px4-firmware/nuttx/tools/b16.c

122 lines
4.0 KiB
C

/****************************************************************************
* 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;
}