C/stdio.h/ferror
ferror: check for a file error
//Declaration: int ferror(FILE *stream);
//Return: 0: no error has occurred.
Nonzero: an error has occurred.
#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;
}