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#include "string.h"
#include "errno.h"
#include "stdio.h"
extern "C" {
void bzero(void* dest, size_t n)
{
memset(dest, 0, n);
}
void bcopy(const void* src, void* dest, size_t n)
{
memmove(dest, src, n);
}
void* memset(void* dest, int c, size_t n)
{
uint8_t* bdest = (uint8_t*)dest;
for (; n; --n)
*(bdest++) = c;
return dest;
}
size_t strspn(const char* s, const char* accept)
{
const char* p = s;
cont:
char ch = *p++;
char ac;
for (const char* ap = accept; (ac = *ap++) != '\0';) {
if (ac == ch)
goto cont;
}
return p - 1 - s;
}
size_t strcspn(const char* s, const char* reject)
{
for (auto* p = s;;) {
char c = *p++;
auto* rp = reject;
char rc;
do {
if ((rc = *rp++) == c)
return p - 1 - s;
} while(rc);
}
}
size_t strlen(const char* str)
{
size_t len = 0;
while (*(str++))
++len;
return len;
}
int strcmp(const char* s1, const char* s2)
{
while (*s1 == *s2++)
if (*s1++ == 0)
return 0;
return *(const unsigned char*)s1 - *(const unsigned char*)--s2;
}
int strncmp(const char* s1, const char* s2, size_t n)
{
if (!n)
return 0;
do {
if (*s1 != *s2++)
return *(const unsigned char*)s1 - *(const unsigned char*)--s2;
if (*s1++ == 0)
break;
} while (--n);
return 0;
}
int memcmp(const void* v1, const void* v2, size_t n)
{
auto* s1 = (const uint8_t*)v1;
auto* s2 = (const uint8_t*)v2;
while (n-- > 0) {
if (*s1++ != *s2++)
return s1[-1] < s2[-1] ? -1 : 1;
}
return 0;
}
void memcpy(void* dest, const void* src, size_t n)
{
auto* bdest = (unsigned char*)dest;
auto* bsrc = (const unsigned char*)src;
for (; n; --n)
*(bdest++) = *(bsrc++);
}
char* strcpy(char* dest, const char *src)
{
char* originalDest = dest;
while ((*dest++ = *src++) != '\0');
return originalDest;
}
char* strncpy(char* dest, const char* src, size_t n)
{
size_t i;
for (i = 0; i < n && src[i] != '\0'; ++i)
dest[i] = src[i];
for ( ; i < n; ++i)
dest[i] = '\0';
return dest;
}
char* strchr(const char* str, int c)
{
if (!str)
return nullptr;
char* ptr = (char*)str;
while (*ptr && *ptr != c)
++ptr;
return ptr;
}
char* strrchr(const char* str, int ch)
{
char *last = nullptr;
char c;
for (; (c = *str); ++str) {
if (c == ch)
last = (char*)str;
}
return last;
}
char* strcat(char *dest, const char *src)
{
size_t destLength = strlen(dest);
size_t i;
for (i = 0 ; src[i] != '\0' ; i++)
dest[destLength + i] = src[i];
dest[destLength + i] = '\0';
return dest;
}
char* strncat(char *dest, const char *src, size_t n)
{
size_t destLength = strlen(dest);
size_t i;
for (i = 0 ; i < n && src[i] != '\0' ; i++)
dest[destLength + i] = src[i];
dest[destLength + i] = '\0';
return dest;
}
char* strerror(int errnum)
{
switch (errnum) {
case 0: return "No error";
case EPERM: return "Operation not permitted";
case ENOENT: return "No such file or directory";
case ESRCH: return "No such process";
case EINTR: return "Interrupted syscall";
case EIO: return "I/O error";
case ENXIO: return "No such device/address";
case E2BIG: return "Argument list too long";
case ENOEXEC: return "Exec format error";
case EBADF: return "Bad fd number";
case ECHILD: return "No child processes";
case EAGAIN: return "Try again";
case ENOMEM: return "Out of memory";
case EACCES: return "Access denied";
case EFAULT: return "Bad address";
case ENOTBLK: return "Not a block device";
case EBUSY: return "Resource busy";
case EEXIST: return "File already exists";
case EXDEV: return "Cross-device link";
case ENODEV: return "No such device";
case ENOTDIR: return "Not a directory";
case EISDIR: return "Is a directory";
case EINVAL: return "Invalid argument";
case ENFILE: return "File table overflow";
case EMFILE: return "Too many open files";
case ENOTTY: return "Not a TTY";
case ETXTBSY: return "Text file busy";
case EFBIG: return "File too big";
case ENOSPC: return "No space left";
case ESPIPE: return "Illegal seek";
case EROFS: return "File system is read-only";
case EMLINK: return "Too many links";
case EPIPE: return "Broken pipe";
case EDOM: return "Math argument out of domain";
case ERANGE: return "Math result not representable";
case ENAMETOOLONG: return "Name too long";
case EOVERFLOW: return "Value too large for data type";
case ENOTIMPL: return "Not implemented";
}
printf("strerror() missing string for errnum=%d\n", errnum);
return "Unknown error";
}
}
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