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.\" Hey Emacs! This file is -*- nroff -*- source.
.\"
.\" This manpage is Copyright (C) 2006, Michael Kerrisk
.\"
.\" Permission is granted to make and distribute verbatim copies of this
.\" manual provided the copyright notice and this permission notice are
.\" preserved on all copies.
.\"
.\" Permission is granted to copy and distribute modified versions of this
.\" manual under the conditions for verbatim copying, provided that the
.\" entire resulting derived work is distributed under the terms of a
.\" permission notice identical to this one.
.\"
.\" Since the Linux kernel and libraries are constantly changing, this
.\" manual page may be incorrect or out-of-date. The author(s) assume no
.\" responsibility for errors or omissions, or for damages resulting from
.\" the use of the information contained herein. The author(s) may not
.\" have taken the same level of care in the production of this manual,
.\" which is licensed free of charge, as they might when working
.\" professionally.
.\"
.\" Formatted or processed versions of this manual, if unaccompanied by
.\" the source, must acknowledge the copyright and authors of this work.
.\"
.\"
.TH FCHMODAT 2 2009-12-13 "Linux" "Linux Programmer's Manual"
.SH NAME
fchmodat \- change permissions of a file relative to a directory \
file descriptor
.SH SYNOPSIS
.nf
.B #include <fcntl.h> /* Definition of AT_* constants */
.B #include <sys/stat.h>
.sp
.BI "int fchmodat(int " dirfd ", const char *" pathname ", mode_t " \
mode ", int " flags );
.fi
.sp
.in -4n
Feature Test Macro Requirements for glibc (see
.BR feature_test_macros (7)):
.in
.sp
.BR fchmodat ():
.PD 0
.ad l
.RS 4
.TP 4
Since glibc 2.10:
_XOPEN_SOURCE\ >=\ 700 || _POSIX_C_SOURCE\ >=\ 200809L
.TP
Before glibc 2.10:
_ATFILE_SOURCE
.RE
.ad
.PD
.SH DESCRIPTION
The
.BR fchmodat ()
system call operates in exactly the same way as
.BR chmod (2),
except for the differences described in this manual page.
If the pathname given in
.I pathname
is relative, then it is interpreted relative to the directory
referred to by the file descriptor
.I dirfd
(rather than relative to the current working directory of
the calling process, as is done by
.BR chmod (2)
for a relative pathname).
If
.I pathname
is relative and
.I dirfd
is the special value
.BR AT_FDCWD ,
then
.I pathname
is interpreted relative to the current working
directory of the calling process (like
.BR chmod (2)).
If
.I pathname
is absolute, then
.I dirfd
is ignored.
.I flags
can either be 0, or include the following flag:
.TP
.B AT_SYMLINK_NOFOLLOW
If
.I pathname
is a symbolic link, do not dereference it:
instead operate on the link itself.
This flag is not currently implemented.
.SH "RETURN VALUE"
On success,
.BR fchmodat ()
returns 0.
On error, \-1 is returned and
.I errno
is set to indicate the error.
.SH ERRORS
The same errors that occur for
.BR chmod (2)
can also occur for
.BR fchmodat ().
The following additional errors can occur for
.BR fchmodat ():
.TP
.B EBADF
.I dirfd
is not a valid file descriptor.
.TP
.B EINVAL
Invalid flag specified in
.IR flags .
.TP
.B ENOTDIR
.I pathname
is relative and
.I dirfd
is a file descriptor referring to a file other than a directory.
.TP
.B ENOTSUP
.I flags
specified
.BR AT_SYMLINK_NOFOLLOW ,
which is not supported.
.SH VERSIONS
.BR fchmodat ()
was added to Linux in kernel 2.6.16.
.SH "CONFORMING TO"
POSIX.1-2008.
.SH NOTES
See
.BR openat (2)
for an explanation of the need for
.BR fchmodat ().
.SH "SEE ALSO"
.BR chmod (2),
.BR openat (2),
.BR path_resolution (7),
.BR symlink (7)
.SH COLOPHON
This page is part of release 3.27 of the Linux
.I man-pages
project.
A description of the project,
and information about reporting bugs,
can be found at
http://www.kernel.org/doc/man-pages/.
|
