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 = "echo hello";
94        let output = run_piped(cmd, "", None).unwrap();
95        assert!(output.trim().contains("hello"));
96    }
97
98    #[test]
99    fn test_input_piping() {
100        let cmd = if cfg!(windows) {
101            "findstr foo"
102        } else {
103            "grep foo"
104        };
105        let input = "foo\nbar\nbaz";
106        let output = run_piped(cmd, input, None).unwrap();
107        assert_eq!(output.trim(), "foo");
108    }
109
110    #[test]
111    fn test_timeout() {
112        let cmd = if cfg!(windows) {
113            "ping -n 3 127.0.0.1"
114        } else {
115            "sleep 2"
116        };
117        let start = std::time::Instant::now();
118        let res = run_piped(cmd, "", Some(Duration::from_millis(500)));
119        assert!(matches!(res, Err(ShellError::Timeout(_, _))));
120        assert!(start.elapsed() < Duration::from_secs(2));
121    }
122
123    #[test]
124    fn test_command_failed_includes_command_name() {
125        let cmd = "exit 1";
126        let res = run_piped(cmd, "", None);
127        match res {
128            Err(ShellError::CommandFailed(cmd_str, _)) => {
129                assert_eq!(cmd_str, cmd);
130            }
131            _ => panic!("Expected CommandFailed error"),
132        }
133    }
134}
standout_pipe/shell.rs

standout_pipe/
shell.rs
