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Diffstat (limited to 'lib/libc/gen/posix_spawn_file_actions_addopen.3')
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diff --git a/lib/libc/gen/posix_spawn_file_actions_addopen.3 b/lib/libc/gen/posix_spawn_file_actions_addopen.3 new file mode 100644 index 000000000000..80bc91454471 --- /dev/null +++ b/lib/libc/gen/posix_spawn_file_actions_addopen.3 @@ -0,0 +1,275 @@ +.\" Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org> +.\" All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" Portions of this text are reprinted and reproduced in electronic form +.\" from IEEE Std 1003.1, 2004 Edition, Standard for Information Technology -- +.\" Portable Operating System Interface (POSIX), The Open Group Base +.\" Specifications Issue 6, Copyright (C) 2001-2004 by the Institute of +.\" Electrical and Electronics Engineers, Inc and The Open Group. In the +.\" event of any discrepancy between this version and the original IEEE and +.\" The Open Group Standard, the original IEEE and The Open Group Standard is +.\" the referee document. The original Standard can be obtained online at +.\" http://www.opengroup.org/unix/online.html. +.\" +.Dd May 9, 2013 +.Dt POSIX_SPAWN_FILE_ACTIONS_ADDOPEN 3 +.Os +.Sh NAME +.Nm posix_spawn_file_actions_addopen , +.Nm posix_spawn_file_actions_adddup2 , +.Nm posix_spawn_file_actions_addclose , +.Nm posix_spawn_file_actions_addclosefrom_np , +.Nm posix_spawn_file_actions_addchdir_np , +.Nm posix_spawn_file_actions_addfchdir_np +.Nd "add open, dup2, close, closefrom, or chdir/fchdir actions to spawn file actions object" +.Sh LIBRARY +.Lb libc +.Sh SYNOPSIS +.In spawn.h +.Ft int +.Fo posix_spawn_file_actions_addopen +.Fa "posix_spawn_file_actions_t * file_actions" +.Fa "int fildes" +.Fa "const char *restrict path" +.Fa "int oflag" +.Fa "mode_t mode" +.Fc +.Ft int +.Fo posix_spawn_file_actions_adddup2 +.Fa "posix_spawn_file_actions_t * file_actions" +.Fa "int fildes" +.Fa "int newfildes" +.Fc +.Ft int +.Fo posix_spawn_file_actions_addclose +.Fa "posix_spawn_file_actions_t * file_actions" +.Fa "int fildes" +.Fc +.Ft int +.Fo posix_spawn_file_actions_addclosefrom_np +.Fa "posix_spawn_file_actions_t * file_actions" +.Fa "int from" +.Fc +.Ft int +.Fo posix_spawn_file_actions_addchdir_np +.Fa "posix_spawn_file_actions_t *restrict file_actions" +.Fa "const char *restrict path" +.Fc +.Ft int +.Fo posix_spawn_file_actions_addfchdir_np +.Fa "posix_spawn_file_actions_t * file_actions" +.Fa "int fildes" +.Fc +.Sh DESCRIPTION +These functions add an open, dup2 or close action to a spawn +file actions object. +.Pp +A spawn file actions object is of type +.Vt posix_spawn_file_actions_t +(defined in +.In spawn.h ) +and is used to specify a series of actions to be performed by a +.Fn posix_spawn +or +.Fn posix_spawnp +operation in order to arrive at the set of open file descriptors for the +child process given the set of open file descriptors of the parent. +.Pp +A spawn file actions object, when passed to +.Fn posix_spawn +or +.Fn posix_spawnp , +specify how the set of open file descriptors in the calling +process is transformed into a set of potentially open file descriptors +for the spawned process. +This transformation is as if the specified sequence of actions was +performed exactly once, in the context of the spawned process (prior to +execution of the new process image), in the order in which the actions +were added to the object; additionally, when the new process image is +executed, any file descriptor (from this new set) which has its +.Dv FD_CLOEXEC +flag set is closed (see +.Fn posix_spawn ) . +.Pp +The +.Fn posix_spawn_file_actions_addopen +function adds an open action to the object referenced by +.Fa file_actions +that causes the file named by +.Fa path +to be opened (as if +.Bd -literal -offset indent +open(path, oflag, mode) +.Ed +.Pp +had been called, and the returned file descriptor, if not +.Fa fildes , +had been changed to +.Fa fildes ) +when a new process is spawned using this file actions object. +If +.Fa fildes +was already an open file descriptor, it is closed before the new +file is opened. +.Pp +The string described by +.Fa path +is copied by the +.Fn posix_spawn_file_actions_addopen +function. +.Pp +The +.Fn posix_spawn_file_actions_adddup2 +function adds a dup2 action to the object referenced by +.Fa file_actions +that causes the file descriptor +.Fa fildes +to be duplicated as +.Fa newfildes +(as if +.Bd -literal -offset indent +dup2(fildes, newfildes) +.Ed +.Pp +had been called) when a new process is spawned using this file actions object, +except that the +.Dv FD_CLOEXEC +flag for +.Fa newfildes +is cleared even if +.Fa fildes +is equal to +.Fa newfildes . +The difference from +.Fn dup2 +is useful for passing a particular file descriptor +to a particular child process. +.Pp +The +.Fn posix_spawn_file_actions_addclose +function adds a close action to the object referenced by +.Fa file_actions +that causes the file descriptor +.Fa fildes +to be closed (as if +.Bd -literal -offset indent +close(fildes) +.Ed +.Pp +had been called) when a new process is spawned using this file actions +object. +.Pp +The +.Fn posix_spawn_file_actions_addclosefrom_np +function adds a close action to close all file descriptors numerically +equal or greater then the argument +.Fa from . +For each open file descriptor, logically the close action is performed, +and any possible errors encountered are ignored. +.Pp +The +.Fn posix_spawn_file_actions_addchdir_np +and +.Fn posix_spawn_file_actions_addfchdir_np +functions add a change current directory action to the object +referenced by +.Fa file_actions +that affects actions (opens with relative path) performed after the operation, +in the order of insertion into the +.Fa file_actions +object. +It also sets the working directory for the spawned program. +The +.Fn posix_spawn_file_actions_addchdir_np +function takes the +.Fa path +to set as the working directory, while +.Fn posix_spawn_file_actions_addfchdir_np +takes the directory file descriptor. +.Sh RETURN VALUES +Upon successful completion, these functions return zero; +otherwise, an error number is returned to indicate the error. +.Sh ERRORS +These +functions fail if: +.Bl -tag -width Er +.It Bq Er EBADF +The value specified by +.Fa fildes +or +.Fa newfildes +is negative. +.It Bq Er ENOMEM +Insufficient memory exists to add to the spawn file actions object. +.El +.Sh SEE ALSO +.Xr close 2 , +.Xr dup2 2 , +.Xr open 2 , +.Xr posix_spawn 3 , +.Xr posix_spawn_file_actions_destroy 3 , +.Xr posix_spawn_file_actions_init 3 , +.Xr posix_spawnp 3 +.Sh STANDARDS +The +.Fn posix_spawn_file_actions_addopen , +.Fn posix_spawn_file_actions_adddup2 +and +.Fn posix_spawn_file_actions_addclose +functions conform to +.St -p1003.1-2001 , +with the exception of the behavior of +.Fn posix_spawn_file_actions_adddup2 +if +.Fa fildes +is equal to +.Fa newfildes +(clearing +.Dv FD_CLOEXEC ) . +A future update of the Standard is expected to require this behavior. +.Pp +The +.Fn posix_spawn_file_actions_addchdir_np , +.Fn posix_spawn_file_actions_addfchdir_np , +and +.Fn posix_spawn_file_actions_addclosefrom_np +functions are non-standard functions implemented after the similar +functionality provided by glibc. +.Sh HISTORY +The +.Fn posix_spawn_file_actions_addopen , +.Fn posix_spawn_file_actions_adddup2 +and +.Fn posix_spawn_file_actions_addclose +functions first appeared in +.Fx 8.0 . +The +.Fn posix_spawn_file_actions_addchdir_np , +.Fn posix_spawn_file_actions_addfchdir_np , +and +.Fn posix_spawn_file_actions_addclosefrom_np +functions first appeared in +.Fx 13.1 . +.Sh AUTHORS +.An \&Ed Schouten Aq Mt ed@FreeBSD.org |