POSIX_SPAWN_FILE_ACTIONS_ADDDUP2(3C) Standard C Library Functions POSIX_SPAWN_FILE_ACTIONS_ADDDUP2(3C)

posix_spawn_file_actions_adddup2add dup2 action to spawn file actions object

Standard C Library (libc, -lc)

#include <spawn.h>

int
posix_spawn_file_actions_adddup2(posix_spawn_file_actions_t *file_actions, int fildes, int newfildes);

The () function adds a dup2(3C) action to the object referenced by file_actions that causes the file descriptor fildes to be duplicated as newfildes (as if (fildes, newfildes) had been called) when a new process is spawned using this file actions object.

A spawn file actions object is as defined in posix_spawn_file_actions_addclose(3C).

Upon successful completion, the posix_spawn_file_actions_adddup2() function returns 0. Otherwise, an error number is returned to indicate the error.

The posix_spawn_file_actions_adddup2() function will fail if:

The value specified by fildes or newfildes is negative or greater than or equal to {OPEN_MAX}.
Insufficient memory exists to add to the spawn file actions object.

The posix_spawn_file_actions_adddup2() function may fail if:

The value specified by file_actions is invalid.

It is not considered an error for the fildes argument passed to posix_spawn_file_actions_adddup2() to specify a file descriptor for which the specified operation could not be performed at the time of the call. Any such error will be detected when the associated file actions object is later used during a posix_spawn(3C) or posix_spawnp(3C) operation.

dup2(3C), posix_spawn(3C), posix_spawn_file_actions_addclose(3C), posix_spawn_file_actions_destroy(3C), attributes(7), standards(7)

The posix_spawn_file_actions_adddup2() function conforms to IEEE Std 1003.1-2001 (“POSIX.1”).

July 4, 2026 OmniOS