wow. that was easy: git mv core nucleus

[feisty_meow.git] / nucleus / library / basis / environment.cpp

diff --git a/nucleus/library/basis/environment.cpp b/nucleus/library/basis/environment.cpp
new file mode 100644 (file)
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+++ b/nucleus/library/basis/environment.cpp
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+//////////////
+// Name   : environment
+// Author : Chris Koeritz
+//////////////
+// Copyright (c) 1994-$now By Author.  This program is free software; you can
+// redistribute it and/or modify it under the terms of the GNU General Public
+// License as published by the Free Software Foundation:
+//     http://www.gnu.org/licenses/gpl.html
+// or under the terms of the GNU Library license:
+//     http://www.gnu.org/licenses/lgpl.html
+// at your preference.  Those licenses describe your legal rights to this
+// software, and no other rights or warranties apply.
+// Please send updates for this code to: fred@gruntose.com -- Thanks, fred.
+//////////////
+
+#include "environment.h"
+
+#include <stdlib.h>
+#include <sys/types.h>
+#ifdef __UNIX__
+  #include <unistd.h>
+  #include <sys/times.h>
+#endif
+#ifdef __WIN32__
+  #define _WINSOCKAPI_  // make windows.h happy about winsock.
+  #include <windows.h>
+  #include <mmsystem.h>
+#endif
+
+namespace basis {
+
+astring environment::get(const astring &variable_name)
+{
+#ifdef __WIN32__
+  char *value = getenv(variable_name.upper().observe());
+    // dos & os/2 require upper case for the name, so we just do it that way.
+#else
+  char *value = getenv(variable_name.observe());
+    // reasonable OSes support mixed-case environment variables.
+#endif
+  astring to_return;
+  if (value)
+    to_return = astring(value);
+  return to_return;
+}
+
+bool environment::set(const astring &variable_name, const astring &value)
+{
+  int ret = 0;
+#ifdef __WIN32__
+  astring assignment = variable_name + "=" + value;
+  ret = _putenv(assignment.s());
+#else
+  ret = setenv(variable_name.s(), value.s(), true);
+#endif
+  return !ret;
+}
+
+basis::un_int environment::system_uptime()
+{
+#ifdef __WIN32__
+  return timeGetTime();
+#else
+  static clock_t __ctps = sysconf(_SC_CLK_TCK);  // clock ticks per second.
+  static const double __multiplier = 1000.0 / double(__ctps);
+    // the multiplier gives us our full range for the tick counter.
+
+  // read uptime info from the OS.
+  tms uptime;
+  basis::un_int real_ticks = times(&uptime);
+
+  // now turn this into the number of milliseconds.
+  double ticks_up = (double)real_ticks;
+  ticks_up = ticks_up * __multiplier;  // convert to time here.
+
+  // we use the previous version of this calculation, which expected a basis::u_int
+  // to double conversion to provide a modulo operation rather than just leaving
+  // the basis::un_int at its maximum value (2^32-1).  however, that expectation is not
+  // guaranteed on some platforms (e.g., ARM processor with floating point
+  // emulation) and thus it becomes a bug around 49 days and 17 hours into
+  // OS uptime because the value gets stuck at 2^32-1 and never rolls over.
+  return basis::un_int(ticks_up);
+#endif
+}
+
+} //namespace.
+