POSIX_SPAWN_PIPE_NP(3C) Standard C Library Functions POSIX_SPAWN_PIPE_NP(3C)


posix_spawn_pipe_np - spawn a process with connected pipe


#include <spawn.h>

int posix_spawn_pipe_np(pid_t *restrict pid,
int *restrict fdp,
const char *restrict cmd,
boolean_t write,
const posix_spawn_file_actions_t *file_actions,
const posix_spawnattr_t *restrict attr);


The posix_spawn_pipe_np() function creates a new process (child process)
to run sh -c cmd, and connects the new process's standard input or output
to a file descriptor.

The new process's environment (the environ global variable) is inherited
from the current process.

The cmd argument is the string for the child shell process to execute.

If the write argument is set, the returned file descriptor will be
connected to the new process's standard input, and will be opened for
writing. Otherwise, the file descriptor will be connected to the new
process's standard output, and will be opened for reading.

If file_actions is not NULL, then the file descriptors open in the child
process are those open in the calling process as modified by the spawn
file actions object pointed to by file_actions and the FD_CLOEXEC flag of
each remaining open file descriptor after the spawn file actions have
been processed. See posix_spawn(3C) for details on the behavior of

If attr is not NULL, then the signal mask, signal default or ignore
actions, and the effective user and group IDs for the child process are
changed as specified in the attributes object referenced by attr. See
posix_spawn(3C) for details on the behavior of attr.

All process attributes, other than those influenced by the attributes set
in the object referenced by attr as specified above or by the file
descriptor manipulations specified in file_actions appear in the new
process image as though fork() had been called to create a child process
and then a member of the exec family of functions had been called by the
child process to execute /bin/sh.

The fork handlers are not run when posix_spawn_pipe_np() is called.


Upon successful completion, posix_spawn_pipe_np() returns the process ID
of the child process to the parent process in the variable pointed to by
a non-null pidp argument, returns the file descriptor which is connected
to the child process in the variable pointed to by a non-null fdp
argument, and returns zero as the function return value. Otherwise, no
child process is created, the value stored into the variable pointed to
by a non-null pidp and fdp is unspecified, and an error number is
returned as the function return value to indicate the error.


See posix_spawn(3C).


See attributes(7) for descriptions of the following attributes:

|Interface Stability | Committed |
|MT-Level | MT-Safe |


exec(2), fork(2), open(2), popen(3C), posix_spawn(3C),
posix_spawn_file_actions_destroy(3C), posix_spawn_file_actions_init(3C),
posix_spawnattr_destroy(3C), posix_spawnattr_getflags(3C),
posix_spawnattr_getpgroup(3C), posix_spawnattr_getschedparam(3C),
posix_spawnattr_getschedpolicy(3C), posix_spawnattr_getsigdefault(3C),
posix_spawnattr_getsigignore_np(3C), posix_spawnattr_getsigmask(3C),
posix_spawnattr_init(3C), posix_spawnattr_setflags(3C),
posix_spawnattr_setpgroup(3C), posix_spawnattr_setschedparam(3C),
posix_spawnattr_setschedpolicy(3C), posix_spawnattr_setsigdefault(3C),
posix_spawnattr_setsigignore_np(3C), posix_spawnattr_setsigmask(3C),
system(3C), wait(3C), attributes(7), standards(7)

October 14, 2011 POSIX_SPAWN_PIPE_NP(3C)