standout_pipe/
shell.rs

1use std::io::Write;
2use std::process::{Command, Stdio};
3use std::time::Duration;
4use thiserror::Error;
5use wait_timeout::ChildExt;
6
7#[derive(Debug, Error)]
8pub enum ShellError {
9    #[error("IO error: {0}")]
10    Io(#[from] std::io::Error),
11    #[error("Command `{0}` timed out after {1:?}")]
12    Timeout(String, Duration),
13    #[error("Command `{0}` failed with status {1}")]
14    CommandFailed(String, std::process::ExitStatus),
15    #[error("Command output was not valid UTF-8")]
16    InvalidUtf8(#[from] std::string::FromUtf8Error),
17}
18
19/// Execute a shell command with the given input piped to stdin.
20///
21/// Returns the command's stdout on success.
22///
23/// # Arguments
24///
25/// * `command_str` - The shell command to execute
26/// * `input` - Data to write to the command's stdin
27/// * `timeout` - Optional timeout; if exceeded, the process is killed
28///
29/// # Notes
30///
31/// The entire stdout is buffered in memory before being returned.
32/// For very large outputs (multi-megabyte), consider streaming alternatives.
33pub fn run_piped(
34    command_str: &str,
35    input: &str,
36    timeout: Option<Duration>,
37) -> Result<String, ShellError> {
38    let mut cmd = if cfg!(target_os = "windows") {
39        let mut c = Command::new("cmd");
40        c.arg("/C").arg(command_str);
41        c
42    } else {
43        let mut c = Command::new("sh");
44        c.arg("-c").arg(command_str);
45        c
46    };
47
48    cmd.stdin(Stdio::piped())
49        .stdout(Stdio::piped())
50        .stderr(Stdio::inherit());
51
52    let mut child = cmd.spawn()?;
53
54    if let Some(mut stdin) = child.stdin.take() {
55        stdin.write_all(input.as_bytes())?;
56    }
57
58    match timeout {
59        Some(duration) => match child.wait_timeout(duration)? {
60            Some(status) => {
61                if !status.success() {
62                    return Err(ShellError::CommandFailed(command_str.to_string(), status));
63                }
64            }
65            None => {
66                child.kill()?;
67                return Err(ShellError::Timeout(command_str.to_string(), duration));
68            }
69        },
70        None => {
71            let status = child.wait()?;
72            if !status.success() {
73                return Err(ShellError::CommandFailed(command_str.to_string(), status));
74            }
75        }
76    }
77
78    let mut output = String::new();
79    if let Some(mut stdout) = child.stdout.take() {
80        use std::io::Read;
81        stdout.read_to_string(&mut output)?;
82    }
83
84    Ok(output)
85}
86
87#[cfg(test)]
88mod tests {
89    use super::*;
90
91    #[test]
92    fn test_echo() {
93        let cmd = if cfg!(windows) {
94            "echo hello"
95        } else {
96            "echo hello"
97        };
98        let output = run_piped(cmd, "", None).unwrap();
99        assert!(output.trim().contains("hello"));
100    }
101
102    #[test]
103    fn test_input_piping() {
104        let cmd = if cfg!(windows) {
105            "findstr foo"
106        } else {
107            "grep foo"
108        };
109        let input = "foo\nbar\nbaz";
110        let output = run_piped(cmd, input, None).unwrap();
111        assert_eq!(output.trim(), "foo");
112    }
113
114    #[test]
115    fn test_timeout() {
116        let cmd = if cfg!(windows) {
117            "ping -n 3 127.0.0.1"
118        } else {
119            "sleep 2"
120        };
121        let start = std::time::Instant::now();
122        let res = run_piped(cmd, "", Some(Duration::from_millis(500)));
123        assert!(matches!(res, Err(ShellError::Timeout(_, _))));
124        assert!(start.elapsed() < Duration::from_secs(2));
125    }
126
127    #[test]
128    fn test_command_failed_includes_command_name() {
129        let cmd = if cfg!(windows) { "exit 1" } else { "exit 1" };
130        let res = run_piped(cmd, "", None);
131        match res {
132            Err(ShellError::CommandFailed(cmd_str, _)) => {
133                assert_eq!(cmd_str, cmd);
134            }
135            _ => panic!("Expected CommandFailed error"),
136        }
137    }
138}
standout_pipe/shell.rs

standout_pipe/
shell.rs
