FCLOSE(P) POSIX Programmer's Manual FCLOSE(P)
fclose - close a stream
int fclose(FILE *stream);
The fclose() function shall cause the stream pointed to by stream to be flushed and the
associated file to be closed. Any unwritten buffered data for the stream shall be written
to the file; any unread buffered data shall be discarded. Whether or not the call suc-
ceeds, the stream shall be disassociated from the file and any buffer set by the setbuf()
or setvbuf() function shall be disassociated from the stream. If the associated buffer was
automatically allocated, it shall be deallocated.
The fclose() function shall mark for update the st_ctime and st_mtime fields of the under-
lying file, if the stream was writable, and if buffered data remains that has not yet been
written to the file. The fclose() function shall perform the equivalent of a close() on
the file descriptor that is associated with the stream pointed to by stream.
After the call to fclose(), any use of stream results in undefined behavior.
Upon successful completion, fclose() shall return 0; otherwise, it shall return EOF and
set errno to indicate the error.
The fclose() function shall fail if:
EAGAIN The O_NONBLOCK flag is set for the file descriptor underlying stream and the
process would be delayed in the write operation.
EBADF The file descriptor underlying stream is not valid.
EFBIG An attempt was made to write a file that exceeds the maximum file size.
EFBIG An attempt was made to write a file that exceeds the process' file size limit.
EFBIG The file is a regular file and an attempt was made to write at or beyond the offset
maximum associated with the corresponding stream.
EINTR The fclose() function was interrupted by a signal.
EIO The process is a member of a background process group attempting to write to its
controlling terminal, TOSTOP is set, the process is neither ignoring nor blocking
SIGTTOU, and the process group of the process is orphaned. This error may also be
returned under implementation-defined conditions.
ENOSPC There was no free space remaining on the device containing the file.
EPIPE An attempt is made to write to a pipe or FIFO that is not open for reading by any
process. A SIGPIPE signal shall also be sent to the thread.
The fclose() function may fail if:
ENXIO A request was made of a nonexistent device, or the request was outside the capabil-
ities of the device.
The following sections are informative.
close() , fopen() , getrlimit() , ulimit() , the Base Definitions volume of
IEEE Std 1003.1-2001, <stdio.h>
Portions of this text are reprinted and reproduced in electronic form from IEEE Std
1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System
Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by
the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and The Open Group
Standard, the original IEEE and The Open Group Standard is the referee document. The orig-
inal Standard can be obtained online at http://www.opengroup.org/unix/online.html .
IEEE/The Open Group 2003 FCLOSE(P)