support linux system

cores/arduino/dtostrf.c

@@ -0,0 +1,37 @@
+/*
+  dtostrf - Emulation for dtostrf function from avr-libc
+  Copyright (c) 2013 Arduino.  All rights reserved.
+  Written by Cristian Maglie <c.maglie@bug.st>
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#include "dtostrf.h"
+
+char *dtostrf(double val, signed char width, unsigned char prec, char *sout)
+{
+    char fmt[20];
+    snprintf(fmt, sizeof(fmt), "%%%d.%df", width, prec);
+    sprintf(sout, fmt, val);
+    return sout;
+}
+
+char *dtostrnf(double val, signed char width, unsigned char prec, char *sout, size_t sout_size)
+{
+    char fmt[20];
+    snprintf(fmt, sizeof(fmt), "%%%d.%df", width, prec);
+    snprintf(sout, sout_size, fmt, val);
+    return sout;
+}