65 lines
1.4 KiB
C
65 lines
1.4 KiB
C
#include <string.h>
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size_t strlen(const char *s) {
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int i = 0;
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while(s[i] != '\0') {
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i++;
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}
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return i;
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}
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void *memmove(void *dest, const void *src, size_t n) {
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unsigned char* chardest = dest;
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const unsigned char* charsrc = src;
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if (chardest == charsrc) {
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return (void*)chardest;
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} else if (chardest > charsrc) {
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for (size_t i = n; i > sizeof(charsrc); i--)
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chardest[i] = charsrc[i];
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} else {
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for (int i = 0; i < chardest - charsrc; i++)
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chardest[i] = charsrc[i];
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}
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memcpy(chardest, charsrc, n);
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return (void*)chardest;
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}
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int memcmp(const void *s1, const void *s2, size_t n) {
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int status = sizeof(s1) - sizeof(s2);
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if (status > 0 || status < 0) {
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return status;
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} else {
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const unsigned char* first = s1;
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const unsigned char* second = s2;
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for (size_t i = 0; i < n; i++) {
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if (first[i] != second[i])
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return first[i] - second[i];
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}
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return 0;
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}
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}
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void *memset(void *s, int c, size_t n) {
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unsigned char uc = c;
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unsigned char* ss = s;
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for (size_t i = 0; i < n; i++)
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ss[i] = uc;
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return (void*)ss;
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}
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void *memcpy(void *restrict dest, const void *restrict src, size_t n) {
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size_t i;
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unsigned char* chardest = dest;
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const unsigned char* charsrc = src;
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for (i = 0; i < n && charsrc[i] != '\0'; i++) {
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chardest[i] = charsrc[i];
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}
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for (; i < n; i++) {
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chardest[i] = '\0';
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}
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return (void*)chardest;
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}
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