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  1. /*
  2.  * Copyright (c) 2005 Martin Decky
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. /** @addtogroup libc
  30.  * @{
  31.  */
  32. /** @file
  33.  */
  34.  
  35. #include <string.h>
  36. #include <unistd.h>
  37. #include <ctype.h>
  38. #include <limits.h>
  39. #include <align.h>
  40.  
  41.  
  42. /* Dummy implementation of mem/ functions */
  43.  
  44. void *memset(void *s, int c, size_t n)
  45. {
  46.     char *os = s;
  47.    
  48.     while (n--)
  49.         *(os++) = c;
  50.    
  51.     return s;
  52. }
  53.  
  54. struct along {
  55.     unsigned long n;
  56. } __attribute__ ((packed));
  57.  
  58. static void *unaligned_memcpy(void *dst, const void *src, size_t n)
  59. {
  60.     int i, j;
  61.     struct along *adst = dst;
  62.     const struct along *asrc = src;
  63.  
  64.     for (i = 0; i < n / sizeof(unsigned long); i++)
  65.         adst[i].n = asrc[i].n;
  66.        
  67.     for (j = 0; j < n % sizeof(unsigned long); j++)
  68.         ((unsigned char *) (((unsigned long *) dst) + i))[j] = ((unsigned char *) (((unsigned long *) src) + i))[j];
  69.        
  70.     return (char *) src;
  71. }
  72.  
  73. void *memcpy(void *dst, const void *src, size_t n)
  74. {
  75.     int i, j;
  76.  
  77.     if (((long) dst & (sizeof(long) - 1)) || ((long) src & (sizeof(long) - 1)))
  78.         return unaligned_memcpy(dst, src, n);
  79.  
  80.     for (i = 0; i < n / sizeof(unsigned long); i++)
  81.         ((unsigned long *) dst)[i] = ((unsigned long *) src)[i];
  82.        
  83.     for (j = 0; j < n % sizeof(unsigned long); j++)
  84.         ((unsigned char *) (((unsigned long *) dst) + i))[j] = ((unsigned char *) (((unsigned long *) src) + i))[j];
  85.        
  86.     return (char *) src;
  87. }
  88.  
  89. void *memmove(void *dst, const void *src, size_t n)
  90. {
  91.     int i, j;
  92.    
  93.     if (src > dst)
  94.         return memcpy(dst, src, n);
  95.  
  96.     for (j = (n % sizeof(unsigned long)) - 1; j >= 0; j--)
  97.         ((unsigned char *) ((unsigned long *) dst))[j] = ((unsigned char *) ((unsigned long *) src))[j];
  98.  
  99.     for (i = n / sizeof(unsigned long) - 1; i >=0 ; i--)
  100.         ((unsigned long *) dst)[i] = ((unsigned long *) src)[i];
  101.        
  102.     return (char *) src;
  103. }
  104.  
  105. /** Compare two memory areas.
  106.  *
  107.  * @param s1    Pointer to the first area to compare.
  108.  * @param s2    Pointer to the second area to compare.
  109.  * @param len   Size of the first area in bytes. Both areas must have the same
  110.  *      length.
  111.  * @return  If len is 0, return zero. If the areas match, return zero.
  112.  *      Otherwise return non-zero.
  113.  */
  114. int bcmp(const char *s1, const char *s2, size_t len)
  115. {
  116.     for (; len && *s1++ == *s2++; len--)
  117.         ;
  118.     return len;
  119. }
  120.  
  121. /** Count the number of characters in the string, not including terminating 0.
  122.  * @param str string
  123.  * @return number of characters in string.
  124.  */
  125. size_t strlen(const char *str)
  126. {
  127.     size_t counter = 0;
  128.  
  129.     while (str[counter] != 0)
  130.         counter++;
  131.  
  132.     return counter;
  133. }
  134.  
  135. int strcmp(const char *a, const char *b)
  136. {
  137.     int c = 0;
  138.    
  139.     while (a[c] && b[c] && (!(a[c] - b[c])))
  140.         c++;
  141.    
  142.     return (a[c] - b[c]);
  143.    
  144. }
  145.  
  146.  
  147. /** Return pointer to the first occurence of character c in string
  148.  * @param str scanned string
  149.  * @param c searched character (taken as one byte)
  150.  * @return pointer to the matched character or NULL if it is not found in given string.
  151.  */
  152. char *strchr(const char *str, int c)
  153. {
  154.     while (*str != '\0') {
  155.         if (*str == (char) c)
  156.             return (char *) str;
  157.         str++;
  158.     }
  159.  
  160.     return NULL;
  161. }
  162.  
  163. /** Return pointer to the last occurence of character c in string
  164.  * @param str scanned string
  165.  * @param c searched character (taken as one byte)
  166.  * @return pointer to the matched character or NULL if it is not found in given string.
  167.  */
  168. char *strrchr(const char *str, int c)
  169. {
  170.     char *retval = NULL;
  171.  
  172.     while (*str != '\0') {
  173.         if (*str == (char) c)
  174.             retval = (char *) str;
  175.         str++;
  176.     }
  177.  
  178.     return (char *) retval;
  179. }
  180.  
  181. /** Convert string to a number.
  182.  * Core of strtol and strtoul functions.
  183.  * @param nptr pointer to string
  184.  * @param endptr if not NULL, function stores here pointer to the first invalid character
  185.  * @param base zero or number between 2 and 36 inclusive
  186.  * @param sgn its set to 1 if minus found
  187.  * @return result of conversion.
