project/commands.c

   1 /**************************************************************************/
   2 /*!
   3     @file     commands.c
   4     @author   K. Townsend (microBuilder.eu)
   5
   6     @brief    Common helper-functions for all commands in the 'core/cmd'
   7               command-line interpretter.
   8
   9     @section LICENSE
  10
  11     Software License Agreement (BSD License)
  12
  13     Copyright (c) 2010, microBuilder SARL
  14     All rights reserved.
  15
  16     Redistribution and use in source and binary forms, with or without
  17     modification, are permitted provided that the following conditions are met:
  18     1. Redistributions of source code must retain the above copyright
  19     notice, this list of conditions and the following disclaimer.
  20     2. Redistributions in binary form must reproduce the above copyright
  21     notice, this list of conditions and the following disclaimer in the
  22     documentation and/or other materials provided with the distribution.
  23     3. Neither the name of the copyright holders nor the
  24     names of its contributors may be used to endorse or promote products
  25     derived from this software without specific prior written permission.
  26
  27     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY
  28     EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  29     WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  30     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
  31     DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  32     (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  33     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  34     ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  35     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  36     SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  37 */
  38 /**************************************************************************/
  39
  40 #include <stdio.h>
  41 #include <string.h>   // memset
  42 #include <ctype.h>    // isdigit, isspace, etc.
  43
  44 #include "core/cmd/cmd.h"
  45 #include "commands.h"
  46
  47 /**************************************************************************/
  48 /*!
  49     @brief  Attempts to convert the supplied decimal or hexadecimal
  50           string to the matching 32-bit value.  All hexadecimal values
  51           must be preceded by either '0x' or '0X' to be properly parsed.
  52
  53     @param[in]  s
  54                 Input string
  55     @param[out] result
  56                 Signed 32-bit integer to hold the conversion results
  57
  58     @section Example
  59
  60     @code
  61     char *hex = "0xABCD";
  62     char *dec = "1234";
  63
  64     // Convert supplied values to integers
  65     int32_t hexValue, decValue;
  66     getNumber (hex, &hexValue);
  67     getNumber (dec, &decValue);
  68
  69     @endcode
  70 */
  71 /**************************************************************************/
  72 int getNumber (char *s, int32_t *result)
  73 {
  74   int32_t value;
  75   uint32_t mustBeHex = FALSE;
  76   uint32_t sgn = 1;
  77   const unsigned char hexToDec [] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 255, 255, 255, 255, 255, 255, 255, 10, 11, 12, 13, 14, 15};
  78
  79   if (!s)
  80     return 0;
  81
  82   // Check if this is a hexadecimal value
  83   if ((strlen (s) > 2) && (!strncmp (s, "0x", 2) || !strncmp (s, "0X", 2)))
  84   {
  85     mustBeHex = TRUE;
  86     s += 2;
  87   }
  88
  89   // Check for negative sign
  90   if (!mustBeHex && *s && (*s == '-'))
  91   {
  92     sgn = -1;
  93     s++;
  94   }
  95
  96   // Try to convert value
  97   for (value = 0; *s; s++)
  98   {
  99     if (mustBeHex && isxdigit ((uint8_t)*s))
 100       value = (value << 4) | hexToDec [toupper((uint8_t)*s) - '0'];
 101     else if (isdigit ((uint8_t)*s))
 102       value = (value * 10) + ((uint8_t)*s - '0');
 103     else
 104     {
 105       printf ("Malformed number. Must be decimal number, or hex value preceeded by '0x'%s", CFG_PRINTF_NEWLINE);
 106       return 0;
 107     }
 108   }
 109
 110   // Set number to negative value if required
 111   if (!mustBeHex)
 112     value *= sgn;
 113
 114   *result = value;
 115
 116   return 1;
 117 }
 118
 119
 120