fread and fwrite

size_t fread ( void buffer, size_t size, size_t count, FILE stream) ;
size_t fwrite(const void buffer, size_t size, size_t count, FILE stream);
buff:用于读写数据的内存地址
size:要读的每个数据项的字节数
count:要读多少个数据项
stream:文件流

getc and putc

int getc(FILE *stream);
int putc(int char, FILE *stream);
char:可以是字符，也可以是0-255的数据，比如10代表换行符
stream:文件流
返回值：如果到达文件末尾或发生读错误则返回EOF

fputs and fgets

char* fgets(char *buf, int bufsize, FILE *stream);
int fputs(const char *str, FILE *stream);
buff:用来存储所得数据的地址
buffsize:用来指明存储数据的大小
str:是一个数组，包含了要写入的以空字符终止的字符序列
stream:文件流

fscanf and fprintf

int fscanf(FILE *stream, const char *format, ...)
int fprintf(FILE *stream, const char *format, ...)
stream:文件流
format:%c, %d, %p,%s
example:fprintf(file, "%ld %ld %ld %ld %ld",mem->a[i].info,mem->a[i].x[0],mem->a[i].x[1],mem->a[i].x[2]);