fdclose(3)

fdclose3

Close a stream

Part of fclose(3).

Usage

#include <stdio.h>

int

fclose(FILE *stream);

int

fdclose(FILE *stream, int *fdp);

void

fcloseall(void);

Library

Standard C Library (libc, -lc)

Overview

The fclose() function dissociates the named stream from its underlying file or set of functions. If the stream was being used for output, any buffered data is written first, using fflush(3).

The fdclose() function is equivalent to fclose() except that it does not close the underlying file descriptor. If fdp is not NULL, the file descriptor will be written to it. If the stream does not have an associated file descriptor, fdp will be set to -1. This type of stream is created with functions such as fmemopen(3), funopen(3), or open_memstream(3).

The fcloseall() function calls fclose() on all open streams.

Return values

fcloseall() does not return a value.

Upon successful completion the fclose() and fdclose() functions return 0. Otherwise, EOF is returned and the global variable errno is set to indicate the error.

Errors

fdclose() fails if:

[EOPNOTSUPP]

The stream does not have an associated file descriptor.

The fclose() and fdclose() functions may also fail and set errno for any of the errors specified for fflush(3).

The fclose() function may also fail and set errno for any of the errors specified for close(2).

Notes

The fclose() and fdclose() functions do not handle NULL arguments in the stream variable; this will result in a segmentation violation. This is intentional. It makes it easier to make sure programs written under FreeBSD are bug free. This behaviour is an implementation detail, and programs should not rely upon it.

Releases

25 releases since FreeBSD 11.0-RELEASE; the text changed 12 times.

  1. 11.0
  2. 11.1
  3. 11.2
  4. 11.3
  5. 11.4
  6. 12.0
  7. 12.1
  8. 12.2
  9. 12.3
  10. 12.4
  11. 13.0–13.2
  12. 13.3–14.5
  13. 15.0–16.0

Standards

The fclose() function conforms to ISO/IEC 9899:1990 (“ISO C90”).

History

The fcloseall() function first appeared in FreeBSD 7.0.

The fdclose() function first appeared in FreeBSD 11.0.

From base 16.0-CURRENT-20261027-61c70dc16a79 in FreeBSD 16.0-CURRENT (2026-10-27). Parsed by carta from the page's mdoc source.