'}				  };    }    # Get finite volume grids    # The "res" attribute values are the keys of %fv_grid    # The values are references to a hash containing the nlon, nlat keys    @e = $xml->elements_by_name( "fv_grid" );    %a = ();    my %fv_grid = ();    while ( $e = shift @e ) {	%a = $e->get_attributes();	$fv_grid{"$a{'res'}"} = { 'nlon' => $a{'nlon'},				  'nlat' => $a{'nlat'}				};    }    # Get spectral truncation parameters    # The "res" attribute values are the keys of %spec_trunc    # The values are references to a hash containing the m, n, and k keys    @e = $xml->elements_by_name( "spectral_trunc" );    %a = ();    my %spec_trunc = ();    while ( $e = shift @e ) {	%a = $e->get_attributes();	$spec_trunc{"$a{'res'}"} = { 'm' => $a{'m'},				     'n' => $a{'n'},				     'k' => $a{'k'}				   };    }    return \%spec_grid, \%fv_grid, \%spec_trunc;}#-------------------------------------------------------------------------------sub get_sys_defaults{    my ($file, $os) = @_;    my $xml = XML::Lite->new( $file );    my $root = $xml->root_element();    my $e;          # xml element    my %a;          # element attributes    my %sys = ();   # return values    # Check for valid root node    my $name = $root->get_name();    $name eq "system_defaults" or die	"file $file is not a system defaults file\n";    # SPMD    $e = $xml->elements_by_name( "spmd" );    %a = $e->get_attributes();    $sys{'spmd'} = $a{$os};    # Threads    $e = $xml->elements_by_name( "threads" );    %a = $e->get_attributes();    $sys{'omp'} = $a{$os};    return %sys;}#-------------------------------------------------------------------------------sub absolute_path {## Convert a pathname into an absolute pathname, expanding any . or .. characters.# Assumes pathnames refer to a local filesystem.# Assumes the directory separator is "/".#  my $path = shift;  my $cwd = getcwd();  # current working directory  my $abspath;         # resulting absolute pathname# Strip off any leading or trailing whitespace.  (This pattern won't match if# there's embedded whitespace.  $path =~ s!^\s*(\S*)\s*$!$1!;# Convert relative to absolute path.  if ($path =~ m!^\.$!) {          # path is "."      return $cwd;  } elsif ($path =~ m!^\./!) {     # path starts with "./"      $path =~ s!^\.!$cwd!;  } elsif ($path =~ m!^\.\.$!) {   # path is ".."      $path = "$cwd/..";  } elsif ($path =~ m!^\.\./!) {   # path starts with "../"      $path = "$cwd/$path";  } elsif ($path =~ m!^[^/]!) {    # path starts with non-slash character      $path = "$cwd/$path";  }  my ($dir, @dirs2);  my @dirs = split "/", $path, -1;   # The -1 prevents split from stripping trailing nulls                                     # This enables correct processing of the input "/".  # Remove any "" that are not leading.  for (my $i=0; $i<=$#dirs; ++$i) {      if ($i == 0 or $dirs[$i] ne "") {	  push @dirs2, $dirs[$i];      }  }  @dirs = ();  # Remove any "."  foreach $dir (@dirs2) {      unless ($dir eq ".") {	  push @dirs, $dir;      }  }  @dirs2 = ();  # Remove the "subdir/.." parts.  foreach $dir (@dirs) {    if ( $dir !~ /^\.\.$/ ) {        push @dirs2, $dir;    } else {        pop @dirs2;   # remove previous dir when current dir is ..    }  }  if ($#dirs2 == 0 and $dirs2[0] eq "") { return "/"; }  $abspath = join '/', @dirs2;  return( $abspath );}#-------------------------------------------------------------------------------sub subst_env_path {## Substitute for any environment variables contained in a pathname.# Assumes the directory separator is "/".#  my $path = shift;  my $newpath;         # resulting pathname# Strip off any leading or trailing whitespace.  (This pattern won't match if# there's embedded whitespace.  $path =~ s!^\s*(\S*)\s*$!$1!;  my ($dir, @dirs2);  my @dirs = split "/", $path, -1;   # The -1 prevents split from stripping trailing nulls                                     # This enables correct processing of the input "/".  foreach $dir (@dirs) {    if ( $dir =~ /^\$(.+)$/ ) {        push @dirs2, $ENV{$1};    } else {        push @dirs2, $dir;    }  }  $newpath = join '/', @dirs2;  return( $newpath );}#-------------------------------------------------------------------------------sub mkdirp {    my ($dir) = @_;    my (@dirs) = split /\//, $dir;    my (@subdirs, $path);    # if $dir is absolute pathname then @dirs will start with ""    if ($dirs[0] eq "") { push @subdirs, shift @dirs; }      while ( @dirs ) { # check that each subdir exists and mkdir if it doesn't	push @subdirs, shift @dirs;	$path = join '/', @subdirs;	unless (-d $path or mkdir($path, 0777)) { return 0; }    }    return 1;}#-------------------------------------------------------------------------------sub get_option {    my ($mes, @expect) = @_;    my ($ans, $expect, $max_tries);    $max_tries = 5;    print $mes;    while ($max_tries) {	$ans = <>; chomp $ans;	--$max_tries;	$ans =~ s/^\s+//;	$ans =~ s/\s+$//;	# Check for null response which indicates that default is accepted.	