sunos man page for fread

fread(3C)						   Standard C Library Functions 						 fread(3C)

NAME
       fread - binary input

SYNOPSIS
       #include <stdio.h>

       size_t fread(void *ptr, size_t size, size_t nitems, FILE *stream);

DESCRIPTION
       The fread() function reads into the array pointed to by ptr up to nitems elements whose size is specified by size in bytes, from the stream
       pointed to by stream. For each object, size calls are made to the fgetc(3C) function and the results stored, in the order read, in an array
       of  unsigned char exactly overlaying the object. The file-position indicator for the stream (if defined) is advanced by the number of bytes
       successfully read. If an error occurs, the resulting value of the file-position indicator for the stream is unspecified. If a partial  ele-
       ment is read, its value is unspecified.

       The  fread()  function  may  mark  the  st_atime field of the file associated with stream for update. The st_atime field will be marked for
       update by the first successful execution of fgetc(3C), fgets(3C),  fgetwc(3C),  fgetws(3C),  fread(),  fscanf(3C),  getc(3C),  getchar(3C),
       gets(3C), or scanf(3C) using stream that returns data not supplied by a prior call to ungetc(3C) or ungetwc(3C).

RETURN VALUES
       Upon  successful  completion,  fread()  returns the number of elements successfully read, which is less than nitems only if a read error or
       end-of-file is encountered. If size or nitems is 0, fread() returns 0 and the contents of the array and the  state  of  the  stream  remain
       unchanged.  Otherwise, if a read error occurs, the error indicator for the stream is set and errno is set to indicate the error.

ERRORS
       Refer to fgetc(3C).

EXAMPLES
       Example 1: Reading from a Stream

       The following example reads a single element from the fp stream into the array pointed to by buf.

       #include <stdio.h>
       ...
       size_t bytes_read;
       char buf[100];
       FILE *fp;
       ...
       bytes_read = fread(buf, sizeof(buf), 1, fp);
       ...

USAGE
       The ferror() or feof() functions must be used to distinguish between an error condition and end-of-file condition. See ferror(3C).

       Because of possible differences in element length and byte ordering, files written using fwrite(3C) are application-dependent, and possibly
       cannot be read using fread() by a different application or by the same application on a different processor.

ATTRIBUTES
       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO
       read(2), fclose(3C), ferror(3C), fopen(3C), getc(3C), gets(3C), printf(3C), putc(3C), puts(3C), attributes(5), standards(5)

SunOS 5.10							    24 Jul 2002 							 fread(3C)