armsrc/string.c

   1 //-----------------------------------------------------------------------------
   2 // Jonathan Westhues, Sept 2005
   3 //
   4 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
   5 // at your option, any later version. See the LICENSE.txt file for the text of
   6 // the license.
   7 //-----------------------------------------------------------------------------
   8 // Common string.h functions
   9 //-----------------------------------------------------------------------------
  10
  11 #include "string.h"
  12 #include <stdint.h>
  13
  14 void *memcpy(void *dest, const void *src, int len)
  15 {
  16         uint8_t *d = dest;
  17         const uint8_t *s = src;
  18         while((len--) > 0) {
  19                 *d = *s;
  20                 d++;
  21                 s++;
  22         }
  23         return dest;
  24 }
  25
  26 void *memset(void *dest, int c, int len)
  27 {
  28         uint8_t *d = dest;
  29         while((len--) > 0) {
  30                 *d = c;
  31                 d++;
  32         }
  33         return dest;
  34 }
  35
  36 int memcmp(const void *av, const void *bv, int len)
  37 {
  38         const uint8_t *a = av;
  39         const uint8_t *b = bv;
  40
  41         while((len--) > 0) {
  42                 if(*a != *b) {
  43                         return *a - *b;
  44                 }
  45                 a++;
  46                 b++;
  47         }
  48         return 0;
  49 }
  50
  51 void memxor(uint8_t * dest, uint8_t * src, size_t len) {
  52    for( ; len > 0; len--,dest++,src++)
  53        *dest ^= *src;
  54 }
  55
  56 int strlen(const char *str)
  57 {
  58         int l = 0;
  59         while(*str) {
  60                 l++;
  61                 str++;
  62         }
  63         return l;
  64 }
  65
  66 char* strncat(char *dest, const char *src, unsigned int n)
  67 {
  68         unsigned int dest_len = strlen(dest);
  69         unsigned int i;
  70
  71         for (i = 0 ; i < n && src[i] != '\0' ; i++)
  72                 dest[dest_len + i] = src[i];
  73         dest[dest_len + i] = '\0';
  74
  75         return dest;
  76 }
  77
  78 char* strcat(char *dest, const char *src)
  79 {
  80         unsigned int dest_len = strlen(dest);
  81         unsigned int i;
  82
  83         for (i = 0 ; src[i] != '\0' ; i++)
  84                 dest[dest_len + i] = src[i];
  85         dest[dest_len + i] = '\0';
  86
  87         return dest;
  88 }
  89 ////////////////////////////////////////// code to do 'itoa'
  90
  91 /* reverse:  reverse string s in place */
  92 void strreverse(char s[])
  93 {
  94     int c, i, j;
  95
  96     for (i = 0, j = strlen(s)-1; i<j; i++, j--) {
  97         c = s[i];
  98         s[i] = s[j];
  99         s[j] = c;
 100     }
 101 }
 102
 103 /* itoa:  convert n to characters in s */
 104 void itoa(int n, char s[])
 105 {
 106     int i, sign;
 107
 108     if ((sign = n) < 0)  /* record sign */
 109         n = -n;          /* make n positive */
 110     i = 0;
 111     do {       /* generate digits in reverse order */
 112         s[i++] = n % 10 + '0';   /* get next digit */
 113     } while ((n /= 10) > 0);     /* delete it */
 114     if (sign < 0)
 115         s[i++] = '-';
 116     s[i] = '\0';
 117     strreverse(s);
 118 }
 119
 120 //////////////////////////////////////// END 'itoa' CODE