fscanf

函数名: fscanf 　　

功 能: 从一个流中执行格式化输入 　
　
用 法: int fscanf(FILE *stream, char *format,[argument...]); 　
　
int fscnf(文件指针，格式字符串，输入列表); 　
　
返回值：整型，数值等于[argument...]的个数 　
　
程序例: 　　

#include 　　
#include 　　

int main(void) 　　
{ 　
         int i; 　　printf("Input an integer: "); 　　/* read an integer from the 　　standard input stream */ 　　        if (fscanf(stdin, "%d", &i)) 　　
               printf("The integer read was: %d\n", 　　i); 　　
        else 　　
       { 　　
               fprintf(stderr, "Error reading an \ 　　integer from stdin.\n"); 　　exit(1); 　　
        } 　　
        return 0; 　　
} 　　
返回EOF如果读取到文件结尾。 　　
常用基本参数对照： 　　
'%d' : Scan an integer as a signed decimal number. 　　
'%i' : Scan an integer as a signed number. Similar to '%d', but interprets the number as hexadecimal when preceded by "0x" and octal when preceded by "0". For example, the string "031" would be read as 31 using '%d', and 25 using '%i'. 　　
'%u' : Scan for decimal unsigned int, unsigned short, and unsigned char 　　
'%f' : Scan a floating-point number in normal (fixed-point) notation. 　　
'%g', '%G' : Scan a floating-point number in either normal or exponential notation.
'%g' uses lower-case letters and '%G' uses upper-case.
'%x', '%X' : Scan an integer as an unsigned hexadecimal number. 　　
'%o' : Scan an integer as an octal number. 　　
'%s' : Scan a character string. The scan terminates at whitespace. A null character is stored at the end of the string, which means that the buffer supplied must be at least one character longer than the specified input length. 　　
'%c' : Scan a character (char). No null character is added.'(space)': Space scans for whitespace characters. 　　
'%lf' : Scan as a double floating-point number. 　　
'%Lf' : Scan as a long double floating-point number. 　　
附：MSDN中例子 　　
Example 　　/* FSCANF.C: This program writes formatted 　　* data to a file. It then uses fscanf to 　　* read the various data back from the file. 　　*/
 　　
#include 　　
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 ); 　　
            } 　　
}