状态机解析字符串

#include 
#include 

#ifdef DEBUG
#define PRINT printf
#else
#define PRINT
#endif
typedef void (*ACT)(void);

static char buf[64];
static int j ;
static char c;

int find_type(char key)
{
		if(key >= 'a' && key <= 'z')
					return 1; // 小写字符
			if(key >= 'A' && key <= 'Z')
						return 1; // 大写字符
				if(key >= '0' && key <= '9')
							return 2; // 数字
				if(key == '\0')
					return 3;  // 结束

					return 0;  //  其他

}
void act_body(void)
{
	buf[j++] = c;
}
void act_tail(void)
{
	PRINT("word tail found\n");
	buf[j] = '\0';
	printf("word is %s \n", buf);	

}
void act_tail2(void)
{
	PRINT("word tail found\n");
	buf[j] = '\0';
	printf("number is %s \n", buf);	
}

void act_head(void)
{
	PRINT("word head found!\n");
	j = 0;
	buf[j++] = c;
}

void act_null(void)
{
	return;
}
void act_end_begin()
{
	act_tail();
	act_head();
}
void act_end2_begin()
{
	act_tail2();
	act_head();
}

ACT acts[3][4] = {
	act_null, act_head,act_head, act_null,
	act_tail, act_body, act_end_begin,  act_tail,
	act_tail2, act_end2_begin, act_body, act_tail2,
};

int state_trans[3][4] = {
	0, 1, 2, -1,
	0, 1, 2, -1,
	0, 1, 2, -1,
};

int main(void)
{
	int state = 0;
	int i = 0;
	char *str = "hello, 123, hello worlda 567";

	printf("%s\n", str);

	while(state != -1)
	{
		int input;
		c = str[i];
		input = find_type(c);
		acts[state][input]();

		state = state_trans[state][input];
	i++;
	}
		return 0;

}


#if 0
		switch(state)
		{
		case 0://" "
				switch (input)
				{
				case 0:// " "
					state = 0;
					act_null();
					break;
				case 1:// "a"
					state = 1;
					act_head();
					break;
				case 2:// "\0"
					state = -1;
					act_null();
					break;
				}
			break;
		case 1://"a"
				switch(input)
				{
				case 0:// " "
					state = 0;
					act_tail();
					break;
				case 1:// "a"
					state = 1;
					act_body();
					break;
				case 2:// "\0"
					state = -1;
					act_tail();
					break;
				}
			break;

		default :
			break;
		}
		
		i++;
	}
	printf("\n");

	return 0;
}
#endif

　　

转载于:https://www.cnblogs.com/mathzzz/archive/2012/09/02/2667815.html