expectrl 0.8.0

A tool for automating terminal applications in Unix like Don libes expect
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
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157

//! This module container a [LogStream]
//! which can wrap other streams in order to log a read/write operations.

use std::{
    io::{self, Read, Result, Write},
    ops::{Deref, DerefMut},
};

#[cfg(feature = "async")]
use futures_lite::{AsyncRead, AsyncWrite};
#[cfg(feature = "async")]
use std::{
    pin::Pin,
    task::{Context, Poll},
};

use crate::process::NonBlocking;

/// LogStream a IO stream wrapper,
/// which logs each write/read operation.
#[derive(Debug)]
pub struct LogStream<S, W> {
    stream: S,
    logger: W,
}

impl<S, W> LogStream<S, W> {
    /// Creates a new instance of the stream.
    pub fn new(stream: S, logger: W) -> Self {
        Self { stream, logger }
    }
}

impl<S, W: Write> LogStream<S, W> {
    fn log_write(&mut self, buf: &[u8]) {
        log(&mut self.logger, "write", buf);
    }

    fn log_read(&mut self, buf: &[u8]) {
        log(&mut self.logger, "read", buf);
    }
}

impl<S: Write, W: Write> Write for LogStream<S, W> {
    fn write(&mut self, buf: &[u8]) -> Result<usize> {
        let n = self.stream.write(buf)?;
        self.log_write(&buf[..n]);
        Ok(n)
    }

    fn flush(&mut self) -> Result<()> {
        self.stream.flush()
    }

    fn write_vectored(&mut self, bufs: &[io::IoSlice<'_>]) -> Result<usize> {
        let n = self.stream.write_vectored(bufs)?;

        let mut rest = n;
        let mut bytes = Vec::new();
        for buf in bufs {
            let written = std::cmp::min(buf.len(), rest);
            rest -= written;

            bytes.extend(&buf.as_ref()[..written]);

            if rest == 0 {
                break;
            }
        }

        self.log_write(&bytes);

        Ok(n)
    }
}

impl<S: Read, W: Write> Read for LogStream<S, W> {
    fn read(&mut self, buf: &mut [u8]) -> Result<usize> {
        let n = self.stream.read(buf)?;
        self.log_read(&buf[..n]);
        Ok(n)
    }
}

impl<S, W> NonBlocking for LogStream<S, W>
where
    S: NonBlocking,
{
    fn set_blocking(&mut self, on: bool) -> Result<()> {
        self.stream.set_blocking(on)
    }
}

impl<S, W> Deref for LogStream<S, W> {
    type Target = S;

    fn deref(&self) -> &Self::Target {
        &self.stream
    }
}

impl<S, W> DerefMut for LogStream<S, W> {
    fn deref_mut(&mut self) -> &mut Self::Target {
        &mut self.stream
    }
}

#[cfg(feature = "async")]
impl<S: AsyncWrite + Unpin, W: Write + Unpin> AsyncWrite for LogStream<S, W> {
    fn poll_write(
        mut self: Pin<&mut Self>,
        cx: &mut Context<'_>,
        buf: &[u8],
    ) -> Poll<Result<usize>> {
        self.log_write(buf);
        Pin::new(&mut self.get_mut().stream).poll_write(cx, buf)
    }

    fn poll_flush(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>> {
        Pin::new(&mut self.stream).poll_flush(cx)
    }

    fn poll_close(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>> {
        Pin::new(&mut self.stream).poll_close(cx)
    }

    fn poll_write_vectored(
        mut self: Pin<&mut Self>,
        cx: &mut Context<'_>,
        bufs: &[io::IoSlice<'_>],
    ) -> Poll<Result<usize>> {
        Pin::new(&mut self.stream).poll_write_vectored(cx, bufs)
    }
}

#[cfg(feature = "async")]
impl<S: AsyncRead + Unpin, W: Write + Unpin> AsyncRead for LogStream<S, W> {
    fn poll_read(
        mut self: Pin<&mut Self>,
        cx: &mut Context<'_>,
        buf: &mut [u8],
    ) -> Poll<Result<usize>> {
        let result = Pin::new(&mut self.stream).poll_read(cx, buf);
        if let Poll::Ready(Ok(n)) = &result {
            self.log_read(&buf[..*n]);
        }

        result
    }
}

fn log(mut writer: impl Write, target: &str, data: &[u8]) {
    let _ = match std::str::from_utf8(data) {
        Ok(data) => writeln!(writer, "{}: {:?}", target, data),
        Err(..) => writeln!(writer, "{}:(bytes): {:?}", target, data),
    };
}