fwrite_unlo(3s) [hpux man page]

fread(3S)																 fread(3S)

NAME

       fread(), fwrite() - buffered binary input/output to a stream file

SYNOPSIS

   Obsolescent Interfaces
DESCRIPTION

       copies,	into  an  array  pointed to by ptr, up to nitems items of data from the named input stream, where an item of data is a sequence of
       bytes (not necessarily terminated by a null byte) of length size.  stops appending bytes if an end-of-file or error  condition  is  encoun-
       tered while reading stream, or if nitems items have been read.  leaves the file pointer in stream, if defined, pointing to the byte follow-
       ing the last byte read if there is one.	does not change the contents of stream.

       appends at most nitems items of data from the array pointed to by ptr to the named output stream.  stops appending  when  it  has  appended
       nitems items of data or if an error condition is encountered on stream.	does not change the contents of the array pointed to by ptr.

       The argument size is typically where the pseudo-function specifies the length of an item pointed to by ptr.

   Obsolescent Interfaces
       and buffered binary input/output to a stream file.

APPLICATION USAGE

       After or is applied to a stream, the stream becomes byte-oriented (see orientation(5)).

RETURN VALUE

       and return the number of items read or written.	If size or nitems is 0, no characters are read or written and 0 is returned.

       The value returned will be less than nitems only if a read error or end-of-file is encountered.

       When  the file corresponding to an open stream gets extended after the end-of-file is reached, any subsequent calls to will succeed and the
       end-of-file indicator will remain set.  However, in the UNIX2003 standards environment (see standards(5)), this function will  return  zero
       and the end-of-file indicator will remain set.

       The or functions must be used to distinguish between an error condition and an end-of-file condition.

ERRORS

       Refer to getc(3S) for a description of errors returned by

       Refer to putc(3S) for a description of errors returned by

WARNINGS

       and  are obsolescent interfaces supported only for compatibility with existing DCE applications.  New multithreaded applications should use
       and

SEE ALSO

       read(2), write(2), fopen(3S), flockfile(3S), getc(3S), gets(3S), printf(3S), putc(3S), puts(3S), scanf(3S),  orientation(5),  standards(5),
       thread_safety(5), glossary(9).

STANDARDS CONFORMANCE

																	 fread(3S)

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 5.11							    24 Jul 2002 							 fread(3C)