mirror of https://github.com/AxioDL/kabufuda.git
35 lines
906 B
C++
35 lines
906 B
C++
#include <cstdlib>
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#include <cstdint>
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#include <cstring>
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#include <string>
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#include "hecl/winsupport.hpp"
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/*
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* The memmem() function finds the start of the first occurrence of the
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* substring 'needle' of length 'nlen' in the memory area 'haystack' of
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* length 'hlen'.
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*
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* The return value is a pointer to the beginning of the sub-string, or
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* NULL if the substring is not found.
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*/
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void* memmem(const void* haystack, size_t hlen, const void* needle, size_t nlen) {
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int needle_first;
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const uint8_t* p = static_cast<const uint8_t*>(haystack);
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size_t plen = hlen;
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if (!nlen)
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return NULL;
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needle_first = *(unsigned char*)needle;
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while (plen >= nlen && (p = static_cast<const uint8_t*>(memchr(p, needle_first, plen - nlen + 1)))) {
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if (!memcmp(p, needle, nlen))
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return (void*)p;
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p++;
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plen = hlen - (p - static_cast<const uint8_t*>(haystack));
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}
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return NULL;
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}
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