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

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include <spawn.h>

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

DESCRIPTION

The posix_spawn_pipe_np() function creates a new process (child
process) which executes the command cmd as if by passing it to /bin/sh
with the -c flag, 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 values stored into the
variables pointed to by a non-null pidp and fdp are unspecified, and an
error number is returned as the function return value to indicate the
error.

ERRORS

See posix_spawn(3C).

INTERFACE STABILITY

Committed

MT-LEVEL
MT-Safe