double_o/
exec.rs

1use std::process::Command;
2
3use crate::error::Error;
4
5/// Output from executing a shell command.
6///
7/// Captures the standard output, standard error, and exit status of a command
8/// executed via `run()`.
9pub struct CommandOutput {
10    /// Standard output as raw bytes.
11    pub stdout: Vec<u8>,
12
13    /// Standard error as raw bytes.
14    pub stderr: Vec<u8>,
15
16    /// Process exit code (0 indicates success).
17    pub exit_code: i32,
18}
19
20impl CommandOutput {
21    /// Merged output: stdout followed by stderr.
22    pub fn merged(&self) -> Vec<u8> {
23        let mut out = self.stdout.clone();
24        out.extend_from_slice(&self.stderr);
25        out
26    }
27
28    /// Merged output as a lossy UTF-8 string.
29    pub fn merged_lossy(&self) -> String {
30        String::from_utf8_lossy(&self.merged()).into_owned()
31    }
32}
33
34/// Execute a shell command and capture its output.
35///
36/// Runs the first argument as the program name with remaining arguments as parameters.
37/// Captures stdout, stderr, and exit status.
38///
39/// # Arguments
40///
41/// * `args` - Command arguments where the first element is the program name
42///
43/// # Returns
44///
45/// A `CommandOutput` containing stdout, stderr, and exit code
46///
47/// # Errors
48///
49/// Returns an error if the command cannot be spawned or if there's an I/O error during execution.
50///
51/// # Examples
52///
53/// ```
54/// use double_o::exec::run;
55///
56/// let output = run(&["echo".into(), "hello".into()]).unwrap();
57/// assert_eq!(output.exit_code, 0);
58/// assert!(String::from_utf8_lossy(&output.stdout).contains("hello"));
59/// ```
60pub fn run(args: &[String]) -> Result<CommandOutput, Error> {
61    let output = Command::new(&args[0]).args(&args[1..]).output()?;
62
63    let exit_code = output.status.code().unwrap_or(128);
64
65    Ok(CommandOutput {
66        stdout: output.stdout,
67        stderr: output.stderr,
68        exit_code,
69    })
70}
71
72#[cfg(test)]
73mod tests {
74    use super::*;
75
76    #[test]
77    fn test_successful_command() {
78        let result = run(&["echo".into(), "hello".into()]).unwrap();
79        assert_eq!(result.exit_code, 0);
80        assert_eq!(String::from_utf8_lossy(&result.stdout), "hello\n");
81    }
82
83    #[test]
84    fn test_failing_command() {
85        let result = run(&["false".into()]).unwrap();
86        assert_ne!(result.exit_code, 0);
87    }
88
89    #[test]
90    fn test_stderr_captured() {
91        let result = run(&["sh".into(), "-c".into(), "echo err >&2".into()]).unwrap();
92        assert_eq!(result.exit_code, 0);
93        assert_eq!(String::from_utf8_lossy(&result.stderr), "err\n");
94    }
95
96    #[test]
97    fn test_exit_code_preserved() {
98        let result = run(&["sh".into(), "-c".into(), "exit 42".into()]).unwrap();
99        assert_eq!(result.exit_code, 42);
100    }
101
102    #[test]
103    fn test_merged_output() {
104        let result = run(&["sh".into(), "-c".into(), "echo out; echo err >&2".into()]).unwrap();
105        let merged = result.merged_lossy();
106        assert!(merged.contains("out"));
107        assert!(merged.contains("err"));
108    }
109}
double_o/exec.rs

double_o/
exec.rs
