xref: /freebsd/lib/libc/stdio/fclose.3 (revision 1250c9647959fab955fb8d9046cb41bc749e6855)

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.Dd February 13, 2024
.Dt FCLOSE 3
.Os
.Sh NAME
.Nm fclose ,
.Nm fdclose ,
.Nm fcloseall
.Nd close a stream
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In stdio.h
.Ft int
.Fn fclose "FILE *stream"
.Ft int
.Fn fdclose "FILE *stream" "int *fdp"
.Ft void
.Fn fcloseall void
.Sh DESCRIPTION
The
.Fn fclose
function
dissociates the named
.Fa stream
from its underlying file or set of functions.
If the stream was being used for output, any buffered data is written
first, using
.Xr fflush 3 .
.Pp
The
.Fn fdclose
function is equivalent to
.Fn fclose
except that it does not close the underlying file descriptor.
If
.Fa fdp
is not
.Dv NULL ,
the file descriptor will be written to it.
If the stream does not have an associated file descriptor,
.Fa fdp
will be set to -1.
This type of stream is created with functions such as
.Xr fmemopen 3 ,
.Xr funopen 3 ,
or
.Xr open_memstream 3 .
.Pp
The
.Fn fcloseall
function calls
.Fn fclose
on all open streams.
.Sh RETURN VALUES
.Fn fcloseall
does not return a value.
.Pp
Upon successful completion the
.Fn fclose
and
.Fn fdclose
functions return 0.
Otherwise,
.Dv EOF
is returned and the global variable
.Va errno
is set to indicate the error.
.Sh ERRORS
.Fn fdclose
fails if:
.Bl -tag -width Er
.It Bq Er EOPNOTSUPP
The stream does not have an associated file descriptor.
.El
.Pp
The
.Fn fclose
and
.Fn fdclose
functions may also fail and set
.Va errno
for any of the errors specified for
.Xr fflush 3 .
.Pp
The
.Fn fclose
function may also fail and set errno for any of the errors specified for
.Xr close 2 .
.Sh NOTES
The
.Fn fclose
and
.Fn fdclose
functions do not handle NULL arguments in the
.Fa stream
variable; this will result in a segmentation violation.
This is intentional.
It makes it easier to make sure programs written under
.Fx
are bug free.
This behaviour is an implementation detail, and programs should not
rely upon it.
.Sh SEE ALSO
.Xr close 2 ,
.Xr fflush 3 ,
.Xr fopen 3 ,
.Xr setbuf 3
.Sh STANDARDS
The
.Fn fclose
function
conforms to
.St -isoC .
.Sh HISTORY
The
.Fn fcloseall
function first appeared in
.Fx 7.0 .
.Pp
The
.Fn fdclose
function first appeared in
.Fx 11.0 .