unless ($ans) { return ""; }	foreach $expect (@expect) {	    if ($ans =~ /^$expect$/i) { return $expect; }	}	if ($max_tries > 1) {	    print "$ans does not match any of the expected values: @expect\n";	    print "Please try again: ";	} elsif ($max_tries == 1) {	    print "$ans does not match any of the expected values: @expect\n";	    print "Last chance! ";	}    }    die "Failed to get answer to question: $mes\n";}#-------------------------------------------------------------------------------sub valid_option {    my ($val, @expect) = @_;    my ($expect);    $val =~ s/^\s+//;    $val =~ s/\s+$//;    foreach $expect (@expect) {	if ($val =~ /^$expect$/i) { return $expect; }    }    return undef;}#-------------------------------------------------------------------------------sub validate_options {    my ($source, $opts) = @_;    my ($opt, $old, @expect);        # dyn    $opt = 'dyn';    @expect = ('eul', 'sld', 'fv');    if (defined $opts->{$opt}) {	$old = $opts->{$opt};	$opts->{$opt} = valid_option($old, @expect)	    or die "** invalid value of $opt ($old) specified in $source\n".                   "** expected one of: @expect\n";    }    # phys    $opt = 'phys';    @expect = ('cam1', 'ccm366');    if (defined $opts->{$opt}) {	$old = $opts->{$opt};	$opts->{$opt} = valid_option($old, @expect)	    or die "** invalid value of $opt ($old) specified in $source\n".                   "** expected one of: @expect\n";    }    # ocn    $opt = 'ocn';    @expect = ('dom', 'som');    if (defined $opts->{$opt}) {	$old = $opts->{$opt};	$opts->{$opt} = valid_option($old, @expect)	    or die "** invalid value of $opt ($old) specified in $source\n".                   "** expected one of: @expect\n";    }    # resolution    unless ($opts->{'res'} eq 'custom') {	if ( defined($opts->{'nlon'}) or defined($opts->{'nlat'}) ) {	    die "** must set -res option to 'custom' for the -nlon or -nlat options\n".		"** to be recognized\n";	}    }    unless ($opts->{'res'} eq 'custom' and $opts->{'dyn'} ne 'fv') {	if ( defined($opts->{'trk'}) or defined($opts->{'trm'}) or defined($opts->{'trn'}) ) {	    die "** must set -res option to 'custom' and -dyn to either 'eul' or 'sld'\n".		"** for the -trk, -trm, or -trn options to be recognized\n";	}    }}#-------------------------------------------------------------------------------sub get_gmake {# check for a valid version of GNU make in the user's path    my @makenames = @_;    my ($make, $retval);    foreach $make (@makenames) {	$retval = `$make -v 2>&1`;	return $make if ($retval =~ /GNU Make/);    }    return;}#-------------------------------------------------------------------------------sub check_fc {# Create a "hello world" test code in Fortran 90 syntax to check the compiler.# If successful then the name of the compiler used is returned.    my ($gmake, $cfgdir) = @_;    my $fh = new IO::File;    my $file = 'test_fc.F90';    $fh->open(">$file") or die "** can't open file: $file\n";    print $fh  <<"EOF";module m1   private   public :: hellocontainssubroutine hello()   implicit none   print *, 'hello world'end subroutine helloend module m1program main   use m1, only: hello   implicit none   call helloend program mainEOF    $fh->close;    # execute the test_fc target in the CAM Makefile    my $cmd = "$gmake test_fc 2>&1";    my $out = `$cmd`;    if ($CHILD_ERROR) { 	die <<"EOF";**** FAILED ****Issued the command:$cmdThe output was:$outEOF    }    # clean-up (Srcfiles and Depends are created by the makefile)    unlink 'test_fc.F90', 'test_fc.o', 'test_fc', glob("[Mm]1.[Mm][Oo][Dd]"), 'Srcfiles', 'Depends';    # search make output for name of Fortran compiler    $out =~ /(\w*f9\w+)/;    return $1;}#-------------------------------------------------------------------------------sub check_netcdf {# Create a test code that has an external reference to the netCDF library# and check that the Makefile can build it.  Returns 0 on success.    my ($gmake, $cfgdir) = @_;    my $fh = new IO::File;    my $file = 'test_nc.F90';    $fh->open(">$file") or die "** can't open file: $file\n";    print $fh  <<"EOF";program main   implicit none#include <netcdf.inc>   integer :: cmode, ncid, ret   ret = nf_create('foo.nc', cmode, ncid)end program mainEOF    $fh->close;    # execute the test_nc target in the CAM Makefile    my $cmd = "$gmake test_nc 2>&1";    my $out = `$cmd`;    if ($CHILD_ERROR) { 	die <<"EOF";**** FAILED ****Issued the command:$cmdThe output was:$outEOF    }    # clean-up (Srcfiles and Depends are created by the makefile)    unlink 'test_nc.F90', 'test_nc.o', 'test_nc', 'Srcfiles', 'Depends';    return 0;}#-------------------------------------------------------------------------------sub check_mpi {# Create a test code that has an external reference to the MPI library# and check that the Makefile can build it.  Returns 0 on