mirror of
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826509a3c3
- Use a typical tagged list for the open flags instead of a literal block. This permits using markup in the flag descriptions. Also, drop the offset to avoid indenting the entire list. - Note that O_RESOLVE_BENEATH only applies to openat(2) - Use a clearer description of O_CLOEXEC (what it means, not the internal flag it sets) - Note that exactly one permission flag is required. - Split up a paragraph on various flags so that each flag gets its own paragraph. Some flags already had their own paragraph, so this is more consistent. It also makes it clearer which flag a sentence is talking about when a flag has more than one sentence. - Appease some errors from igor and man2ps - In the discussion about a returned directory descriptor opened with O_SEARCH, avoid the use of Fa fd since the descriptor in question is a return value and not an argument to open or openat. - Various and sundry markup and language tweaks Reviewed by: kib, emaste Differential Revision: https://reviews.freebsd.org/D48253
773 lines
19 KiB
Groff
773 lines
19 KiB
Groff
.\" Copyright (c) 1980, 1991, 1993
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.\" The Regents of the University of California. All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 3. Neither the name of the University nor the names of its contributors
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.Dd January 3, 2025
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.Dt OPEN 2
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.Os
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.Sh NAME
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.Nm open , openat
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.Nd open or create a file for reading, writing or executing
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.Sh LIBRARY
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.Lb libc
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.Sh SYNOPSIS
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.In fcntl.h
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.Ft int
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.Fn open "const char *path" "int flags" "..."
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.Ft int
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.Fn openat "int fd" "const char *path" "int flags" "..."
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.Sh DESCRIPTION
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The file name specified by
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.Fa path
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is opened
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for either execution or reading and/or writing as specified by the
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argument
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.Fa flags
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and the file descriptor returned to the calling process.
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The
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.Fa flags
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argument may indicate the file is to be
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created if it does not exist (by specifying the
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.Dv O_CREAT
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flag).
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In this case
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.Fn open
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and
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.Fn openat
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require an additional argument
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.Fa "mode_t mode" ,
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and the file is created with mode
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.Fa mode
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as described in
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.Xr chmod 2
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and modified by the process' umask value (see
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.Xr umask 2 ) .
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.Pp
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The
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.Fn openat
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function is equivalent to the
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.Fn open
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function except in the case where the
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.Fa path
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specifies a relative path.
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For
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.Fn openat
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and relative
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.Fa path ,
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the file to be opened is determined relative to the directory
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associated with the file descriptor
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.Fa fd
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instead of the current working directory.
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The
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.Fa flag
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parameter and the optional fourth parameter correspond exactly to
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the parameters of
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.Fn open .
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If
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.Fn openat
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is passed the special value
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.Dv AT_FDCWD
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in the
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.Fa fd
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parameter, the current working directory is used
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and the behavior is identical to a call to
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.Fn open .
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.Pp
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When
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.Fn openat
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is called with an absolute
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.Fa path ,
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it ignores the
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.Fa fd
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argument.
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.Pp
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In
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.Xr capsicum 4
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capability mode,
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.Fn open
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is not permitted.
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The
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.Fa path
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argument to
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.Fn openat
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must be strictly relative to a file descriptor
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.Fa fd ;
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that is,
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.Fa path
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must not be an absolute path and must not contain ".." components
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which cause the path resolution to escape the directory hierarchy
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starting at
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.Fa fd .
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Additionally, no symbolic link in
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.Fa path
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may target absolute path or contain escaping ".." components.
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.Fa fd
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must not be
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.Dv AT_FDCWD .
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.Pp
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If the
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.Dv vfs.lookup_cap_dotdot
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.Xr sysctl 3
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MIB is set to zero, ".." components in the paths,
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used in capability mode,
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are completely disabled.
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If the
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.Dv vfs.lookup_cap_dotdot_nonlocal
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MIB is set to zero, ".." is not allowed if found on non-local filesystem.
