fscanf函数 - 爱码网

函数定义：

int fscanf( FILE *stream, const char *format [, argument ]... );

以下是csdn的样例：

/* FSCANF.C: This program writes formatted
 * data to a file. It then uses fscanf to
 * read the various data back from the file.
 */

#include <stdio.h>

FILE *stream;

void main( void )
{
   long l;
   float fp;
   char s[81];
   char c;

   stream = fopen( "fscanf.out", "w+" );
   if( stream == NULL )
      printf( "The file fscanf.out was not opened\n" );
   else
   {
      fprintf( stream, "%s %ld %f%c", "a-string", 
               65000, 3.14159, 'x' );

      /* Set pointer to beginning of file: */
      fseek( stream, 0L, SEEK_SET );

      /* Read data back from file: */
      fscanf( stream, "%s", s );
      fscanf( stream, "%ld", &l );

      fscanf( stream, "%f", &fp );
      fscanf( stream, "%c", &c );

      /* Output data read: */
      printf( "%s\n", s );
      printf( "%ld\n", l );
      printf( "%f\n", fp );
      printf( "%c\n", c );

      fclose( stream );
   }
}

Output
a-string
65000
3.141590
x

以下给出一个样例，结合相似的几个函数操作。（也是文件的一般操作）

1 写操作函数

#include<stdio.h> 
     main() 
     { 
          char *s="That's good news");  /*定义字符串指针并初始化*/ 
          int i=617;                    /*定义整型变量并初始化*/ 
          FILE *fp;                     /*定义文件指针*/ 
          fp=fopne("test.dat", "w");    /*建立一个文字文件仅仅写*/ 
          fputs("Your score of TOEFLis", fp);/*向所建文件写入一串字符*/ 
          fputc(':', fp);               /*向所建文件写冒号:*/ 
          fprintf(fp, "%d\n", i);       /*向所建文件写一整型数*/ 
          fprintf(fp, "%s", s);         /*向所建文件写一字符串*/ 
          fclose(fp);                   /*关闭文件*/ 
     }

运行以后：

test.dat 为一个文件：

里面内容为：

Your score of TEFLis:617

That's good news

2 读操作函数

运行效果例如以下：

Your score of TOEFL is: 617
That's good news