shrub-core 0.0.3

Reusable core of a POSIX/bash shell (used by shrub-shell)
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138

//! Signal processing utilities

use crate::{error, sys, traps};

/// A stub enum representing system signals on unsupported platforms.
#[allow(unnameable_types)]
#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
pub enum Signal {}

impl Signal {
    /// Returns an iterator over all possible signals.
    pub fn iterator() -> impl Iterator<Item = Self> {
        std::iter::empty()
    }

    /// Converts the signal into its corresponding name as a `&'static str`.
    pub const fn as_str(self) -> &'static str {
        ""
    }

    /// Creates a `Signal` from a string representation.
    ///
    /// # Errors
    ///
    /// Always returns [`crate::error::ErrorKind::InvalidSignal`], because this
    /// platform has no signals.
    pub fn from_str(s: &str) -> Result<Self, error::Error> {
        Err(error::ErrorKind::InvalidSignal(s.into()).into())
    }
}

impl TryFrom<i32> for Signal {
    type Error = error::Error;

    fn try_from(value: i32) -> Result<Self, Self::Error> {
        Err(error::ErrorKind::InvalidSignal(std::format!("{value}")).into())
    }
}

pub(crate) fn continue_process(_pid: sys::process::ProcessId) -> Result<(), error::Error> {
    Err(error::ErrorKind::NotSupportedOnThisPlatform("continuing process").into())
}

pub(crate) fn continue_process_group(_pgid: sys::process::ProcessId) -> Result<(), error::Error> {
    Err(error::ErrorKind::NotSupportedOnThisPlatform("continuing process group").into())
}

/// Checks whether a specific process exists and can be signaled.
///
/// This is a stub implementation that returns an error.
///
/// # Errors
///
/// Always returns [`crate::error::ErrorKind::NotSupportedOnThisPlatform`] on
/// this platform (checking process).
pub fn check_signalable(_pid: sys::process::ProcessId) -> Result<(), error::Error> {
    Err(error::ErrorKind::NotSupportedOnThisPlatform("checking process").into())
}

/// Sends a signal to a specific process.
///
/// This is a stub implementation that returns an error.
///
/// # Errors
///
/// Always returns [`crate::error::ErrorKind::NotSupportedOnThisPlatform`] on
/// this platform (killing process).
pub fn kill_process(
    _pid: sys::process::ProcessId,
    _signal: traps::TrapSignal,
) -> Result<(), error::Error> {
    Err(error::ErrorKind::NotSupportedOnThisPlatform("killing process").into())
}

pub(crate) fn check_process_group_signalable(
    _pgid: sys::process::ProcessId,
) -> Result<(), error::Error> {
    Err(error::ErrorKind::NotSupportedOnThisPlatform("checking process group").into())
}

pub(crate) fn kill_process_group(
    _pgid: sys::process::ProcessId,
    _signal: traps::TrapSignal,
) -> Result<(), error::Error> {
    Err(error::ErrorKind::NotSupportedOnThisPlatform("killing process group").into())
}

pub(crate) const fn continue_stopped_on(_signal: traps::TrapSignal) -> bool {
    false
}

pub(crate) fn lead_new_process_group() -> Result<(), error::Error> {
    Ok(())
}

pub(crate) struct FakeSignal {}

impl FakeSignal {
    fn new() -> Self {
        Self {}
    }

    pub async fn recv(&self) {
        futures::future::pending::<()>().await;
    }
}

pub(crate) fn tstp_signal_listener() -> Result<FakeSignal, error::Error> {
    Ok(FakeSignal::new())
}

pub(crate) fn chld_signal_listener() -> Result<FakeSignal, error::Error> {
    Ok(FakeSignal::new())
}

/// Waits for Ctrl-C; on this platform, it never arrives.
///
/// # Errors
///
/// This stub implementation never returns an error.
pub async fn await_ctrl_c() -> std::io::Result<()> {
    FakeSignal::new().recv().await;
    Ok(())
}

pub(crate) fn mask_sigttou() -> Result<(), error::Error> {
    Ok(())
}

pub(crate) fn poll_for_stopped_children(
    _pid: sys::process::ProcessId,
) -> Result<bool, error::Error> {
    Ok(false)
}

pub(crate) fn poll_for_stopped_child(_pid: sys::process::ProcessId) -> Result<bool, error::Error> {
    Ok(false)
}