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.Pp
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The
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.Fa flags
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are formed by
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.Em or Ns 'ing
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the following values:
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.Pp
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.Bl -tag -width O_RESOLVE_BENEATH
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.It Dv O_RDONLY
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open for reading only
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.It Dv O_WRONLY
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open for writing only
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.It Dv O_RDWR
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open for reading and writing
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.It Dv O_EXEC
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open for execute only
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.It Dv O_SEARCH
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open for search only
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(an alias for
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.Dv O_EXEC
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typically used with
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.Dv O_DIRECTORY )
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.It Dv O_NONBLOCK
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do not block on open
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.It Dv O_APPEND
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set file pointer to the end of the file before each write
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.It Dv O_CREAT
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create file if it does not exist
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.It Dv O_TRUNC
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truncate size to 0
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.It Dv O_EXCL
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fail if
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.Dv O_CREAT
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is set and the file exists
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.It Dv O_SHLOCK
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atomically obtain a shared lock
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.It Dv O_EXLOCK
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atomically obtain an exclusive lock
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.It Dv O_DIRECT
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read and write directly from the backing store
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.It Dv O_FSYNC
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synchronous data and metadata writes
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.Pq historical synonym for Dv O_SYNC
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.It Dv O_SYNC
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synchronous data and metadata writes
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.It Dv O_DSYNC
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synchronous data writes
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.It Dv O_NOFOLLOW
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do not follow symlinks
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.It Dv O_NOCTTY
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ignored
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.It Dv O_TTY_INIT
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ignored
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.It Dv O_DIRECTORY
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error if file is not a directory
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.It Dv O_CLOEXEC
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automatically close file on
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.Xr execve 2
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.It Dv O_VERIFY
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verify the contents of the file with
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.Xr mac_veriexec 4
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.It Dv O_RESOLVE_BENEATH
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.Pq Xr openat 2 only
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path resolution must not cross the
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.Fa fd
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directory
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.It Dv O_PATH
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record only the target path in the opened descriptor
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.It Dv O_EMPTY_PATH
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.Pq Xr openat 2 only
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open file referenced by
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.Fa fd
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if path is empty
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.El
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.Pp
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Exactly one of the flags
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.Dv O_RDONLY ,
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.Dv O_WRONLY ,
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.Dv O_RDWR ,
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or
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.Dv O_EXEC
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must be provided.
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.Pp
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Opening a file with
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.Dv O_APPEND
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set causes each write on the resulting file descriptor
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to be appended to the end of the file.
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.Pp
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If
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.Dv O_TRUNC
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is specified and the
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file exists, the file is truncated to zero length.
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.Pp
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If
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.Dv O_EXCL
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is set with
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.Dv O_CREAT
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and the file already
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exists,
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.Fn open
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fails with
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.Er EEXIST .
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This may be used to
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implement a simple exclusive access locking mechanism.
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If
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.Dv O_EXCL
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is set and the last component of the pathname is
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a symbolic link,
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.Fn open
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will fail even if the symbolic
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link points to a non-existent name.
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.Pp
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If
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.Dv O_NONBLOCK
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is specified and the
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.Fn open
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system call would
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block for some reason (for example, waiting for
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carrier on a dialup line),
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.Fn open
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returns immediately.
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The descriptor remains in non-blocking mode for subsequent operations.
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.Pp
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If
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.Dv O_SYNC
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is used in the mask, all writes will
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immediately and synchronously be written to disk.
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.Dv O_FSYNC
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is an historical synonym for
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.Dv O_SYNC .
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.Pp
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If
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.Dv O_DSYNC
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is used in the mask, all data and metadata required to read the data will be
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synchronously written to disk, but changes to metadata such as file access and
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modification timestamps may be written later.
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.Pp
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If
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.Dv O_NOFOLLOW
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is used in the mask and the target file passed to
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.Fn open
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is a symbolic link then the
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.Fn open
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will fail.
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.Pp
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When opening a file, a lock with
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.Xr flock 2
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semantics can be obtained by setting
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.Dv O_SHLOCK
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for a shared lock, or
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.Dv O_EXLOCK
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for an exclusive lock.
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If creating a file with
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.Dv O_CREAT ,
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the request for the lock will never fail
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(provided that the underlying file system supports locking).
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.Pp
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.Dv O_DIRECT
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may be used to minimize or eliminate the cache effects of reading and writing.
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The system will attempt to avoid caching the data you read or write.
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If it cannot avoid caching the data,
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it will minimize the impact the data has on the cache.
