POSIX_S..._DESTROY(3POSIX)

πŸ’… POSIX_S..._DESTROY β€” the POSIX Programmer's Manual, bestie edition ✨

okay so quick heads up before we even start: this page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (so like, go check the corresponding Linux manual page for the deets on Linux behavior), or honestly the interface might not even be implemented on Linux at all. πŸ™ˆ


🌸 PROLOG 🌸

This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ β€” consult the corresponding Linux manual page for details of Linux behavior β€” or the interface may not be implemented on Linux. That's it, that's the prolog, moving on bestie. 🫢


πŸ‘‘ NAME πŸ‘‘

posix_spawnattr_destroy, posix_spawnattr_init β€” destroy and initialize spawn attributes object (ADVANCED REALTIME)


✨ SYNOPSIS ✨

#include <spawn.h>

int posix_spawnattr_destroy(posix_spawnattr_t *attr);
int posix_spawnattr_init(posix_spawnattr_t *attr);

πŸ¦‹ DESCRIPTION πŸ¦‹

So posix_spawnattr_destroy() shall destroy a spawn attributes object. And here's the tea: a destroyed attr attributes object can be reinitialized using posix_spawnattr_init(), but the results of otherwise referencing the object after it has been destroyed are undefined. 😭 An implementation may cause posix_spawnattr_destroy() to set the object referenced by attr to an invalid value. So like, don't touch it after, fr fr.

Meanwhile posix_spawnattr_init() shall initialize a spawn attributes object attr with the default value for all of the individual attributes used by the implementation. And listen β€” results are undefined if posix_spawnattr_init() is called specifying an already initialized attr attributes object. So don't double-init, that's not the vibe. πŸ’€

A spawn attributes object is of type posix_spawnattr_t (defined in <spawn.h>) and is used to specify the inheritance of process attributes across a spawn operation. POSIX.1‐2008 does not define comparison or assignment operators for the type posix_spawnattr_t. No = for you, bestie. πŸ™…

Each implementation shall document the individual attributes it uses and their default values, unless these values are defined by POSIX.1‐2008. Attributes not defined by POSIX.1‐2008, their default values, and the names of the associated functions to get and set those attribute values are implementation-defined. So it's giving "read your implementation's docs," iykyk. πŸ“–

The resulting spawn attributes object (possibly modified by setting individual attribute values) is used to modify the behavior of posix_spawn() or posix_spawnp(). After a spawn attributes object has been used to spawn a process by a call to a posix_spawn() or posix_spawnp(), any function affecting the attributes object (including destruction) shall not affect any process that has been spawned in this way. Periodt β€” the spawned process is independent, she's her own main character. πŸ’…


πŸ”₯ RETURN VALUE πŸ”₯

Upon successful completion, posix_spawnattr_destroy() and posix_spawnattr_init() shall return zero. Otherwise, an error number shall be returned to indicate the error. Zero means slay, nonzero means we have a situation. ✨


πŸ’€ ERRORS πŸ’€

The posix_spawnattr_init() function shall fail if:

  • ENOMEM β€” Insufficient memory exists to initialize the spawn attributes object.

The posix_spawnattr_destroy() function may fail if:

  • EINVAL β€” The value specified by attr is invalid.
The following sections are informative. (So like, the drama is over, this is just lore now. πŸŽ€)

🌈 EXAMPLES 🌈

None. Literally none. There are no examples. That's the whole section. πŸ™ˆ


πŸ’œ APPLICATION USAGE πŸ’œ

These functions are part of the Spawn option and need not be provided on all implementations. So if you can't find them, it's not you, it's the implementation. 🫢


🧚 RATIONALE 🧚

okay so storytime: the original spawn interface proposed in POSIX.1‐2008 defined the attributes that specify the inheritance of process attributes across a spawn operation as a structure. But to be able to separate optional individual attributes under their appropriate options (that is, the spawn-schedparam and spawn-schedpolicy 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. Glow-up, honestly. πŸ’…

This interface now consists of the type posix_spawnattr_t, representing a spawn attributes object, together with associated functions to initialize or destroy the attributes object, and to set or get each individual attribute. And yeah β€” although the new object-oriented interface is more verbose than the original structure, it is simple to use, more extensible, and easy to implement. More words, better vibes. Iconic. ✨


⭐ FUTURE DIRECTIONS ⭐

None. Nothing coming. The future is quiet. πŸ¦‹


πŸŽ€ SEE ALSO πŸŽ€

  • posix_spawn()
  • posix_spawnattr_getsigdefault()
  • posix_spawnattr_getflags()
  • posix_spawnattr_getpgroup()
  • posix_spawnattr_getschedparam()
  • posix_spawnattr_getschedpolicy()
  • posix_spawnattr_getsigmask()

The Base Definitions volume of POSIX.1‐2017, <spawn.h>


Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 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.

Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html.


and that's the whole page, bestie β€” brought to you by IEEE/The Open Group, 2017 πŸ’– go forth and spawn responsibly ✨