use strict;
use warnings;
use PDL;
use PDL::IO::FlexRaw;
 
# Places in the file with known values.
my @specials = (1314724, 1388624, 7737986, 7813911);
my @nexts_expected = (1354770, 6315154, 6315155, 1354771);
 
sub testMap {
   my $pdl = shift;
   for (my $i = 0; $i < @specials; $i++) {
      my $nxt = $pdl->at($specials[$i]);
      if ($nxt != $nexts_expected[$i]) {
         print "Unexpectedly got $nxt at $i instead of ",$nexts_expected[$i],"\n";
      } else {
         print "As expected $nxt at $i is ",$nexts_expected[$i],"\n";
      }
   }
} # if
 
# Example xxx.hdr:
# Long
# 1
# 9129591
my $pdl1 =  mapflex("xxx");
print "Test values before second mapflex:\n";
testMap($pdl1);
my $pdl2 =  mapflex("yyy");
print "Test values after second mapflex:\n";
testMap($pdl1);
print "Did the contents of the second mmap overwrite?\n";
testMap($pdl2);

__END__
Output:

Test values before second mapflex:
As expected 1354770 at 0 is 1354770
As expected 6315154 at 1 is 6315154
As expected 6315155 at 2 is 6315155
As expected 1354771 at 3 is 1354771
Test values after second mapflex:
Unexpectedly got 5735779 at 0 instead of 1354770
Unexpectedly got 5340568 at 1 instead of 6315154
Unexpectedly got 4725878 at 2 instead of 6315155
Unexpectedly got 3013470 at 3 instead of 1354771
Did the contents of the second mmap overwrite?
Unexpectedly got 5735779 at 0 instead of 1354770
Unexpectedly got 5340568 at 1 instead of 6315154
Unexpectedly got 4725878 at 2 instead of 6315155
Unexpectedly got 3013470 at 3 instead of 1354771
Warning: special data without datasv is not freed currently!!.
Warning: special data without datasv is not freed currently!!.

##</code><code>##

  fd = open(argv[1], O_RDONLY);
  if (fd < 0) {
    perror(argv[1]);
    exit(1);
  }

  mapstart = (long *)mmap((void *)0, len, PROT_READ, MAP_PRIVATE, fd,
                          offset & ~MAP_MASK);
  if ((long)mapstart < 0) {
     perror("mapstart failed");
     exit(1);
  }
  close(fd);
  
  printf("Test values before second mmap:\n");
  testMap(mapstart);

  fd2 = open(argv[2], O_RDONLY);
  if (fd < 0) {
    perror(argv[2]);
    exit(1);
  }

  mapstart2 = (long *)mmap((void *)0, len, PROT_READ, MAP_PRIVATE, fd2,
                          offset & ~MAP_MASK);
  if ((long)mapstart2 < 0) {
     perror("mapstart2 failed");
     exit(1);
  }
  close(fd2);

  printf("Test values before second mmap:\n");
  testMap(mapstart);

  printf("Did the contents of the second mmap overwrite?\n");
  testMap(mapstart2);