### 4.24 `fread`—read array elements from a file

Synopsis

         #include <stdio.h>
         size_t fread(void *buf, size_t size, size_t count,
             FILE *fp);

         #include <stdio.h>
         size_t _fread_r(struct _reent *ptr, void *buf,
             size_t size, size_t count, FILE *fp);

Description
`fread` attempts to copy, from the file or stream identified by fp, count elements (each of size size) into memory, starting at buf. `fread` may copy fewer elements than count if an error, or end of file, intervenes.

`fread` also advances the file position indicator (if any) for fp by the number of characters actually read.

`_fread_r` is simply the reentrant version of `fread` that takes an additional reentrant structure pointer argument: ptr.

Returns
The result of `fread` is the number of elements it succeeded in reading.

Portability
ANSI C requires `fread`.

Supporting OS subroutines required: `close`, `fstat`, `isatty`, `lseek`, `read`, `sbrk`, `write`.