ferror : ferror « stdio.h « C Tutorial

1. C Tutorial
2. stdio.h
3. ferror

Use the perror() function to find out more about the error.

#include <stdio.h>
  #include <stdlib.h>

  int main(void){
     FILE *fp;

     if((fp=fopen("test", "rb"))==NULL) {
        printf("Cannot open file.\n");
        exit(1);
     }

     putc('C', fp);
     if(ferror(fp)) {
       printf("File Error\n");
       exit(1);
     }
    
     fclose(fp);
     return 0;
  }