bashers 0.8.8

Installable cli helpers
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

use anyhow::{Context, Result};
use std::process::Command;
use std::time::Duration;

use crate::utils::colors::Colors;
use diff;

pub fn run(command: &[String], interval_secs: u64, no_diff: bool) -> Result<()> {
    if command.is_empty() {
        anyhow::bail!("command cannot be empty");
    }
    let program = &command[0];
    let args = &command[1..];

    ctrlc::set_handler(move || std::process::exit(0)).context("setting Ctrl+C handler")?;

    let mut colors = Colors::new();
    let mut previous: Option<String> = None;

    loop {
        let output = run_cmd(program, args)?;
        clear_screen();
        let show_diff = !no_diff && previous.is_some();
        print_header(interval_secs, command, &mut colors, show_diff)?;

        if no_diff {
            let _ = colors.reset();
            let _ = colors.println(&output);
        } else if let Some(ref prev) = previous {
            print_diff(prev, &output, &mut colors)?;
        } else {
            let _ = colors.reset();
            let _ = colors.println(&output);
        }
        previous = Some(output);

        let _ = colors.reset();
        let _ = colors.flush();
        std::thread::sleep(Duration::from_secs(interval_secs));
    }
}

fn run_cmd(program: &str, args: &[String]) -> Result<String> {
    let out = Command::new(program)
        .args(args)
        .output()
        .with_context(|| format!("running {} {}", program, args.join(" ")))?;
    let mut s = String::from_utf8_lossy(&out.stdout).into_owned();
    if !out.stderr.is_empty() {
        s.push_str(&String::from_utf8_lossy(&out.stderr));
    }
    if s.ends_with('\n') {
        s.pop();
    }
    Ok(s)
}

fn clear_screen() {
    print!("\x1b[2J\x1b[H");
}

fn print_header(
    interval_secs: u64,
    command: &[String],
    colors: &mut Colors,
    show_diff_hint: bool,
) -> std::io::Result<()> {
    let _ = colors.cyan();
    let _ = colors.bold();
    let _ = colors.print(&format!("Every {}s: ", interval_secs));
    let _ = colors.reset();
    let _ = colors.println(&command.join(" "));
    if show_diff_hint {
        let _ = colors.green();
        let _ = colors.print("green");
        let _ = colors.reset();
        let _ = colors.println(" = changed since last run");
    }
    let _ = colors.println("");
    Ok(())
}

fn print_diff(prev: &str, curr: &str, colors: &mut Colors) -> std::io::Result<()> {
    let results = diff::lines(prev, curr);
    let mut pending_lefts: Vec<&str> = Vec::new();
    for r in results {
        match r {
            diff::Result::Left(line) => {
                pending_lefts.push(line);
            }
            diff::Result::Both(prev_line, curr_line) => {
                print_line_char_diff(prev_line, curr_line, colors)?;
            }
            diff::Result::Right(curr_line) => {
                if let Some(prev_line) = pending_lefts.pop() {
                    print_line_char_diff(prev_line, curr_line, colors)?;
                } else {
                    let _ = colors.green();
                    let _ = colors.println(curr_line);
                }
            }
        }
    }
    Ok(())
}

fn print_line_char_diff(
    prev_line: &str,
    curr_line: &str,
    colors: &mut Colors,
) -> std::io::Result<()> {
    let mut normal = String::new();
    let mut green = String::new();
    for r in diff::chars(prev_line, curr_line) {
        match r {
            diff::Result::Left(_) => {}
            diff::Result::Both(c, _) => {
                if !green.is_empty() {
                    let _ = colors.green();
                    let _ = colors.print(&green);
                    let _ = colors.reset();
                    green.clear();
                }
                normal.push(c);
            }
            diff::Result::Right(c) => {
                if !normal.is_empty() {
                    let _ = colors.reset();
                    let _ = colors.print(&normal);
                    normal.clear();
                }
                green.push(c);
            }
        }
    }
    let _ = colors.reset();
    let _ = colors.print(&normal);
    let _ = colors.green();
    let _ = colors.print(&green);
    let _ = colors.reset();
    let _ = colors.println("");
    Ok(())
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_run_empty_command_errors() {
        let err = run(&[], 1, false).unwrap_err();
        assert!(err.to_string().contains("empty"));
    }
}