small refactoring

[proxmark3-svn] / armsrc / string.c

//-----------------------------------------------------------------------------
// Jonathan Westhues, Sept 2005
//
// This code is licensed to you under the terms of the GNU GPL, version 2 or,
// at your option, any later version. See the LICENSE.txt file for the text of
// the license.
//-----------------------------------------------------------------------------
// Common string.h functions
//-----------------------------------------------------------------------------

#include "string.h"
#include <stdint.h>

void *memcpy(void *dest, const void *src, int len)
{
        uint8_t *d = dest;
        const uint8_t *s = src;
        while((len--) > 0) {
                *d = *s;
                d++;
                s++;
        }
        return dest;
}

void *memset(void *dest, int c, int len)
{
        uint8_t *d = dest;
        while((len--) > 0) {
                *d = c;
                d++;
        }
        return dest;
}

int memcmp(const void *av, const void *bv, int len)
{
        const uint8_t *a = av;
        const uint8_t *b = bv;

        while((len--) > 0) {
                if(*a != *b) {
                        return *a - *b;
                }
                a++;
                b++;
        }
        return 0;
}

void memxor(uint8_t * dest, uint8_t * src, size_t len) {
   for( ; len > 0; len--,dest++,src++)
       *dest ^= *src;
}

int strlen(const char *str)
{
        int l = 0;
        while(*str) {
                l++;
                str++;
        }
        return l;
}

char* strncat(char *dest, const char *src, unsigned int n)
{
        unsigned int dest_len = strlen(dest);
        unsigned int i;

        for (i = 0 ; i < n && src[i] != '\0' ; i++)
                dest[dest_len + i] = src[i];
        dest[dest_len + i] = '\0';

        return dest;
}

char* strcat(char *dest, const char *src)
{
        unsigned int dest_len = strlen(dest);
        unsigned int i;

        for (i = 0 ; src[i] != '\0' ; i++)
                dest[dest_len + i] = src[i];
        dest[dest_len + i] = '\0';

        return dest;
}
////////////////////////////////////////// code to do 'itoa'

/* reverse:  reverse string s in place */
void strreverse(char s[])
{
    int c, i, j;

    for (i = 0, j = strlen(s)-1; i<j; i++, j--) {
        c = s[i];
        s[i] = s[j];
        s[j] = c;
    }
}

/* itoa:  convert n to characters in s */
void itoa(int n, char s[])
{
    int i, sign;

    if ((sign = n) < 0)  /* record sign */
        n = -n;          /* make n positive */
    i = 0;
    do {       /* generate digits in reverse order */
        s[i++] = n % 10 + '0';   /* get next digit */
    } while ((n /= 10) > 0);     /* delete it */
    if (sign < 0)
        s[i++] = '-';
    s[i] = '\0';
    strreverse(s);
}

//////////////////////////////////////// END 'itoa' CODE