C库函数 ferror()

#include <stdio.h>



int main () {

   FILE *fp;

   char c;



   fp = fopen("file.txt", "w");



   c = fgetc(fp);

   if( ferror(fp) ) {

      printf("Error in reading from file : file.txt\n");

   }

   clearerr(fp);



   if( ferror(fp) ) {

      printf("Error in reading from file : file.txt\n");

   }

   fclose(fp);



   return(0);

}