C/C++中scanf、sscanf、fscanf函数用法

#include <stdio.h>#include <stdlib.h>int main(int atgc, int *argv[]){int a;char buf[100] = {0};FILE *file = NULL;printf("请输入一个数字：");scanf("%d", &a);printf("a = %dn", a);sscanf("123456", "%2d", &a);sscanf("abcdef", "%4s", buf); // 取指定长度的字符串printf("a = %dnbuf:%sn", a, buf);//取到指定字符为止的字符串sscanf("123456 abcdedf", "%[^ ]", buf); //取遇到空格为止字符串printf("取到指定字符为止的字符串:%sn", buf);sscanf("123456abcdedfBCDEF", "%[^A-Z]", buf); //取遇到大写字母为止的字符串printf("取到指定字符为止的字符串:%sn", buf);// 取仅包含指定字符集的字符串sscanf("123456abcdedfBCDEF", "%[1-9a-z]", buf); //取仅包含1到9和小写字母的字符串printf("取仅包含指定字符集的字符串:%sn", buf);//获取两个指定字符之间的字符串sscanf("iios/12DDWDFF@122", "%*[^/]/%[^@]", buf);printf("取两个指定字符之间的字符串:%sn", buf);//给定一个字符串"hello, world"，仅保留"world"sscanf("hello, world", "%*s%s", buf); // %*s表示第一个匹配到的%s被过滤掉printf("%sn", buf);//从文件中读取file = fopen("hello.txt", "r");if(NULL!= file){fscanf(file, "%s", buf);printf("从文件中读取：%sn", buf);}fclose(file);return 0;}