- #include <stddef.h>
- char * ___strtok = NULL;
- char * strcpy(char * dest,const char *src)
- {
- char *tmp = dest;
- while ((*dest++ = *src++) != '\0')
- ;
- return tmp;
- }
-
- char * strncpy(char * dest,const char *src,size_t count)
- {
- char *tmp = dest;
- while (count-- && (*dest++ = *src++) != '\0')
- ;
- return tmp;
- }
-
- char * strcat(char * dest, const char * src)
- {
- char *tmp = dest;
- while (*dest)
- dest++;
- while ((*dest++ = *src++) != '\0')
- ;
- return tmp;
- }
-
- char * strncat(char *dest, const char *src, size_t count)
- {
- char *tmp = dest;
- if (count) {
- while (*dest)
- dest++;
- while ((*dest++ = *src++)) {
- if (--count == 0)
- break;
- }
- }
- return tmp;
- }
-
- int strcmp(const char * cs,const char * ct)
- {
- register signed char __res;
- while (1) {
- if ((__res = *cs - *ct++) != 0 || !*cs++)
-
- break;
- }
- return __res;
- }
-
- int strncmp(const char * cs,const char * ct,size_t count)
- {
- register signed char __res = 0;
- while (count) {
- if ((__res = *cs - *ct++) != 0 || !*cs++)
- break;
- count--;
- }
- return __res;
- }
-
- char * strchr(const char * s,char c)
- {
- for(; *s != c; ++s)
- if (*s == '\0')
- return NULL;
- return (char *) s;
- }
-
- size_t strlen(const char * s)
- {
- const char *sc;
- for (sc = s; *sc != '\0'; ++sc)
- ;
- return sc - s;
- }
-
- size_t strnlen(const char * s, size_t count)
- {
- const char *sc;
-
- for (sc = s; *sc != '\0' && count--; ++sc)
- ;
- return sc - s;
- }
-
- size_t strspn(const char *s, const char *accept)
- {
- const char *p;
- const char *a;
- size_t count = 0;
-
- for (p = s; *p != '\0'; ++p) {
- for (a = accept; *a != '\0'; ++a) {
- if (*p == *a)
- break;
- }
- if (*a == '\0')
- return count;
- ++count;
- }
-
- return count;
- }
-
- char * strpbrk(const char * cs,const char * ct)
- {
- const char *sc1,*sc2;
-
- for( sc1 = cs; *sc1 != '\0'; ++sc1) {
- for( sc2 = ct; *sc2 != '\0'; ++sc2) {
- if (*sc1 == *sc2)
- return (char *) sc1;
- }
- }
- return NULL;
- }
-
- char * strtok(char * s,const char * ct)
- {
- char *sbegin, *send;
- sbegin = s ? s : ___strtok;
- if (!sbegin) {
- return NULL;
- }
- sbegin += strspn(sbegin,ct);
- if (*sbegin == '\0') {
- ___strtok = NULL;
- return( NULL );
- }
- send = strpbrk( sbegin, ct);
- if (send && *send != '\0')
- *send++ = '\0';
- ___strtok = send;
- return (sbegin);
- }
-
- void * memset(void * s,char c,size_t count)
- {
- char *xs = (char *) s;
- while (count--)
- *xs++ = c;
- return s;
- }
-
- char * bcopy(const char * src, char * dest, int count)
- {
- char *tmp = dest;
- while (count--)
- *tmp++ = *src++;
- return dest;
- }
-
- void * memcpy(void * dest,const void *src,size_t count)
- {
- char *tmp = (char *) dest, *s = (char *) src;
- while (count--)
- *tmp++ = *s++;
- return dest;
- }
-
- void * memmove(void * dest,const void *src,size_t count)
- {
- char *tmp, *s;
- if (dest <= src) {
- tmp = (char *) dest;
- s = (char *) src;
- while (count--)
- *tmp++ = *s++;
- }
- else {
- tmp = (char *) dest + count;
- s = (char *) src + count;
- while (count--)
- *--tmp = *--s;
- }
- return dest;
- }
-
- int memcmp(const void * cs,const void * ct,size_t count)
- {
- const unsigned char *su1, *su2;
- signed char res = 0;
- for( su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
- if ((res = *su1 - *su2) != 0)
- break;
- return res;
- }
-
-
-
-
- void * memscan(void * addr, unsigned char c, size_t size)
- {
- unsigned char * p = (unsigned char *) addr;
- while (size) {
- if (*p == c)
- return (void *) p;
- p++;
- size--;
- }
- return (void *) p;
- }
-
- void main(void)
- {
- return;
- }
-
-
补充strstr
- char* strstr (const char *haystack, const char *needle)
- {
- char *result = (char *)NULL;
- if ((haystack != (char *)NULL) && (needle != (char *)NULL))
- {
- register int i;
- int hl = strlen (haystack);
- int nl = strlen (needle);
- for (i = 0; i < (hl - nl); i++)
- if (strncmp (haystack + i, needle, nl) == 0)
- {
- result = haystack + i;
- break;
- }
- }
- return (result);
- }
还有 加州大学的:
- char *strstr(const char *string, const char *substring)
- {
- const char *a, *b;
- b = substring;
- if (*b == 0)
- {
- return (char*)string;
- }
- for( ; *string != 0; string += 1)
- {
- if (*string != *b)
- {
- continue;
- }
- a = string;
- while ((*a++ == *b++) && (*b != 0) );
- if (*b == 0)
- {
- return (char*) string;
- }
- b = substring;
- }
- }
最后是AT&T:
- extern char*
- strstr(register const char* s1, register const char* s2)
- {
- register int c1;
- register int c2;
- register const char* t1;
- register const char* t2;
- if (s2)
- {
- if (!*s2)
- return (char*)s1;
- c2 = *s2++;
- while (c1 = *s1++)
- if (c1 == c2)
- {
- t1 = s1;
- t2 = s2;
- do
- {
- if (!*t2)
- return (char*)s1 - 1;
- } while (*t1++ == *t2++);
- }
- }
- return 0;
- }
(andylin02) |