fopen

fopen_s、fscanf_s、fprintf_s、fclose

#include <stdio.h> #include <stdlib.h> FILE *stream; int main( void ) { long l; float fp; char s[81]; char c; errno_t err； err = fopen_s( &stream, "fscanf.out", "w+" ); // fopen的返回值是文件指针，而fopen_s的返回值是相应的错误代码，有助于排查问题 if( err ) printf_s( "The file fscanf.out was not opened\n" ); else { // 写入 fprintf_s( stream, "%s %ld %f%c", "a-string", 65000, 3.14159, 'x' ); // 设置文件指针指向文件头 fseek( stream, 0L, SEEK_SET ); // 读出 fscanf_s( stream, "%s", s, _countof(s) ); // 读字符串，要加上字符串长度参数 fscanf_s( stream, "%ld", &l ); // 读整数 fscanf_s( stream, "%f", &fp ); // 读浮点数 fscanf_s( stream, "%c", &c, 1 ); //读单个字符，注意要加上参数1 // Output data read: printf( "%s\n", s ); printf( "%ld\n", l ); printf( "%f\n", fp ); printf( "%c\n", c ); // 释放文件资源，关闭文件 fclose( stream ); } }