proxmark3/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"

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) {
    const char *p;
    for (p = str; *p != '\0'; ++p) {
    }
    return p-str;
}

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