fread() -- read from stream

SYNOPSIS

#include <stdio.h>

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

The fread() function reads, into an array pointed to by ptr up to nitems members whose size is specified by size in bytes, from the stream pointed to by stream. 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 indeterminate. If a partial member is read, its value is indeterminate. A null byte does not necessarily terminate the sequence.

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

PARAMETERS

ptr: Points to the buffer where the data read is be held.
size: Is the size of one of the elements to be read.
nitems: Is the number of elements to be read.
stream: Points to the input stream.

RETURN VALUES

Upon successful completion, fread() returns the number of members 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, fread() returns EOF and sets errno to one of the following values:

EACCES: Another process has the file locked.
EAGAIN: The underlying file descriptor is in non-blocking mode, and the process would be delayed waiting for data to become available.
EBADF: stream is not a valid stream opened for reading.
EINTR: A signal interrupted the call.
EIO: An input error occurred.
EISDIR: The open object is a directory, not a file.
ENOMEM: Memory could not be allocated for internal buffers.
ENXIO: A device error occurred.
EOVERFLOW: The file is a regular file and an attempt was made to read at or beyond the offset maximum associated with the corresponding stream.
EWOULDBLOCK: The underlying file descriptor is a non-blocking socket and no data is ready to be read.

fread()
read from stream

Function

SYNOPSIS

DESCRIPTION

PARAMETERS

RETURN VALUES

CONFORMANCE

MULTITHREAD SAFETY LEVEL

PORTING ISSUES

AVAILABILITY

SEE ALSO

fread() read from stream

Function

fread()
read from stream