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Use of this flag can drastically reduce performance if not used with care.
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The semantics of this flag are filesystem dependent,
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and some filesystems may ignore it entirely.
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.Pp
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.Dv O_NOCTTY
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may be used to ensure the OS does not assign this file as the
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controlling terminal when it opens a tty device.
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This is the default on
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.Fx ,
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but is present for
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POSIX
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compatibility.
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The
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.Fn open
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system call will not assign controlling terminals on
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.Fx .
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.Pp
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.Dv O_TTY_INIT
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|
may be used to ensure the OS restores the terminal attributes when
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initially opening a TTY.
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This is the default on
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.Fx ,
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but is present for
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POSIX
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compatibility.
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The initial call to
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.Fn open
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on a TTY will always restore default terminal attributes on
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.Fx .
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.Pp
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|
.Dv O_DIRECTORY
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may be used to ensure the resulting file descriptor refers to a
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directory.
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|
This flag can be used to prevent applications with elevated privileges
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from opening files which are even unsafe to open with
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.Dv O_RDONLY ,
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such as device nodes.
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.Pp
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.Dv O_CLOEXEC
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may be used to set
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.Dv FD_CLOEXEC
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flag for the newly returned file descriptor.
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.Pp
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.Dv O_VERIFY
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may be used to indicate to the kernel that the contents of the file should
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be verified before allowing the open to proceed.
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The details of what
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.Dq verified
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means is implementation specific.
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The run-time linker (rtld) uses this flag to ensure shared objects have
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been verified before operating on them.
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.Pp
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.Dv O_RESOLVE_BENEATH
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|
returns
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.Er ENOTCAPABLE
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|
if any intermediate component of the specified relative path does not
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reside in the directory hierarchy beneath the starting directory.
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Absolute paths or even the temporal escape from beneath of the starting
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directory is not allowed.
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.Pp
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|
When a directory
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is opened with
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.Dv O_SEARCH ,
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execute permissions are checked at open time.
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The returned file descriptor
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may not be used for any read operations like
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.Xr getdirentries 2 .
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The primary use of this descriptor is as the lookup descriptor for the
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.Fn *at
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family of functions.
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If
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.Dv O_SEARCH
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was not requested at open time, then the
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.Fn *at
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functions use the current directory permissions for the directory referenced
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by the descriptor at the time of the
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.Fn *at
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call.
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.Pp
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.Dv O_PATH
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returns a file descriptor that can be used as a directory file descriptor for
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.Fn openat
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and other system calls taking a file descriptor argument, like
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.Xr fstatat 2
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and others.
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The other functionality of the returned file descriptor is limited to
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the following descriptor-level operations:
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.Pp
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.Bl -tag -width __acl_aclcheck_fd -offset indent -compact
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.It Xr fcntl 2
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|
but advisory locking is not allowed
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.It Xr dup 2
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.It Xr close 2
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.It Xr fstat 2
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.It Xr fexecve 2
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.It Dv SCM_RIGHTS
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can be passed over a
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.Xr unix 4
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socket using a
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.Dv SCM_RIGHTS
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message
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.It Xr kqueue 2
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|
only with
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.Dv EVFILT_VNODE
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|
.It Xr readlinkat 2
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|
.It Xr __acl_get_fd 2
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|
.It Xr __acl_aclcheck_fd 2
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|
.El
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|
.Pp
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|
Other operations like
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|
.Xr read 2 ,
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|
.Xr ftruncate 2 ,
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|
and any other that operate on file and not on file descriptor (except
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.Xr fstat 2 ),
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are not allowed.
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|
.Pp
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A file descriptor created with the
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.Dv O_PATH
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flag can be opened as a normal (operable) file descriptor by
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specifying it as the
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.Fa fd
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argument to
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.Fn openat
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with an empty
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.Fa path
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and the
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.Dv O_EMPTY_PATH
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flag.
|
|
Such an open behaves as if the current path of the file referenced by
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.Fa fd
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is passed, except that path walk permissions are not checked.
