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/*
* Copyright (C) 2025 Danny Holman <dholman@gymli.org>
*
* This file is part of BoxOS, a free and open-source Unix-like operating
* system.
*
* BoxOS is free software; you can redistribute it and/or modify under the
* terms of the GNU General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option) any later
* version.
*
* BoxOS is distributed in the hope it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
* PARTICULAR PURPOSE. See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along with
* BoxOS; if not, see <https://www.gnu.org/licenses/>.
*/
#include <string.h>
int memcmp(const void *str1, const void *str2, size_t n) {
unsigned char const *p1 = str1;
unsigned char const *p2 = str2;
int ret = 0;
if (str1 == str2)
return 0;
while (n > 0) {
if (*p1 != *p2) {
ret = (*p1 > *p2)?1:-1;
break;
}
n--;
p1++;
p2++;
}
return ret;
}
void* memcpy(void* __restrict dest, const void* __restrict src, size_t n) {
if (dest == src)
return dest;
unsigned char *pdest = dest;
unsigned char const *psrc = src;
for (size_t i = 0; i < n; i++)
pdest[i] = psrc[i];
return dest;
}
char* strncpy(char* __restrict dest, const char* __restrict src, size_t n) {
for (size_t i = 0; i < n; i++) {
if (src[i] == '\0')
break;
dest[i] = src[i];
}
return dest;
}
char* strcpy(char* __restrict dest, const char* __restrict src) {
return (char*)memcpy(dest, src, strlen(src));
}
char* strcat(char* __restrict dest, const char* __restrict src) {
return (char*)memcpy(&dest[strlen(dest)], src, strlen(src));
}
char* strncat(char* __restrict dest, const char* __restrict src, size_t n) {
return (char*)memcpy(&dest[strlen(dest)], src, n);
}
void* memmove(void* __restrict dest, const void* __restrict src, size_t n) {
if (dest == src)
return dest;
unsigned char const *psrc = src;
unsigned char buffer[n];
for (size_t i = 0; i < n; i++)
buffer[i] = psrc[i];
return memcpy(dest, (void*)buffer, n);
}
void* memset(void *str, int c, size_t n) {
unsigned char *p = str;
for (size_t i = 0; i < n; i++)
p[i] = (unsigned char)c;
return str;
}
int strncmp(const char *str1, const char *str2, size_t n) {
return memcmp(str1, str2, n);
}
int strcmp(const char *str1, const char *str2) {
size_t str1_sz = strlen(str1);
size_t str2_sz = strlen(str2);
if (str1_sz > str2_sz)
return memcmp(str1, str2, str2_sz);
return memcmp(str1, str2, str1_sz);
}
size_t strlen(const char *str) {
size_t i = 0;
while (str[i] != '\0')
i++;
return i;
}
int _is_delim(char c, const char *delim) {
while (*delim != '\0') {
if (c == *delim)
return 1;
delim++;
}
return 0;
}
char* strtok(char* __restrict str, const char* __restrict delim) {
static char *old_str;
if (str == NULL)
str = old_str;
while (1) {
if (_is_delim(*str, delim)) {
str++;
continue;
}
if (*str == '\0')
return NULL;
break;
}
char *ret = str;
while (1) {
if (*str == '\0') {
old_str = str;
return ret;
}
if (_is_delim(*str, delim)) {
*str = '\0';
old_str = str + 1;
return ret;
}
str++;
}
}
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