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.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved 

.TH "POSIX_SPAWNATTR_DESTROY" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"

.\" posix_spawnattr_destroy 

.SH NAME

posix_spawnattr_destroy, posix_spawnattr_init \- destroy and initialize

spawn attributes object (\fBADVANCED

REALTIME\fP)

.SH SYNOPSIS

.LP

\fB#include <spawn.h>

.br

.sp

int posix_spawnattr_destroy(posix_spawnattr_t *\fP\fIattr\fP\fB);

.br

int posix_spawnattr_init(posix_spawnattr_t *\fP\fIattr\fP\fB); \fP

\fB

.br

\fP

.SH DESCRIPTION

.LP

The \fIposix_spawnattr_destroy\fP() function shall destroy a spawn

attributes object. A destroyed \fIattr\fP attributes object

can be reinitialized using \fIposix_spawnattr_init\fP(); the results

of otherwise referencing the object after it has been

destroyed are undefined. An implementation may cause \fIposix_spawnattr_destroy\fP()

to set the object referenced by \fIattr\fP

to an invalid value.

.LP

The \fIposix_spawnattr_init\fP() function shall initialize a spawn

attributes object \fIattr\fP with the default value for all

of the individual attributes used by the implementation. Results are

undefined if \fIposix_spawnattr_init\fP() is called

specifying an already initialized \fIattr\fP attributes object.

.LP

A spawn attributes object is of type \fBposix_spawnattr_t\fP (defined

in \fI<spawn.h>\fP) and is used to specify the inheritance of process

attributes across a spawn

operation. IEEE\ Std\ 1003.1-2001 does not define comparison or assignment

operators for the type

\fBposix_spawnattr_t\fP.

.LP

Each implementation shall document the individual attributes it uses

and their default values unless these values are defined by

IEEE\ Std\ 1003.1-2001. Attributes not defined by IEEE\ Std\ 1003.1-2001,

their default values, and the names of

the associated functions to get and set those attribute values are

implementation-defined.

.LP

The resulting spawn attributes object (possibly modified by setting

individual attribute values), is used to modify the behavior

of \fIposix_spawn\fP() or \fIposix_spawnp\fP(). After a spawn attributes

object has been used to spawn a process by a

call to a \fIposix_spawn\fP() or \fIposix_spawnp\fP(), any function

affecting the attributes object (including destruction)

shall not affect any process that has been spawned in this way.

.SH RETURN VALUE

.LP

Upon successful completion, \fIposix_spawnattr_destroy\fP() and \fIposix_spawnattr_init\fP()

shall return zero; otherwise, an

error number shall be returned to indicate the error.

.SH ERRORS

.LP

The \fIposix_spawnattr_init\fP() function shall fail if:

.TP 7

.B ENOMEM

Insufficient memory exists to initialize the spawn attributes object.

.sp

.LP

The \fIposix_spawnattr_destroy\fP() function may fail if:

.TP 7

.B EINVAL

The value specified by attr is invalid.

.sp

.LP

\fIThe following sections are informative.\fP

.SH EXAMPLES

.LP

None.

.SH APPLICATION USAGE

.LP

These functions are part of the Spawn option and need not be provided

on all implementations.

.SH RATIONALE

.LP

The original spawn interface proposed in IEEE\ Std\ 1003.1-2001 defined

the attributes that specify the inheritance of

process attributes across a spawn operation as a structure. In order

to be able to separate optional individual attributes under

their appropriate options (that is, the \fIspawn-schedparam\fP and

\fIspawn-schedpolicy\fP attributes depending upon the Process

Scheduling option), and also for extensibility and consistency with

the newer POSIX interfaces, the attributes interface has been

changed to an opaque data type. This interface now consists of the

type \fBposix_spawnattr_t\fP, representing a spawn attributes

object, together with associated functions to initialize or destroy

the attributes object, and to set or get each individual

attribute. Although the new object-oriented interface is more verbose

than the original structure, it is simple to use, more

extensible, and easy to implement.

.SH FUTURE DIRECTIONS

.LP

None.

.SH SEE ALSO

.LP

\fIposix_spawn\fP() , \fIposix_spawnattr_getsigdefault\fP() , \fIposix_spawnattr_getflags\fP()

, \fIposix_spawnattr_getpgroup\fP() , \fIposix_spawnattr_getschedparam\fP()

, \fIposix_spawnattr_getschedpolicy\fP() , \fIposix_spawnattr_getsigmask\fP()

, \fIposix_spawnattr_setsigdefault\fP() , \fIposix_spawnattr_setflags\fP()

, \fIposix_spawnattr_setpgroup\fP() , \fIposix_spawnattr_setsigmask\fP()

, \fIposix_spawnattr_setschedpolicy\fP() , \fIposix_spawnattr_setschedparam\fP()

, \fIposix_spawnp\fP() , the Base Definitions volume of IEEE\ Std\ 1003.1-2001,

\fI<spawn.h>\fP

.SH COPYRIGHT

Portions of this text are reprinted and reproduced in electronic form

from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology

-- Portable Operating System Interface (POSIX), The Open Group Base

Specifications Issue 6, Copyright (C) 2001-2003 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 .