nbdkit_stdio_safe3

Usage

 #include <nbdkit-plugin.h>
 int nbdkit_stdio_safe (void);

Overview

The "nbdkit_stdio_safe" utility function returns whether or not it is safe to interact with stdin and stdout during the configuration phase.

This is needed because when the nbdkit -s option is used the plugin must not directly interact with stdin, because that would interfere with network communication.

The result of this function only matters in callbacks up to ".config_complete". Once nbdkit reaches ".get_ready", the plugin should assume that nbdkit may have closed the original stdin and stdout in order to become a daemon.

nbdkit-sh-plugin(3) uses this function to determine whether it is safe to support "script=-" to read a script from stdin. Also constructs like "password=-" (see nbdkit_read_password(3)) are disabled when reading from stdio is not safe.

Return value

The function returns 1 (safe) or 0 (not safe).

It cannot return an error.

Language bindings

In nbdkit-ocaml-plugin(3):

 NBDKit.stdio_safe : unit -> bool

In nbdkit-python-plugin(3):

 import nbdkit
 is_safe = nbdkit.stdio_safe()

In nbdkit-rust-plugin(3):

 use nbdkit::*;
 pub fn is_stdio_safe() -> bool