1 .\" Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org>
2 .\" All rights reserved.
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13 .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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25 .\" Portions of this text are reprinted and reproduced in electronic form
26 .\" from IEEE Std 1003.1, 2004 Edition, Standard for Information Technology --
27 .\" Portable Operating System Interface (POSIX), The Open Group Base
28 .\" Specifications Issue 6, Copyright (C) 2001-2004 by the Institute of
29 .\" Electrical and Electronics Engineers, Inc and The Open Group. In the
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31 .\" The Open Group Standard, the original IEEE and The Open Group Standard is
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33 .\" http://www.opengroup.org/unix/online.html.
38 .Dt POSIX_SPAWN_FILE_ACTIONS_ADDOPEN 3
41 .Nm posix_spawn_file_actions_addopen ,
42 .Nm posix_spawn_file_actions_adddup2 ,
43 .Nm posix_spawn_file_actions_addclose ,
44 .Nm posix_spawn_file_actions_addclosefrom_np ,
45 .Nm posix_spawn_file_actions_addchdir_np ,
46 .Nm posix_spawn_file_actions_addfchdir_np
47 .Nd "add open, dup2, close, closefrom, or chdir/fchdir actions to spawn file actions object"
53 .Fo posix_spawn_file_actions_addopen
54 .Fa "posix_spawn_file_actions_t * file_actions"
56 .Fa "const char *restrict path"
61 .Fo posix_spawn_file_actions_adddup2
62 .Fa "posix_spawn_file_actions_t * file_actions"
67 .Fo posix_spawn_file_actions_addclose
68 .Fa "posix_spawn_file_actions_t * file_actions"
72 .Fo posix_spawn_file_actions_addclosefrom_np
73 .Fa "posix_spawn_file_actions_t * file_actions"
77 .Fo posix_spawn_file_actions_addchdir_np
78 .Fa "posix_spawn_file_actions_t *restrict file_actions"
79 .Fa "const char *restrict path"
82 .Fo posix_spawn_file_actions_addfchdir_np
83 .Fa "posix_spawn_file_actions_t * file_actions"
87 These functions add an open, dup2 or close action to a spawn
90 A spawn file actions object is of type
91 .Vt posix_spawn_file_actions_t
94 and is used to specify a series of actions to be performed by a
98 operation in order to arrive at the set of open file descriptors for the
99 child process given the set of open file descriptors of the parent.
101 A spawn file actions object, when passed to
105 specify how the set of open file descriptors in the calling
106 process is transformed into a set of potentially open file descriptors
107 for the spawned process.
108 This transformation is as if the specified sequence of actions was
109 performed exactly once, in the context of the spawned process (prior to
110 execution of the new process image), in the order in which the actions
111 were added to the object; additionally, when the new process image is
112 executed, any file descriptor (from this new set) which has its
114 flag set is closed (see
118 .Fn posix_spawn_file_actions_addopen
119 function adds an open action to the object referenced by
121 that causes the file named by
124 .Bd -literal -offset indent
125 open(path, oflag, mode)
128 had been called, and the returned file descriptor, if not
132 when a new process is spawned using this file actions object.
135 was already an open file descriptor, it is closed before the new
138 The string described by
141 .Fn posix_spawn_file_actions_addopen
145 .Fn posix_spawn_file_actions_adddup2
146 function adds a dup2 action to the object referenced by
148 that causes the file descriptor
153 .Bd -literal -offset indent
154 dup2(fildes, newfildes)
157 had been called) when a new process is spawned using this file actions object,
168 is useful for passing a particular file descriptor
169 to a particular child process.
172 .Fn posix_spawn_file_actions_addclose
173 function adds a close action to the object referenced by
175 that causes the file descriptor
178 .Bd -literal -offset indent
182 had been called) when a new process is spawned using this file actions
186 .Fn posix_spawn_file_actions_addclosefrom_np
187 function adds a close action to close all file descriptors numerically
188 equal or greater then the argument
190 For each open file descriptor, logically the close action is performed,
191 and any possible errors encountered are ignored.
194 .Fn posix_spawn_file_actions_addchdir_np
196 .Fn posix_spawn_file_actions_addfchdir_np
197 functions add a change current directory action to the object
200 that affects actions (opens with relative path) performed after the operation,
201 in the order of insertion into the
204 It also sets the working directory for the spawned program.
206 .Fn posix_spawn_file_actions_addchdir_np
209 to set as the working directory, while
210 .Fn posix_spawn_file_actions_addfchdir_np
211 takes the directory file descriptor.
213 Upon successful completion, these functions return zero;
214 otherwise, an error number is returned to indicate the error.
220 The value specified by
226 Insufficient memory exists to add to the spawn file actions object.
233 .Xr posix_spawn_file_actions_destroy 3 ,
234 .Xr posix_spawn_file_actions_init 3 ,
238 .Fn posix_spawn_file_actions_addopen ,
239 .Fn posix_spawn_file_actions_adddup2
241 .Fn posix_spawn_file_actions_addclose
244 with the exception of the behavior of
245 .Fn posix_spawn_file_actions_adddup2
252 A future update of the Standard is expected to require this behavior.
255 .Fn posix_spawn_file_actions_addchdir_np ,
256 .Fn posix_spawn_file_actions_addfchdir_np ,
258 .Fn posix_spawn_file_actions_addclosefrom_np
259 functions are non-standard functions implemented after the similar
260 functionality provided by glibc.
263 .Fn posix_spawn_file_actions_addopen ,
264 .Fn posix_spawn_file_actions_adddup2
266 .Fn posix_spawn_file_actions_addclose
267 functions first appeared in
270 .Fn posix_spawn_file_actions_addchdir_np ,
271 .Fn posix_spawn_file_actions_addfchdir_np ,
273 .Fn posix_spawn_file_actions_addclosefrom_np
274 functions first appeared in
277 .An \&Ed Schouten Aq Mt ed@FreeBSD.org