mirror of https://github.com/mkerrisk/man-pages
123 lines
5.1 KiB
Plaintext
123 lines
5.1 KiB
Plaintext
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.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
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.TH "POSIX_SPAWNATTR_DESTROY" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
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.\" posix_spawnattr_destroy
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.SH NAME
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posix_spawnattr_destroy, posix_spawnattr_init \- destroy and initialize
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spawn attributes object (\fBADVANCED
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REALTIME\fP)
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.SH SYNOPSIS
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.LP
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\fB#include <spawn.h>
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.br
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.sp
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int posix_spawnattr_destroy(posix_spawnattr_t *\fP\fIattr\fP\fB);
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.br
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int posix_spawnattr_init(posix_spawnattr_t *\fP\fIattr\fP\fB); \fP
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\fB
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.br
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\fP
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.SH DESCRIPTION
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.LP
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The \fIposix_spawnattr_destroy\fP() function shall destroy a spawn
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attributes object. A destroyed \fIattr\fP attributes object
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can be reinitialized using \fIposix_spawnattr_init\fP(); the results
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of otherwise referencing the object after it has been
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destroyed are undefined. An implementation may cause \fIposix_spawnattr_destroy\fP()
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to set the object referenced by \fIattr\fP
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to an invalid value.
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.LP
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The \fIposix_spawnattr_init\fP() function shall initialize a spawn
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attributes object \fIattr\fP with the default value for all
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of the individual attributes used by the implementation. Results are
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undefined if \fIposix_spawnattr_init\fP() is called
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specifying an already initialized \fIattr\fP attributes object.
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.LP
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A spawn attributes object is of type \fBposix_spawnattr_t\fP (defined
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in \fI<spawn.h>\fP) and is used to specify the inheritance of process
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attributes across a spawn
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operation. IEEE\ Std\ 1003.1-2001 does not define comparison or assignment
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operators for the type
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\fBposix_spawnattr_t\fP.
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.LP
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Each implementation shall document the individual attributes it uses
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and their default values unless these values are defined by
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IEEE\ Std\ 1003.1-2001. Attributes not defined by IEEE\ Std\ 1003.1-2001,
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their default values, and the names of
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the associated functions to get and set those attribute values are
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implementation-defined.
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.LP
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The resulting spawn attributes object (possibly modified by setting
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individual attribute values), is used to modify the behavior
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of \fIposix_spawn\fP() or \fIposix_spawnp\fP(). After a spawn attributes
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object has been used to spawn a process by a
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call to a \fIposix_spawn\fP() or \fIposix_spawnp\fP(), any function
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affecting the attributes object (including destruction)
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shall not affect any process that has been spawned in this way.
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.SH RETURN VALUE
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.LP
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Upon successful completion, \fIposix_spawnattr_destroy\fP() and \fIposix_spawnattr_init\fP()
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shall return zero; otherwise, an
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error number shall be returned to indicate the error.
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.SH ERRORS
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.LP
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The \fIposix_spawnattr_init\fP() function shall fail if:
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.TP 7
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.B ENOMEM
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Insufficient memory exists to initialize the spawn attributes object.
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.sp
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.LP
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The \fIposix_spawnattr_destroy\fP() function may fail if:
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.TP 7
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.B EINVAL
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The value specified by attr is invalid.
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.sp
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.LP
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\fIThe following sections are informative.\fP
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.SH EXAMPLES
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.LP
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None.
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.SH APPLICATION USAGE
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.LP
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These functions are part of the Spawn option and need not be provided
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on all implementations.
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.SH RATIONALE
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.LP
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The original spawn interface proposed in IEEE\ Std\ 1003.1-2001 defined
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the attributes that specify the inheritance of
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process attributes across a spawn operation as a structure. In order
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to be able to separate optional individual attributes under
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their appropriate options (that is, the \fIspawn-schedparam\fP and
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\fIspawn-schedpolicy\fP attributes depending upon the Process
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Scheduling option), and also for extensibility and consistency with
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the newer POSIX interfaces, the attributes interface has been
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changed to an opaque data type. This interface now consists of the
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type \fBposix_spawnattr_t\fP, representing a spawn attributes
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object, together with associated functions to initialize or destroy
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the attributes object, and to set or get each individual
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attribute. Although the new object-oriented interface is more verbose
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than the original structure, it is simple to use, more
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extensible, and easy to implement.
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.SH FUTURE DIRECTIONS
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.LP
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None.
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.SH SEE ALSO
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.LP
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\fIposix_spawn\fP() , \fIposix_spawnattr_getsigdefault\fP() , \fIposix_spawnattr_getflags\fP()
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, \fIposix_spawnattr_getpgroup\fP() , \fIposix_spawnattr_getschedparam\fP()
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, \fIposix_spawnattr_getschedpolicy\fP() , \fIposix_spawnattr_getsigmask\fP()
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, \fIposix_spawnattr_setsigdefault\fP() , \fIposix_spawnattr_setflags\fP()
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, \fIposix_spawnattr_setpgroup\fP() , \fIposix_spawnattr_setsigmask\fP()
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, \fIposix_spawnattr_setschedpolicy\fP() , \fIposix_spawnattr_setschedparam\fP()
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, \fIposix_spawnp\fP() , the Base Definitions volume of IEEE\ Std\ 1003.1-2001,
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\fI<spawn.h>\fP
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.SH COPYRIGHT
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Portions of this text are reprinted and reproduced in electronic form
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from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
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-- Portable Operating System Interface (POSIX), The Open Group Base
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Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
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Electrical and Electronics Engineers, Inc and The Open Group. In the
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event of any discrepancy between this version and the original IEEE and
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The Open Group Standard, the original IEEE and The Open Group Standard
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is the referee document. The original Standard can be obtained online at
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http://www.opengroup.org/unix/online.html .
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