posix_spawn_file_actions_adddup2(3) - NetBSD Manual Pages

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POSIX_SPAWN_FILE_ACT... NetBSD Library Functions ManualPOSIX_SPAWN_FILE_ACT...


NAME

     posix_spawn_file_actions_addopen, posix_spawn_file_actions_adddup2,
     posix_spawn_file_actions_addclose -- add open, dup2 or close action to
     spawn file actions object


LIBRARY

     Standard C Library (libc, -lc)


SYNOPSIS

     #include <spawn.h>

     int
     posix_spawn_file_actions_addopen(posix_spawn_file_actions_t * file_actions,
         int fildes, const char *restrict path, int oflag, mode_t mode);

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

     int
     posix_spawn_file_actions_addclose(posix_spawn_file_actions_t * file_actions,
         int fildes);


DESCRIPTION

     These functions add an open, dup2 or close action to a spawn file actions
     object.

     A spawn file actions object is of type posix_spawn_file_actions_t
     (defined in <spawn.h>) and is used to specify a series of actions to be
     performed by a posix_spawn() or posix_spawnp() operation in order to
     arrive at the set of open file descriptors for the child process given
     the set of open file descriptors of the parent.

     A spawn file actions object, when passed to posix_spawn() or
     posix_spawnp(), specify how the set of open file descriptors in the call-
     ing process is transformed into a set of potentially open file descrip-
     tors for the spawned process.  This transformation is as if the specified
     sequence of actions was performed exactly once, in the context of the
     spawned process (prior to execution of the new process image), in the
     order in which the actions were added to the object; additionally, when
     the new process image is executed, any file descriptor (from this new
     set) which has its FD_CLOEXEC flag set is closed (see posix_spawn()).

     The posix_spawn_file_actions_addopen() function adds an open action to
     the object referenced by file_actions that causes the file named by path
     to be opened (as if

           open(path, oflag, mode)

     had been called, and the returned file descriptor, if not fildes, had
     been changed to fildes) when a new process is spawned using this file
     actions object.  If fildes was already an open file descriptor, it is
     closed before the new file is opened.

     The string described by path is copied by the
     posix_spawn_file_actions_addopen() function.

     The posix_spawn_file_actions_adddup2() function adds a dup2 action to the
     object referenced by file_actions that causes the file descriptor fildes
     to be duplicated as newfildes (as if

           dup2(fildes, newfildes)

     had been called) when a new process is spawned using this file actions
     object.

     The posix_spawn_file_actions_addclose() function adds a close action to
     the object referenced by file_actions that causes the file descriptor
     fildes to be closed (as if

           close(fildes)

     had been called) when a new process is spawned using this file actions
     object.


RETURN VALUES

     Upon successful completion, these functions return zero; otherwise, an
     error number is returned to indicate the error.


ERRORS

     These functions fail if:

     [EBADF]            The value specified by fildes or newfildes is nega-
                        tive.

     [EINVAL]           The value specified by file_actions is invalid.

     [ENOMEM]           Insufficient memory exists to add to the spawn file
                        actions object.


SEE ALSO

     close(2), dup2(2), open(2), posix_spawn(3),
     posix_spawn_file_actions_destroy(3), posix_spawn_file_actions_init(3),
     posix_spawnp(3)


STANDARDS

     The posix_spawn_file_actions_addopen(),
     posix_spawn_file_actions_adddup2() and
     posix_spawn_file_actions_addclose() functions conform to IEEE Std
     1003.1-2001 (``POSIX.1'').


HISTORY

     The posix_spawn_file_actions_addopen(),
     posix_spawn_file_actions_adddup2() and
     posix_spawn_file_actions_addclose() functions first appeared in
     FreeBSD 8.0 and imported for NetBSD 6.0.


AUTHORS

     Ed Schouten <ed@FreeBSD.org>

NetBSD 10.1                    February 2, 2014                    NetBSD 10.1