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See also the description of
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.Dv AT_EMPTY_PATH
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flag for
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.Xr fstatat 2
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|
and related syscalls.
|
|
.Pp
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If successful,
|
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.Fn open
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returns a non-negative integer, termed a file descriptor.
|
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It returns \-1 on failure.
|
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The file descriptor value returned is the lowest numbered descriptor
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currently not in use by the process.
|
|
The file pointer used to mark the current position within the
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file is set to the beginning of the file.
|
|
.Pp
|
|
If a sleeping open of a device node from
|
|
.Xr devfs 4
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is interrupted by a signal, the call always fails with
|
|
.Er EINTR ,
|
|
even if the
|
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.Dv SA_RESTART
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flag is set for the signal.
|
|
A sleeping open of a fifo (see
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|
.Xr mkfifo 2 )
|
|
is restarted as normal.
|
|
.Pp
|
|
When a new file is created, it is assigned the group of the directory
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|
which contains it.
|
|
.Pp
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|
Unless
|
|
.Dv O_CLOEXEC
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|
flag was specified,
|
|
the new descriptor is set to remain open across
|
|
.Xr execve 2
|
|
system calls; see
|
|
.Xr close 2 ,
|
|
.Xr fcntl 2
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|
and the description of the
|
|
.Dv O_CLOEXEC
|
|
flag.
|
|
.Pp
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|
The system imposes a limit on the number of file descriptors
|
|
open simultaneously by one process.
|
|
The
|
|
.Xr getdtablesize 2
|
|
system call returns the current system limit.
|
|
.Sh RETURN VALUES
|
|
If successful,
|
|
.Fn open
|
|
and
|
|
.Fn openat
|
|
return a non-negative integer, termed a file descriptor.
|
|
They return \-1 on failure, and set
|
|
.Va errno
|
|
to indicate the error.
|
|
.Sh ERRORS
|
|
The named file is opened unless:
|
|
.Bl -tag -width Er
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|
.It Bq Er ENOTDIR
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|
A component of the path prefix is not a directory.
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|
.It Bq Er ENAMETOOLONG
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|
A component of a pathname exceeded 255 characters,
|
|
or an entire path name exceeded 1023 characters.
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|
.It Bq Er ENOENT
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|
.Dv O_CREAT
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|
is not set and the named file does not exist.
|
|
.It Bq Er ENOENT
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|
A component of the path name that must exist does not exist.
|
|
.It Bq Er EACCES
|
|
Search permission is denied for a component of the path prefix.
|
|
.It Bq Er EACCES
|
|
The required permissions (for reading and/or writing)
|
|
are denied for the given flags.
|
|
.It Bq Er EACCES
|
|
.Dv O_TRUNC
|
|
is specified and write permission is denied.
|
|
.It Bq Er EACCES
|
|
.Dv O_CREAT
|
|
is specified,
|
|
the file does not exist,
|
|
and the directory in which it is to be created
|
|
does not permit writing.
|
|
.It Bq Er EPERM
|
|
.Dv O_CREAT
|
|
is specified, the file does not exist, and the directory in which it is to be
|
|
created has its immutable flag set, see the
|
|
.Xr chflags 2
|
|
manual page for more information.
|
|
.It Bq Er EPERM
|
|
The named file has its immutable flag set and the file is to be modified.
|
|
.It Bq Er EPERM
|
|
The named file has its append-only flag set, the file is to be modified, and
|
|
.Dv O_TRUNC
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|
is specified or
|
|
.Dv O_APPEND
|
|
is not specified.
|
|
.It Bq Er ELOOP
|
|
Too many symbolic links were encountered in translating the pathname.
|
|
.It Bq Er EISDIR
|
|
The named file is a directory, and the arguments specify
|
|
it is to be modified.
|
|
.It Bq Er EISDIR
|
|
The named file is a directory, and the flags specified
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|
.Dv O_CREAT
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|
without
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|
.Dv O_DIRECTORY .
|
|
.It Bq Er EROFS
|
|
The named file resides on a read-only file system,
|
|
and the file is to be modified.
|
|
.It Bq Er EROFS
|
|
.Dv O_CREAT
|
|
is specified and the named file would reside on a read-only file system.
|
|
.It Bq Er EMFILE
|
|
The process has already reached its limit for open file descriptors.
|
|
.It Bq Er ENFILE
|
|
The system file table is full.
