os/string.c
2024-05-21 18:41:16 +03:00

77 lines
1.2 KiB
C

#include "string.h"
#include <stddef.h>
int strcmp(const char *str1, const char *str2)
{
while (*str1 && (*str1 == *str2))
{
str1++;
str2++;
}
return *(const unsigned char *)str1 - *(const unsigned char *)str2;
}
char *strchr(const char *str, int c)
{
while (*str != '\0')
{
if (*str == c)
{
return (char *)str;
}
str++;
}
return NULL;
}
char *strtok(char *str, const char *delim)
{
static char *last_token = NULL;
char *token_start;
char *current;
if (str != NULL)
{
current = str;
}
else
{
current = last_token;
}
if (current == NULL)
{
return NULL;
}
while (*current != '\0' && strchr(delim, *current) != NULL)
{
current++;
}
if (*current == '\0')
{
last_token = NULL;
return NULL;
}
token_start = current;
while (*current != '\0' && strchr(delim, *current) == NULL)
{
current++;
}
if (*current != '\0')
{
*current = '\0';
last_token = current + 1;
}
else
{
last_token = NULL;
}
return token_start;
}