spawn.h(0P)

💖 PROLOG 💖

okay so bestie, before we even get into it: this manual page is part of the POSIX Programmer's Manual. that's the ✨official✨ spec energy. but heads up — the Linux implementation of this interface may differ (so if you're on Linux, go consult the corresponding Linux manual page for the real tea), or honestly the interface may not even be implemented on Linux at all. no cap. 🫶

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🌸 NAME 🌸

spawn.h — spawn (ADVANCED REALTIME)

like... the header. the vibe. the whole thing. it's giving advanced realtime, periodt. 👑

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✨ SYNOPSIS ✨

#include <spawn.h>

that's it. that's the whole synopsis. iconic. 💅

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🦋 DESCRIPTION 🦋

so the <spawn.h> header shall define the posix_spawnattr_t and posix_spawn_file_actions_t types — those are the ones you use when you're doing spawn operations. main character types, fr fr.

it shall also define the mode_t and pid_t types, exactly as described over in <sys/types.h>.

and it shall define the sigset_t type as described in <signal.h>. signals said "let me in" and the header said "okay bestie". 🌈

the tag sched_param shall be declared as naming an incomplete structure type — like, it's a mystery on purpose 😭 — and the contents of that struct are described in the <sched.h> header. so if you want the lore, go there.

now, the <spawn.h> header shall define the following symbolic constants, and these are for use as the flags that may be set in a posix_spawnattr_t object using the posix_spawnattr_setflags() function:

• POSIX_SPAWN_RESETIDS
• POSIX_SPAWN_SETPGROUP
• POSIX_SPAWN_SETSCHEDPARAM
• POSIX_SPAWN_SETSCHEDULER
• POSIX_SPAWN_SETSIGDEF
• POSIX_SPAWN_SETSIGMASK

six flags, six little icons, all of them slay. ✨

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🎀 the functions 🎀

the following shall be declared as functions and may also be defined as macros. function prototypes shall be provided. (yes, both. it's flexible like that. 💅)

int   posix_spawn(pid_t *restrict, const char *restrict,
          const posix_spawn_file_actions_t *,
          const posix_spawnattr_t *restrict, char *const [restrict],
          char *const [restrict]);
int   posix_spawn_file_actions_addclose(posix_spawn_file_actions_t *,
          int);
int   posix_spawn_file_actions_adddup2(posix_spawn_file_actions_t *,
          int, int);
int   posix_spawn_file_actions_addopen(posix_spawn_file_actions_t *restrict,
          int, const char *restrict, int, mode_t);
int   posix_spawn_file_actions_destroy(posix_spawn_file_actions_t *);
int   posix_spawn_file_actions_init(posix_spawn_file_actions_t *);
int   posix_spawnattr_destroy(posix_spawnattr_t *);
int   posix_spawnattr_getflags(const posix_spawnattr_t *restrict,
          short *restrict);
int   posix_spawnattr_getpgroup(const posix_spawnattr_t *restrict,
          pid_t *restrict);
int   posix_spawnattr_getschedparam(const posix_spawnattr_t *restrict,
          struct sched_param *restrict);
int   posix_spawnattr_getschedpolicy(const posix_spawnattr_t *restrict,
          int *restrict);
int   posix_spawnattr_getsigdefault(const posix_spawnattr_t *restrict,
          sigset_t *restrict);
int   posix_spawnattr_getsigmask(const posix_spawnattr_t *restrict,
          sigset_t *restrict);
int   posix_spawnattr_init(posix_spawnattr_t *);
int   posix_spawnattr_setflags(posix_spawnattr_t *, short);
int   posix_spawnattr_setpgroup(posix_spawnattr_t *, pid_t);
int   posix_spawnattr_setschedparam(posix_spawnattr_t *restrict,
          const struct sched_param *restrict);
int   posix_spawnattr_setschedpolicy(posix_spawnattr_t *, int);
int   posix_spawnattr_setsigdefault(posix_spawnattr_t *restrict,
          const sigset_t *restrict);
int   posix_spawnattr_setsigmask(posix_spawnattr_t *restrict,
          const sigset_t *restrict);
int   posix_spawnp(pid_t *restrict, const char *restrict,
          const posix_spawn_file_actions_t *,
          const posix_spawnattr_t *restrict,
          char *const [restrict], char *const [restrict]);

look at all those restrict qualifiers. they're all dressed up and they know it. 🫶

one more thing bestie — including the <spawn.h> header may make visible symbols that are defined in the <sched.h> and <signal.h> headers. so it can be a little bit of a group chat situation. you've been warned. 🙈

the following sections are informative. (translation: the spec parts are done, the rest is commentary.) 💜

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💅 APPLICATION USAGE 💅

None.

literally nothing. the void. and that's valid. 😌

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🧚 RATIONALE 🧚

None.

again — nothing. the reasoning is between the header and the compiler. iykyk. 💀

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⭐ FUTURE DIRECTIONS ⭐

None.

the future is bright and it contains no changes to this page. we love a stable queen. 👑

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🌈 SEE ALSO 🌈

• <sched.h>
• <semaphore.h>
• <signal.h>
• <sys_types.h>

and over in The System Interfaces volume of POSIX.1‐2017, these ones:

• posix_spawn()
• posix_spawn_file_actions_addclose()
• posix_spawn_file_actions_adddup2()
• posix_spawn_file_actions_destroy()
• posix_spawnattr_destroy()
• posix_spawnattr_getflags()
• posix_spawnattr_getpgroup()
• posix_spawnattr_getschedparam()
• posix_spawnattr_getschedpolicy()
• posix_spawnattr_getsigdefault()
• posix_spawnattr_getsigmask()

go read them, bestie. they're all connected. it's a whole cinematic universe. 🔥

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💜 COPYRIGHT 💜

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 .

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okay that's the whole thing, you made it to the end, so proud of you 🥹 this page is brought to you by IEEE/The Open Group, 2017, and it lives at spawn.h(0P). go spawn something iconic. bye bestie, mwah 💖✨🎀🦋