mirror of https://github.com/mkerrisk/man-pages
chmod.2: Merge text from fchmodat(2)
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This commit is contained in:
Michael Kerrisk
parent
c331132477
commit
92f114db82
126
man2/chmod.2
126
man2/chmod.2
|
|
@ -1,4 +1,5 @@
|
|||
.\" Copyright (c) 1992 Drew Eckhardt (drew@cs.colorado.edu), March 28, 1992
|
||||
.\" and Copyright (C) 2006, 2014 Michael Kerrisk
|
||||
.\"
|
||||
.\" %%%LICENSE_START(VERBATIM)
|
||||
.\" Permission is granted to make and distribute verbatim copies of this
|
||||
|
|
@ -28,16 +29,24 @@
|
|||
.\" <michael@cantor.informatik.rwth-aachen.de>: NFS details
|
||||
.\" Modified 2004-06-23 by Michael Kerrisk <mtk.manpages@gmail.com>
|
||||
.\"
|
||||
.TH CHMOD 2 2010-09-26 "Linux" "Linux Programmer's Manual"
|
||||
.TH CHMOD 2 2014-02-21 "Linux" "Linux Programmer's Manual"
|
||||
.SH NAME
|
||||
chmod, fchmod \- change permissions of a file
|
||||
chmod, fchmod, fchmodat \- change permissions of a file
|
||||
.SH SYNOPSIS
|
||||
.nf
|
||||
.B #include <sys/stat.h>
|
||||
.sp
|
||||
.BI "int chmod(const char *" path ", mode_t " mode );
|
||||
.br
|
||||
.BI "int fchmod(int " fd ", mode_t " mode );
|
||||
.sp
|
||||
.BR "#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)):
|
||||
|
|
@ -54,6 +63,20 @@ _XOPEN_SOURCE\ &&\ _XOPEN_SOURCE_EXTENDED
|
|||
|| /* Since glibc 2.12: */ _POSIX_C_SOURCE\ >=\ 200809L
|
||||
.RE
|
||||
.PD
|
||||
.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
|
||||
.ad
|
||||
.SH DESCRIPTION
|
||||
These system calls change the permissions of a file.
|
||||
|
|
@ -150,6 +173,52 @@ already open files, because the access control is done on the server, but
|
|||
open files are maintained by the client.
|
||||
Widening the permissions may be
|
||||
delayed for other clients if attribute caching is enabled on them.
|
||||
.\"
|
||||
.\"
|
||||
.SS fchmodat()
|
||||
The
|
||||
.BR fchmodat ()
|
||||
system call operates in exactly the same way as
|
||||
.BR chmod (2),
|
||||
except for the differences described here.
|
||||
|
||||
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, zero is returned.
|
||||
On error, \-1 is returned, and
|
||||
|
|
@ -216,12 +285,61 @@ See above.
|
|||
.TP
|
||||
.B EROFS
|
||||
See above.
|
||||
.PP
|
||||
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;
|
||||
library support was added to glibc in version 2.4.
|
||||
.SH CONFORMING TO
|
||||
.BR chmod (),
|
||||
.BR fchmod ():
|
||||
4.4BSD, SVr4, POSIX.1-2001.
|
||||
|
||||
.BR fchmodat ():
|
||||
POSIX.1-2008.
|
||||
.SH NOTES
|
||||
See
|
||||
.BR openat (2)
|
||||
for an explanation of the need for
|
||||
.BR fchmodat ().
|
||||
|
||||
The GNU C library wrapper function implements the POSIX-specified
|
||||
interface described in this page.
|
||||
This interface differs from the underlying Linux system call, which does
|
||||
.I not
|
||||
have a
|
||||
.I flags
|
||||
argument.
|
||||
.SH SEE ALSO
|
||||
.BR chown (2),
|
||||
.BR execve (2),
|
||||
.BR fchmodat (2),
|
||||
.BR open (2),
|
||||
.BR stat (2),
|
||||
.BR path_resolution (7)
|
||||
.BR path_resolution (7),
|
||||
.BR symlink (7)
|
||||
|
|
|
|||
Loading…
Reference in New Issue