  188.  */
  189. static unsigned long _strtoul(const char *nptr, char **endptr, int base, char *sgn)
  190. {
  191.     unsigned char c;
  192.     unsigned long result = 0;
  193.     unsigned long a, b;
  194.     const char *str = nptr;
  195.     const char *tmpptr;
  196.    
  197.     while (isspace(*str))
  198.         str++;
  199.    
  200.     if (*str == '-') {
  201.         *sgn = 1;
  202.         ++str;
  203.     } else if (*str == '+')
  204.         ++str;
  205.    
  206.     if (base) {
  207.         if ((base == 1) || (base > 36)) {
  208.             /* FIXME: set errno to EINVAL */
  209.             return 0;
  210.         }
  211.         if ((base == 16) && (*str == '0') && ((str[1] == 'x') || (str[1] == 'X'))) {
  212.             str += 2;
  213.         }
  214.     } else {
  215.         base = 10;
  216.        
  217.         if (*str == '0') {
  218.             base = 8;
  219.             if ((str[1] == 'X') || (str[1] == 'x'))  {
  220.                 base = 16;
  221.                 str += 2;
  222.             }
  223.         }
  224.     }
  225.    
  226.     tmpptr = str;
  227.  
  228.     while (*str) {
  229.         c = *str;
  230.         c = (c >= 'a' ? c - 'a' + 10 : (c >= 'A' ? c - 'A' + 10 : (c <= '9' ? c - '0' : 0xff)));
  231.         if (c > base) {
  232.             break;
  233.         }
  234.        
  235.         a = (result & 0xff) * base + c;
  236.         b = (result >> 8) * base + (a >> 8);
  237.        
  238.         if (b > (ULONG_MAX >> 8)) {
  239.             /* overflow */
  240.             /* FIXME: errno = ERANGE*/
  241.             return ULONG_MAX;
  242.         }
  243.    
  244.         result = (b << 8) + (a & 0xff);
  245.         ++str;
  246.     }
  247.    
  248.     if (str == tmpptr) {
  249.         /* no number was found => first invalid character is the first character of the string */
  250.         /* FIXME: set errno to EINVAL */
  251.         str = nptr;
  252.         result = 0;
  253.     }
  254.    
  255.     if (endptr)
  256.         *endptr = (char *) str;
  257.  
  258.     if (nptr == str) {
  259.         /*FIXME: errno = EINVAL*/
  260.         return 0;
  261.     }
  262.  
  263.     return result;
  264. }
  265.  
  266. /** Convert initial part of string to long int according to given base.
  267.  * The number may begin with an arbitrary number of whitespaces followed by optional sign (`+' or `-').
  268.  * If the base is 0 or 16, the prefix `0x' may be inserted and the number will be taken as hexadecimal one.
  269.  * If the base is 0 and the number begin with a zero, number will be taken as octal one (as with base 8).
  270.  * Otherwise the base 0 is taken as decimal.
  271.  * @param nptr pointer to string
  272.  * @param endptr if not NULL, function stores here pointer to the first invalid character
  273.  * @param base zero or number between 2 and 36 inclusive
  274.  * @return result of conversion.
  275.  */
  276. long int strtol(const char *nptr, char **endptr, int base)
  277. {
  278.     char sgn = 0;
  279.     unsigned long number = 0;
  280.    
  281.     number = _strtoul(nptr, endptr, base, &sgn);
  282.  
  283.     if (number > LONG_MAX) {
  284.         if ((sgn) && (number == (unsigned long) (LONG_MAX) + 1)) {
  285.             /* FIXME: set 0 to errno */
  286.             return number;     
  287.         }
  288.         /* FIXME: set ERANGE to errno */
  289.         return (sgn ? LONG_MIN : LONG_MAX);
  290.     }
  291.    
  292.     return (sgn ? -number : number);
  293. }
  294.  
  295.  
  296. /** Convert initial part of string to unsigned long according to given base.
  297.  * The number may begin with an arbitrary number of whitespaces followed by optional sign (`+' or `-').
  298.  * If the base is 0 or 16, the prefix `0x' may be inserted and the number will be taken as hexadecimal one.
  299.  * If the base is 0 and the number begin with a zero, number will be taken as octal one (as with base 8).
  300.  * Otherwise the base 0 is taken as decimal.
  301.  * @param nptr pointer to string
  302.  * @param endptr if not NULL, function stores here pointer to the first invalid character
  303.  * @param base zero or number between 2 and 36 inclusive
  304.  * @return result of conversion.
  305.  */
  306. unsigned long strtoul(const char *nptr, char **endptr, int base)
  307. {
  308.     char sgn = 0;
  309.     unsigned long number = 0;
  310.    
  311.     number = _strtoul(nptr, endptr, base, &sgn);
  312.  
  313.     return (sgn ? -number : number);
  314. }
  315.  
  316. char *strcpy(char *dest, const char *src)
  317. {
  318.     char *orig = dest;
  319.    
  320.     while ((*(dest++) = *(src++)));
  321.     return orig;
  322. }
  323.  
  324. char *strncpy(char *dest, const char *src, size_t n)
  325. {
  326.     char *orig = dest;
  327.    
  328.     while ((*(dest++) = *(src++)) && --n);
  329.     return orig;
  330. }
  331.  
  332. /** @}
  333.  */
  334.