nuttx-apps/graphics/traveler/tools/libwld/wld_readdecimal.c
2016-11-11 07:04:01 -06:00

96 lines
3.1 KiB
C

/****************************************************************************
* apps/graphics/traveler/tools/libwld/wld_readdecimal.c
*
* Copyright (C) 2016 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 <stdbool.h>
#include <stdio.h>
#include "wld_utils.h"
/*************************************************************************
* Public Functions
*************************************************************************/
/*************************************************************************
* Name: wld_read_decimal
* Description:
* Read a decimal number from the steam fp
************************************************************************/
int16_t wld_read_decimal(FILE * fp)
{
int16_t value = 0;
bool negative = false;
int ch;
/* Skip over any leading spaces, new lines, or carriage returns (for MSDOS
* compatibility)
*/
do
{
ch = getc(fp);
}
while ((ch == ' ') || (ch == '\n') || (ch == '\r'));
/* if the first character is '-', then its a negative number */
if (ch == '-')
{
negative = true;
ch = getc(fp);
}
/* Now get the unsigned portion of the number */
while ((ch >= '0') && (ch <= '9'))
{
value = 10 * value + (ch - (int)'0');
ch = getc(fp);
}
/* Apply the negation, if appropriate */
if (negative)
{
value = -value;
}
return value;
}