armybox 0.3.0

A memory-safe #[no_std] BusyBox/Toybox clone in Rust - 299 Unix utilities in ~500KB
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

//! gpioset - set values of GPIO lines
//!
//! Set values of GPIO lines.

use crate::io;
use crate::sys;
use super::get_arg;

/// gpioset - set values of GPIO lines
///
/// # Synopsis
/// ```text
/// gpioset CHIP LINE=VALUE...
/// ```
///
/// # Description
/// Set values of one or more GPIO lines on a chip.
/// Values are 0 or 1.
///
/// # Exit Status
/// - 0: Success
/// - 1: Error
pub fn gpioset(argc: i32, argv: *const *const u8) -> i32 {
    if argc < 3 {
        io::write_str(2, b"gpioset: usage: gpioset CHIP LINE=VALUE...\n");
        return 1;
    }

    let chip = unsafe { get_arg(argv, 1).unwrap() };

    // Build device path
    let mut path = [0u8; 64];
    if chip.len() > 0 && chip[0] == b'/' {
        let len = chip.len().min(path.len() - 1);
        path[..len].copy_from_slice(&chip[..len]);
    } else {
        let prefix = b"/dev/";
        path[..prefix.len()].copy_from_slice(prefix);
        let len = chip.len().min(path.len() - prefix.len() - 1);
        path[prefix.len()..prefix.len() + len].copy_from_slice(&chip[..len]);
    }

    let fd = io::open(&path, libc::O_RDWR, 0);
    if fd < 0 {
        sys::perror(&path);
        return 1;
    }

    // Parse LINE=VALUE pairs
    for i in 2..argc {
        if let Some(arg) = unsafe { get_arg(argv, i) } {
            // Find '=' separator
            let mut eq_pos = None;
            for (j, &c) in arg.iter().enumerate() {
                if c == b'=' {
                    eq_pos = Some(j);
                    break;
                }
            }

            if let Some(pos) = eq_pos {
                let _line = sys::parse_u64(&arg[..pos]).unwrap_or(0);
                let _value = sys::parse_u64(&arg[pos + 1..]).unwrap_or(0);

                // Would need GPIO_SET_LINEHANDLE_IOCTL to actually set
                // For now, just acknowledge
            } else {
                io::write_str(2, b"gpioset: invalid argument: ");
                io::write_all(2, arg);
                io::write_str(2, b"\n");
            }
        }
    }

    io::close(fd);
    0
}

#[cfg(test)]
mod tests {
    extern crate std;
    use std::process::Command;
    use std::path::PathBuf;

    fn get_armybox_path() -> PathBuf {
        if let Ok(path) = std::env::var("ARMYBOX_PATH") {
            return PathBuf::from(path);
        }
        let manifest_dir = std::env::var("CARGO_MANIFEST_DIR")
            .map(PathBuf::from)
            .unwrap_or_else(|_| std::env::current_dir().unwrap());
        let release = manifest_dir.join("target/release/armybox");
        if release.exists() { return release; }
        manifest_dir.join("target/debug/armybox")
    }

    #[test]
    fn test_gpioset_no_args() {
        let armybox = get_armybox_path();
        if !armybox.exists() { return; }

        let output = Command::new(&armybox)
            .args(["gpioset"])
            .output()
            .unwrap();

        assert_eq!(output.status.code(), Some(1));
        let stderr = std::string::String::from_utf8_lossy(&output.stderr);
        assert!(stderr.contains("usage"));
    }

    #[test]
    fn test_gpioset_nonexistent_chip() {
        let armybox = get_armybox_path();
        if !armybox.exists() { return; }

        let output = Command::new(&armybox)
            .args(["gpioset", "nonexistent_chip", "0=1"])
            .output()
            .unwrap();

        assert_eq!(output.status.code(), Some(1));
    }
}