File content as of revision 18:11b9d98ecae2:

/*****************************************************************************
*
*  strlib.c - String Library functions implementation
*  Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
*
*  Redistribution and use in source and binary forms, with or without
*  modification, are permitted provided that the following conditions
*  are met:
*
*    Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
*
*    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.
*
*    Neither the name of Texas Instruments Incorporated 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.
*
*****************************************************************************/

/*#include <stdlib.h>
#include <stdio.h>
#include <string.h>*/
#include "mbed.h"
#include "strlib.h"

//*****************************************************************************
//
//! \brief   Integer to ASCII
//!
//! \param  n is the number to be converted to ASCII
//! \param s is a pointer to an array where the ASCII string will be placed
//! \param b is the base (10 for decimal)
//!
//! \return none
//
//*****************************************************************************
char *itoa(int n, char *s, int b)
{
    const char digits[] = "0123456789abcdefghijklmnopqrstuvwxyz";
    unsigned int i = 0;
    int sign;
    
    if ((sign = n) < 0)
        n = -n;

    do {
        s[i++] = digits[n % b];
    } while ((n /= b) > 0);

    if (sign < 0)
        s[i++] = '-';
    s[i] = '\0';

    return strrev(s);
}

//*****************************************************************************
//
//! \brief   Reverses a string
//!
//! \param  str is a pointer to the string to be reversed
//!
//! \return none
//
//*****************************************************************************
char *strrev(char *str)
{
    char *p1, *p2;

    if (!str || !*str)
        return str;

    for (p1 = str, p2 = str + strlen(str) - 1; p2 > p1; ++p1, --p2) {
        *p1 ^= *p2;
        *p2 ^= *p1;
        *p1 ^= *p2;
    }

    return str;
}

//*****************************************************************************
//
//! atoc
//!
//! \param  none
//!
//! \return none
//!
//! \brief  Convert nibble to hexdecimal from ASCII
//
//*****************************************************************************
unsigned char
atoc(char data)
{
    unsigned char ucRes = 0;

    if ((data >= 0x30) && (data <= 0x39))
    {
        ucRes = data - 0x30;
    }
    else
    {
        if (data == 'a')
        {
            ucRes = 0x0a;;
        }
        else if (data == 'b')
        {
            ucRes = 0x0b;
        }
        else if (data == 'c')
        {
            ucRes = 0x0c;
        }
        else if (data == 'd')
        {
            ucRes = 0x0d;
        }
        else if (data == 'e')
        {
            ucRes = 0x0e;
        }
        else if (data == 'f')
        {
            ucRes = 0x0f;
        }
    }


    return ucRes;
}


//*****************************************************************************
//
//! atoshort
//!
//! \param  none
//!
//! \return none
//!
//! \brief  Convert 2 nibbles in ASCII into a short number
//
//*****************************************************************************

unsigned short
atoshort(char b1, char b2)
{
    unsigned short usRes;

    usRes = (atoc(b1)) * 16 | atoc(b2);

    return usRes;
}

//*****************************************************************************
//
//! ascii_to_char
//!
//! \param  none
//!
//! \return none
//!
//! \brief  Convert 2 bytes in ASCII into one character
//
//*****************************************************************************

unsigned char
ascii_to_char(char b1, char b2)
{
    unsigned char ucRes;

    ucRes = (atoc(b1)) << 4 | (atoc(b2));

    return ucRes;
}