text: /****************************************************************************
   * tools/b16.c
   *
   *   Copyright (C) 2007-2012 Gregory Nutt. All rights reserved.
   *   Author: Gregory Nutt <gnutt@nuttx.org>
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   * 3. Neither the name NuttX nor the names of its contributors may be
   *    used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
   * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
   * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   *
   ****************************************************************************/
  
  /****************************************************************************
   * Included Files
   ****************************************************************************/
  
  #include <stdio.h>
  #include <stdlib.h>
  
  /****************************************************************************
   * Private Functions
   ****************************************************************************/
  
  static void show_usage(const char *progname)
  {
    fprintf(stderr, "\nUSAGE: %s <b16_t>|<float>\n", progname);
    fprintf(stderr, "\nWhere:\n");
    fprintf(stderr, "  <b16_t>:\n");
    fprintf(stderr, "    A b16 fixed precision value in hexadecimal form: E.g., 0x00010000\n");
    fprintf(stderr, "    Any value begininning with '0' will assumed by be hexadecimal format\n");
    fprintf(stderr, "  <float>:\n");
    fprintf(stderr, "    A floating value in standard form: E.g., 5.1\n");
    exit(EXIT_FAILURE);
  }
  
  /****************************************************************************
   * Public Functions
   ****************************************************************************/
  
  int main(int argc, char **argv, char **envp)
  {
    double fvalue;
    unsigned long ulvalue;
    long lvalue;
    const char *str;
    char *endptr;
  
    /* There must be exactly one argument */
  
    if (argc != 2)
      {
        fprintf(stderr, "\nExpected a single argument\n");
        show_usage(argv[0]);
      }
    str = argv[1];
  
    /* If the value begins with a zero, we will assume that it is a hexadecimal
     * representation.
     */
  
    if (str[0] == '0')
      {
        endptr = NULL;
        ulvalue = strtoul(str, &endptr, 16);
        if (!endptr || *endptr != '\0')
          {
            fprintf(stderr, "\nHexadecimal argument not fully converted\n");
            show_usage(argv[0]);
          }
  
        if (ulvalue >= 0x80000000)
          {
            lvalue = ~ulvalue + 1;
          }
        else
          {
            lvalue = ulvalue;
          }
  
        fvalue = ((double)lvalue) / 65536.0;
        printf("0x%08lx -> %10.5f\n", ulvalue, fvalue);
      }
    else
      {
        endptr = NULL;
        fvalue = strtod(str, &endptr);
        if (!endptr || *endptr != '\0')
          {
            fprintf(stderr, "\nFloating point argument not fully converted\n");
            show_usage(argv[0]);
          }
  
        lvalue = 65536.0 * fvalue;
        printf("%10.5f -> 0x%08lx\n", fvalue, lvalue);
      }
     
    return 0;
  }
  