将文本文件fin.dat中的数字字符找出并写入文本文件fnum.dat中。
#include
void main ()
{
char ch;
FILE *fin, *fnum;
fin=fopen ("fin.dat", __________); /*第一空*/
fnum=fopen ("fnum.dat", "w");
while(!feof(__________)) /*第二空*/
{
ch=fgetc(fin);
if(__________)fputc (ch, fnum); /*第三空*/
}
fclose (fin);
fclose(fnum);
}