Tribblix: manual page: posix_spawn_pipe

POSIX_SPAWN_PIPE_NP(3C) Standard C Library Functions

NAME

posix_spawn_pipe_np - spawn a process with connected pipe

SYNOPSIS

#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);

DESCRIPTION

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 file_actions.

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.

RETURN VALUES

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.

ERRORS

See posix_spawn(3C).