|
|
.It Bq Er EMLINK
|
|
.Dv O_NOFOLLOW
|
|
was specified and the target is a symbolic link.
|
|
POSIX
|
|
specifies a different error for this case; see the note in
|
|
.Sx STANDARDS
|
|
below.
|
|
.It Bq Er ENXIO
|
|
The named file is a character special or block
|
|
special file, and the device associated with this special file
|
|
does not exist.
|
|
.It Bq Er ENXIO
|
|
.Dv O_NONBLOCK
|
|
is set, the named file is a fifo,
|
|
.Dv O_WRONLY
|
|
is set, and no process has the file open for reading.
|
|
.It Bq Er EINTR
|
|
The
|
|
.Fn open
|
|
operation was interrupted by a signal.
|
|
.It Bq Er EOPNOTSUPP
|
|
.Dv O_SHLOCK
|
|
or
|
|
.Dv O_EXLOCK
|
|
is specified but the underlying file system does not support locking.
|
|
.It Bq Er EOPNOTSUPP
|
|
The named file is a special file mounted through a file system that
|
|
does not support access to it (for example, NFS).
|
|
.It Bq Er EWOULDBLOCK
|
|
.Dv O_NONBLOCK
|
|
and one of
|
|
.Dv O_SHLOCK
|
|
or
|
|
.Dv O_EXLOCK
|
|
is specified and the file is locked.
|
|
.It Bq Er ENOSPC
|
|
.Dv O_CREAT
|
|
is specified,
|
|
the file does not exist,
|
|
and the directory in which the entry for the new file is being placed
|
|
cannot be extended because there is no space left on the file
|
|
system containing the directory.
|
|
.It Bq Er ENOSPC
|
|
.Dv O_CREAT
|
|
is specified,
|
|
the file does not exist,
|
|
and there are no free inodes on the file system on which the
|
|
file is being created.
|
|
.It Bq Er EDQUOT
|
|
.Dv O_CREAT
|
|
is specified,
|
|
the file does not exist,
|
|
and the directory in which the entry for the new file
|
|
is being placed cannot be extended because the
|
|
user's quota of disk blocks on the file system
|
|
containing the directory has been exhausted.
|
|
.It Bq Er EDQUOT
|
|
.Dv O_CREAT
|
|
is specified,
|
|
the file does not exist,
|
|
and the user's quota of inodes on the file system on
|
|
which the file is being created has been exhausted.
|
|
.It Bq Er EIO
|
|
An I/O error occurred while making the directory entry or
|
|
allocating the inode for
|
|
.Dv O_CREAT .
|
|
.It Bq Er EINTEGRITY
|
|
Corrupted data was detected while reading from the file system.
|
|
.It Bq Er ETXTBSY
|
|
The file is a pure procedure (shared text) file that is being
|
|
executed and the
|
|
.Fn open
|
|
system call requests write access.
|
|
.It Bq Er EFAULT
|
|
The
|
|
.Fa path
|
|
argument
|
|
points outside the process's allocated address space.
|
|
.It Bq Er EEXIST
|
|
.Dv O_CREAT
|
|
and
|
|
.Dv O_EXCL
|
|
were specified and the file exists.
|
|
.It Bq Er EOPNOTSUPP
|
|
An attempt was made to open a socket (not currently implemented).
|
|
.It Bq Er EINVAL
|
|
An attempt was made to open a descriptor with an illegal combination
|
|
of
|
|
.Dv O_RDONLY ,
|
|
.Dv O_WRONLY ,
|
|
or
|
|
.Dv O_RDWR ,
|
|
and
|
|
.Dv O_EXEC
|
|
or
|
|
.Dv O_SEARCH .
|
|
.It Bq Er EINVAL
|
|
.Dv O_CREAT
|
|
is specified,
|
|
and the last component of the
|
|
.Fa path
|
|
argument is invalid on the file system on which the file is being created.
|
|
.It Bq Er EBADF
|
|
The
|
|
.Fa path
|
|
argument does not specify an absolute path and the
|
|
.Fa fd
|
|
argument is
|
|
neither
|
|
.Dv AT_FDCWD
|
|
nor a valid file descriptor open for searching.
