函数名: fprintf 
 功  能: 传送格式化输出到一个流中 
 用  法: #include <stdio.h>
         int fprintf(FILE *stream, char *format[, argument,...]); 
 程序例: 
/* Program to create backup of the 
    AUTOEXEC.BAT file */ 
#include <stdio.h>
int main(void) 
 { 
    FILE *in, *out; 
   if ((in = fopen("\\AUTOEXEC.BAT", "rt")) 
        == NULL) 
    { 
       fprintf(stderr, "Cannot open input \ 
        file.\n"); 
       return 1; 
    } 
   if ((out = fopen("\\AUTOEXEC.BAK", "wt")) 
        == NULL) 
    { 
       fprintf(stderr, "Cannot open output \ 
        file.\n"); 
       return 1; 
    } 
   while (!feof(in)) 
       fputc(fgetc(in), out); 
   fclose(in); 
    fclose(out); 
    return 0; 
 }