1 files changed, 53 insertions, 0 deletions
diff --git a/fitsy++/mmapincr.C b/fitsy++/mmapincr.C
new file mode 100644
index 0000000..b0118d3
--- /dev/null
+++ b/fitsy++/mmapincr.C
@@ -0,0 +1,53 @@
+// Copyright (C) 1999-2018
+// Smithsonian Astrophysical Observatory, Cambridge, MA, USA
+// For conditions of distribution and use, see copyright notice in "copyright"
+
+#include "mmapincr.h"
+
+#ifndef __WIN32
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+
+FitsMMapIncr::FitsMMapIncr(const char* fn)
+{
+  // parse the fn and options
+  parse(fn);
+  if (!valid_)
+    return;
+
+  // reset
+  valid_ =0;
+
+  if (!pName_)
+    return;
+
+  // Map the file.
+  int fd = open(pName_, O_RDONLY);
+  if (fd == -1)
+    return;
+
+  struct stat info;
+  if (fstat(fd, &info) < 0)
+    return;
+
+  close(fd);
+
+  // check to see if we have something, we may have a small array
+  if (info.st_size <= 0)
+    return;
+
+  filesize_ = info.st_size;
+
+  // so far, so good
+  valid_ = 1;
+}
+
+#else
+
+FitsMMapIncr::FitsMMapIncr(const char* fn) {}
+
+#endif