|
|
.It Bq Er ENOTDIR
|
|
The
|
|
.Fa path
|
|
argument is not an absolute path and
|
|
.Fa fd
|
|
is neither
|
|
.Dv AT_FDCWD
|
|
nor a file descriptor associated with a directory.
|
|
.It Bq Er ENOTDIR
|
|
.Dv O_DIRECTORY
|
|
is specified and the file is not a directory.
|
|
.It Bq Er ECAPMODE
|
|
.Dv AT_FDCWD
|
|
is specified and the process is in capability mode.
|
|
.It Bq Er ECAPMODE
|
|
.Fn open
|
|
was called and the process is in capability mode.
|
|
.It Bq Er ENOTCAPABLE
|
|
.Fa path
|
|
is an absolute path and the process is in capability mode.
|
|
.It Bq Er ENOTCAPABLE
|
|
.Fa path
|
|
is an absolute path and
|
|
.Dv O_RESOLVE_BENEATH
|
|
is specified.
|
|
.It Bq Er ENOTCAPABLE
|
|
.Fa path
|
|
contains a ".." component leading to a directory outside
|
|
of the directory hierarchy specified by
|
|
.Fa fd
|
|
and the process is in capability mode.
|
|
.It Bq Er ENOTCAPABLE
|
|
.Fa path
|
|
contains a ".." component leading to a directory outside
|
|
of the directory hierarchy specified by
|
|
.Fa fd
|
|
and
|
|
.Dv O_RESOLVE_BENEATH
|
|
is specified.
|
|
.It Bq Er ENOTCAPABLE
|
|
.Fa path
|
|
contains a ".." component, the
|
|
.Dv vfs.lookup_cap_dotdot
|
|
.Xr sysctl 3
|
|
is set, and the process is in capability mode.
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr chmod 2 ,
|
|
.Xr close 2 ,
|
|
.Xr dup 2 ,
|
|
.Xr fexecve 2 ,
|
|
.Xr fhopen 2 ,
|
|
.Xr getdtablesize 2 ,
|
|
.Xr getfh 2 ,
|
|
.Xr lgetfh 2 ,
|
|
.Xr lseek 2 ,
|
|
.Xr read 2 ,
|
|
.Xr umask 2 ,
|
|
.Xr write 2 ,
|
|
.Xr fopen 3 ,
|
|
.Xr capsicum 4
|
|
.Sh STANDARDS
|
|
These functions are specified by
|
|
.St -p1003.1-2008 .
|
|
.Pp
|
|
.Fx
|
|
sets
|
|
.Va errno
|
|
to
|
|
.Er EMLINK instead of
|
|
.Er ELOOP
|
|
as specified by
|
|
POSIX
|
|
when
|
|
.Dv O_NOFOLLOW
|
|
is set in flags and the final component of pathname is a symbolic link
|
|
to distinguish it from the case of too many symbolic link traversals
|
|
in one of its non-final components.
|
|
.Pp
|
|
The Open Group Extended API Set 2 specification, that introduced the
|
|
.Fn *at
|
|
API, required that the test for whether
|
|
.Fa fd
|
|
is searchable is based on whether
|
|
.Fa fd
|
|
is open for searching, not whether the underlying directory currently
|
|
permits searches.
|
|
The present implementation of the
|
|
.Fa openat
|
|
system call is believed to be compatible with
|
|
.\" .St -p1003.1-2017 ,
|
|
.\" XXX: This should be replaced in the future when an appropriate argument to
|
|
.\" the St macro is available: -p1003.1-2017
|
|
.No IEEE Std 1003.1-2008, 2017 Edition ("POSIX.1") ,
|
|
which specifies that behavior for
|
|
.Dv O_SEARCH ,
|
|
in the absence of the flag the implementation checks the current
|
|
permissions of a directory.
|
|
.Sh HISTORY
|
|
The
|
|
.Fn open
|
|
function appeared in
|
|
.At v1 .
|
|
The
|
|
.Fn openat
|
|
function was introduced in
|
|
.Fx 8.0 .
|
|
.Dv O_DSYNC
|
|
appeared in 13.0.
|
|
.Sh BUGS
|
|
The
|
|
.Fa mode
|
|
argument is variadic and may result in different calling conventions
|
|
than might otherwise be expected.
|