フォーマットされた文字列の入力と出力

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
void test01(){
	char buf[1024];
	memset(buf, 0, 1024);
	sprintf(buf,"今天是%d年%月%d日\n",2019,10,21);
	printf("%s", buf);

	//字符串拼接
	memset(buf, 0, 1024);
	char str1[] = "hello";
	char str2[] = "world";
	int len = sprintf(buf,"%s%s",str1,str2);
	printf("buf:%s len:%d\n",buf,len);

	//数字转字符串
	memset(buf,0,1024);
	int num = 100;
	sprintf(buf,"%d",num);
	printf("buf:%s\n",buf);

	//设置宽度 右对齐
	memset(buf,0,1024);
	sprintf(buf,"%8d",num);
	printf("buf:%s\n",buf);

	//设置宽度 左对齐
	memset(buf, 0, 1024);
	sprintf(buf, "%-8d", num);
	printf("buf:%sa\n", buf);

	//转成8进制字符串
	memset(buf,0,1024);
	sprintf(buf,"0%o",num);
	printf("buf:%s\n",buf);
}

int main(){
	test01();
	return 0;
}

sscanfは

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<stdlib.h>
#include<string.h>

//1.%*s或%*d 跳过数据
void test01(){
	char *str = "12345abcde";
	char buf[1024] = {0};
	sscanf(str,"%*d%s",buf); //abcde
	printf("%s\n",buf);
}

void test02(){
	char *str = "abcde123456";
	char buf[1024] = {0};
	//sscanf(str,"%*s%s",buf);
	sscanf(str,"%*[a-z]%s",buf);//123456
	printf("%s\n",buf);
}

//2.%[width]s 读取指定宽度的数据
void test03(){
	char *str = "12345abcde";
	char buf[1024] = { 0 };
	sscanf(str,"%6s",buf);//12345a
	printf("%s\n",buf);
}

//3.%[a-z] 匹配a到z中任意字符（尽可能多的匹配）
void test04(){
	char *str = "12345abcde";
	char buf[1024] = { 0 };
	sscanf(str,"%*d%[a-z]",buf);//abcde
	printf("%s\n",buf);
}

//4.%[aBc] 匹配a,B,c中一员，贪婪性
void test05(){
	char *str = "aacde12345";
	char buf[1024] = { 0 };
	sscanf(str,"%[aBc]",buf);//aac，匹配过程中只要失败停止匹配
	printf("%s\n",buf);
}

//5.%[^a] 匹配非a的任意字符，贪婪性
void test06(){
	char *str = "abcde12345";
	char buf[1024] = { 0 };
	sscanf(str,"%[^c]",buf); //ab 匹配过程一失败就停止匹配
	printf("%s\n",buf);
}

//6. %[^a-z] 表示读取除了a-z以外的所有字符
void test07(){
	char *str = "abcde12345";
	char buf[1024] = { 0 };
	sscanf(str,"%[^0-9]",buf);//abcde
	printf("%s\n",buf);
}

//7.案例
void test08(){
	char *ip = "127.0.0.1";
	int num1 = 0;
	int num2 = 0;
	int num3 = 0;
	int num4 = 0;
	sscanf(ip,"%d.%d.%d.%d",&num1,&num2,&num3,&num4);
	printf("%d\n", num1);
	printf("%d\n", num2);
	printf("%d\n", num3);
	printf("%d\n", num4);
}

void test09(){
	char *str = "abced#zhangtao@12345";
	char buf[1024] = { 0 };
	sscanf(str,"%*[^#]#%[^@]",buf);//zhangtao
	printf("%s\n",buf);
}

void test10(){
//已给定字符串为: [email protected],
//请编码实现helloworld输出和com.cn
	char *str = "[email protected]";
	char buf1[1024] = { 0 };
	char buf2[1024] = { 0 };
	sscanf(str,"%[a-z]%*[@]%s",buf1,buf2);
	printf("%s\n",buf1);
	printf("%s\n",buf2);
}
int main(){
	test10();
	return 0;
}