X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/2d21ac55c334faf3a56e5634905ed6987fc787d4..fe8ab488e9161c46dd9885d58fc52996dc0249ff:/bsd/man/man2/fcntl.2 diff --git a/bsd/man/man2/fcntl.2 b/bsd/man/man2/fcntl.2 index d228a17c1..ce2daefe5 100644 --- a/bsd/man/man2/fcntl.2 +++ b/bsd/man/man2/fcntl.2 @@ -1,3 +1,26 @@ +.\" +.\" Copyright (c) 2011 Apple Inc. All rights reserved. +.\" +.\" @APPLE_LICENSE_HEADER_START@ +.\" +.\" This file contains Original Code and/or Modifications of Original Code +.\" as defined in and that are subject to the Apple Public Source License +.\" Version 2.0 (the 'License'). You may not use this file except in +.\" compliance with the License. Please obtain a copy of the License at +.\" http://www.opensource.apple.com/apsl/ and read it before using this +.\" file. +.\" +.\" The Original Code and all software distributed under the License are +.\" distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER +.\" EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, +.\" INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, +.\" FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. +.\" Please see the License for the specific language governing rights and +.\" limitations under the License. +.\" +.\" @APPLE_LICENSE_HEADER_END@ +.\" +.\" .\" $NetBSD: fcntl.2,v 1.6 1995/02/27 12:32:29 cgd Exp $ .\" .\" Copyright (c) 1983, 1993 @@ -33,7 +56,7 @@ .\" .\" @(#)fcntl.2 8.2 (Berkeley) 1/12/94 .\" -.Dd January 12, 1994 +.Dd February 17, 2011 .Dt FCNTL 2 .Os BSD 4.2 .Sh NAME @@ -75,26 +98,24 @@ Same file status flags (i.e., both file descriptors share the same file status flags). .It The close-on-exec flag associated with the new file descriptor -is set to remain open across +is cleared so that the descriptor remains open across an .Xr execv 2 -system calls. +system call. .El +.It Dv F_DUPFD_CLOEXEC +Like +.Dv F_DUPFD , +except that the close-on-exec flag associated with the new file descriptor +is set. .It Dv F_GETFD -Get the close-on-exec flag associated with the file descriptor -.Fa fildes . -If the low-order bit of the returned value is 0, -the file will remain open across -.Fn exec , -otherwise the file will be closed upon execution of -.Fn exec +Get the flags associated with the file descriptor +.Fa fildes , +as described below .Fa ( arg is ignored). .It Dv F_SETFD -Set the close-on-exec flag associated with -.Fa fildes -to the low order bit of -.Fa arg -(0 or 1 as above). +Set the file descriptor flags to +.Fa arg . .It Dv F_GETFL Get descriptor status flags, as described below .Fa ( arg @@ -131,7 +152,9 @@ The argument must be a buffer of size .Sy MAXPATHLEN or greater. .It Dv F_PREALLOCATE -Preallocate file storage space. +Preallocate file storage space. Note: upon success, +the space that is allocated can be the same size or +larger than the space requested. .It Dv F_SETSIZE Truncate a file without zeroing space. The calling process must have root privileges. @@ -161,7 +184,13 @@ turns data caching on. Get disk device information. Currently this only includes the disk device address that corresponds -to the current file offset. +to the current file offset. Note that if the +file offset is not backed by physical blocks +we can return -1 as the offset. This is subject +to change. +.It Dv F_LOG2PHYS_EXT +Variant of F_LOG2PHYS that uses the passed in +file offset and length. .It Dv F_FULLFSYNC Does the same thing as .Xr fsync 2 @@ -175,6 +204,43 @@ and Universal Disk Format (UDF) file systems. The operation may take quite a while to complete. Certain FireWire drives have also been known to ignore the request to flush their buffered data. +.It Dv F_SETNOSIGPIPE +Determines whether a +.Dv SIGPIPE +signal will be generated when a write fails on a pipe or socket for +which there is no reader. If +.Fa arg +is non-zero, +.Dv SIGPIPE +generation is disabled for descriptor +.Fa fildes , +while an +.Fa arg +of zero enables it (the default). +.It Dv F_GETNOSIGPIPE +Returns whether a +.Dv SIGPIPE +signal will be generated when a write fails on a pipe or socket +for which there is no reader. The semantics of the return value +match those of the +.Fa arg +of +.Dv F_SETNOSIGPIPE . +.El +.Pp +The flags for the +.Dv F_GETFD +and +.Dv F_SETFD +commands are as follows: +.Bl -tag -width FD_CLOEXECX -offset indent +.It Dv FD_CLOEXEC +Close-on-exec; the given file descriptor will be automatically +closed in the successor process image when one of the +.Xr execv 2 +or +.Xr posix_spawn 2 +family of system calls is invoked. .El .Pp The flags for the @@ -253,7 +319,7 @@ as well as remove either type of lock If a shared or exclusive lock cannot be set, .Nm fcntl returns immediately with -.Er EACCES . +.Er EAGAIN . .It Dv F_SETLKW This command is the same as .Dv F_SETLK @@ -451,15 +517,43 @@ commands operate on the following structure. .Pp The .Dv F_LOG2PHYS -command operates on the following structure. +command operates on the following structure: +.ne 7v +.Bd -literal + struct log2phys { + u_int32_t l2p_flags; /* unused so far */ + off_t l2p_contigbytes; /* unused so far */ + off_t l2p_devoffset; /* bytes into device */ + }; +.Ed +.Pp +The +.Dv F_LOG2PHYS_EXT +command operates on the same structure as F_LOG2PHYS but treats it as an in/out: .ne 7v .Bd -literal struct log2phys { - u_int32_t l2p_flags; /* unused so far */ - off_t l2p_contigbytes; /* unused so far */ - off_t l2p_devoffset; /* bytes into device */ + u_int32_t l2p_flags; /* unused so far */ + off_t l2p_contigbytes; /* IN: number of bytes to be queried; + OUT: number of contiguous bytes allocated at this position */ + off_t l2p_devoffset; /* IN: bytes into file; + OUT: bytes into device */ }; .Ed +.Pp +If +.Fa fildes +is a socket, then the +.Dv F_SETNOSIGPIPE +and +.Dv F_GETNOSIGPIPE +commands are directly analogous, and fully interoperate with the +.Dv SO_NOSIGPIPE +option of +.Xr setsockopt 2 +and +.Xr getsockopt 2 +respectively. .Sh RETURN VALUES Upon successful completion, the value returned depends on .Fa cmd @@ -486,7 +580,7 @@ The system call will fail if: .Bl -tag -width Er .\" ========== -.It Bq Er EACCES +.It Bq Er EAGAIN The argument .Fa cmd is @@ -502,7 +596,7 @@ exclusive-locked by another process; or the type is an exclusive lock and some portion of the segment of a file to be locked is already shared-locked or exclusive-locked by another process. -.Pp +.It Bq Er EACCESS The argument .Fa cmd is either @@ -554,6 +648,8 @@ The argument .Fa cmd is .Dv F_LOG2PHYS +or +.Dv F_LOG2PHYS_EXT and .Fa fildes is not a valid file descriptor open for reading. @@ -671,6 +767,9 @@ the process ID given as argument is not in use. .Xr flock 2 , .Xr getdtablesize 2 , .Xr open 2 , +.Xr pipe 2 , +.Xr socket 2 , +.Xr setsockopt 2 , .Xr sigaction 3 .Sh HISTORY The