C coding check list

1 pointer set NULL

2 pointer memset must set specify Number, can not use  sizeof
    char *jason = NULL;
    jason = malloc( 99999 );
    memset(jason, '\0', 99999);  //OK

   // memset(jason, '\0', sizeof(jason));  //NG

3  If malloc, must free after used.

4  file pointer must close before return.

   FILE *fp 
   if(fp!=NULL)
      fclose(fp);
   return 0;