getc_unlocked

Gets the next character from the stream.

Library:LibC
Classification:POSIX
Service:File and Directory I/O
Multithread Use:Unsafe

Syntax

  #include <stdio.h> 
   
  int getc_unlocked (
     FILE   *fp);

Parameters

fp

(IN) Points to the file object.

Return Values

If successful, returns the next byte from the input stream. Otherwise, if the stream is at end-of-file, returns EOF and sets the EOF indicator. If a read error occurs, returns EOF, sets the error indicator, and sets errno to one of the following:

Decimal

Constant

Description

4

EBADF

The file descriptor is not valid for reading.

5

ENOMEM

Insufficient storage space is available.

24

EAGAIN

The O_NONBLOCK flag is set for the file descriptor, and the process cannot immediately perform the read operation.

25

ENXIO

A request was made of a nonexistent device, or the request was outside the capabilities of the device.

28

EIO

The process is orphaned and cannot write to the file.

63

EINTR

A signal interrupted the read operation.

81

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.

Remarks

The getc_unlocked function is a non-thread safe version of the getc function. It should be used in a multi-threaded program only if it is called while the invoking thread owns the file object, as is the case after a successful call to the flockfile or ftrylockfile functions.

The character is returned as an int value.

See Also