kern
annotate src/klibc/string.c @ 67:ebca81749ef5
added strcmp
| author | John Tsiombikas <nuclear@mutantstargoat.com> |
|---|---|
| date | Sun, 09 Oct 2011 20:38:35 +0300 |
| parents | af6f4adc43d6 |
| children | f83f50c17c3b |
| rev | line source |
|---|---|
| nuclear@0 | 1 #include <string.h> |
| nuclear@0 | 2 |
| nuclear@1 | 3 void memset(void *s, int c, size_t n) |
| nuclear@0 | 4 { |
| nuclear@0 | 5 char *ptr = s; |
| nuclear@1 | 6 while(n--) { |
| nuclear@0 | 7 *ptr++ = c; |
| nuclear@0 | 8 } |
| nuclear@0 | 9 } |
| nuclear@1 | 10 |
| nuclear@4 | 11 /* Does the same thing as memset only with 16bit values. |
| nuclear@4 | 12 * n in this case is the number of values, not the number of bytes. |
| nuclear@4 | 13 */ |
| nuclear@2 | 14 void memset16(void *s, int c, size_t n) |
| nuclear@2 | 15 { |
| nuclear@2 | 16 short *ptr = s; |
| nuclear@2 | 17 while(n--) { |
| nuclear@2 | 18 *ptr++ = c; |
| nuclear@2 | 19 } |
| nuclear@2 | 20 } |
| nuclear@2 | 21 |
| nuclear@1 | 22 void *memcpy(void *dest, const void *src, size_t n) |
| nuclear@1 | 23 { |
| nuclear@1 | 24 char *dptr = dest; |
| nuclear@1 | 25 const char *sptr = src; |
| nuclear@1 | 26 |
| nuclear@1 | 27 while(n--) { |
| nuclear@1 | 28 *dptr++ = *sptr++; |
| nuclear@1 | 29 } |
| nuclear@1 | 30 return dest; |
| nuclear@1 | 31 } |
| nuclear@1 | 32 |
| nuclear@1 | 33 void *memmove(void *dest, const void *src, size_t n) |
| nuclear@1 | 34 { |
| nuclear@1 | 35 int i; |
| nuclear@1 | 36 char *dptr; |
| nuclear@1 | 37 const char *sptr; |
| nuclear@1 | 38 |
| nuclear@1 | 39 if(dest <= src) { |
| nuclear@1 | 40 /* forward copy */ |
| nuclear@1 | 41 dptr = dest; |
| nuclear@1 | 42 sptr = src; |
| nuclear@1 | 43 for(i=0; i<n; i++) { |
| nuclear@1 | 44 *dptr++ = *sptr++; |
| nuclear@1 | 45 } |
| nuclear@1 | 46 } else { |
| nuclear@1 | 47 /* backwards copy */ |
| nuclear@1 | 48 dptr = dest + n - 1; |
| nuclear@1 | 49 sptr = src + n - 1; |
| nuclear@1 | 50 for(i=0; i<n; i++) { |
| nuclear@1 | 51 *dptr-- = *sptr--; |
| nuclear@1 | 52 } |
| nuclear@1 | 53 } |
| nuclear@1 | 54 |
| nuclear@1 | 55 return dest; |
| nuclear@1 | 56 } |
| nuclear@5 | 57 |
| nuclear@5 | 58 size_t strlen(const char *s) |
| nuclear@5 | 59 { |
| nuclear@5 | 60 size_t len = 0; |
| nuclear@5 | 61 while(*s++) len++; |
| nuclear@5 | 62 return len; |
| nuclear@5 | 63 } |
| nuclear@5 | 64 |
| nuclear@5 | 65 char *strchr(const char *s, int c) |
| nuclear@5 | 66 { |
| nuclear@5 | 67 while(*s) { |
| nuclear@5 | 68 if(*s == c) { |
| nuclear@9 | 69 return (char*)s; |
| nuclear@5 | 70 } |
| nuclear@5 | 71 s++; |
| nuclear@5 | 72 } |
| nuclear@5 | 73 return 0; |
| nuclear@5 | 74 } |
| nuclear@5 | 75 |
| nuclear@5 | 76 char *strrchr(const char *s, int c) |
| nuclear@5 | 77 { |
| nuclear@9 | 78 const char *ptr = s; |
| nuclear@5 | 79 |
| nuclear@5 | 80 /* find the end */ |
| nuclear@5 | 81 while(*ptr) ptr++; |
| nuclear@5 | 82 |
| nuclear@5 | 83 /* go back checking for c */ |
| nuclear@9 | 84 while(--ptr >= s) { |
| nuclear@5 | 85 if(*ptr == c) { |
| nuclear@9 | 86 return (char*)ptr; |
| nuclear@5 | 87 } |
| nuclear@5 | 88 } |
| nuclear@5 | 89 return 0; |
| nuclear@5 | 90 } |
| nuclear@67 | 91 |
| nuclear@67 | 92 int strcmp(const char *s1, const char *s2) |
| nuclear@67 | 93 { |
| nuclear@67 | 94 while(*s1 && *s1 == *s2) { |
| nuclear@67 | 95 s1++; |
| nuclear@67 | 96 s2++; |
| nuclear@67 | 97 } |
| nuclear@67 | 98 return *s1 - *s2; |
| nuclear@67 | 99 } |