nu-command 0.106.0

Nushell's built-in commands
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

use std::borrow::Cow;

use nu_engine::{command_prelude::*, env_to_strings};

#[derive(Clone)]
pub struct Exec;

impl Command for Exec {
    fn name(&self) -> &str {
        "exec"
    }

    fn signature(&self) -> Signature {
        Signature::build("exec")
            .input_output_types(vec![(Type::Nothing, Type::Any)])
            .rest(
                "command",
                SyntaxShape::OneOf(vec![SyntaxShape::GlobPattern, SyntaxShape::Any]),
                "External command to run, with arguments.",
            )
            .allows_unknown_args()
            .category(Category::System)
    }

    fn description(&self) -> &str {
        "Execute a command, replacing or exiting the current process, depending on platform."
    }

    fn extra_description(&self) -> &str {
        r#"On Unix-based systems, the current process is replaced with the command.
On Windows based systems, Nushell will wait for the command to finish and then exit with the command's exit code."#
    }

    fn run(
        &self,
        engine_state: &EngineState,
        stack: &mut Stack,
        call: &Call,
        _input: PipelineData,
    ) -> Result<PipelineData, ShellError> {
        let cwd = engine_state.cwd(Some(stack))?;
        let rest = call.rest::<Value>(engine_state, stack, 0)?;
        let name_args = rest.split_first();

        let Some((name, call_args)) = name_args else {
            return Err(ShellError::MissingParameter {
                param_name: "no command given".into(),
                span: call.head,
            });
        };

        let name_str: Cow<str> = match &name {
            Value::Glob { val, .. } => Cow::Borrowed(val),
            Value::String { val, .. } => Cow::Borrowed(val),
            _ => Cow::Owned(name.clone().coerce_into_string()?),
        };

        // Find the absolute path to the executable. If the command is not
        // found, display a helpful error message.
        let executable = {
            let paths = nu_engine::env::path_str(engine_state, stack, call.head)?;
            let Some(executable) = crate::which(name_str.as_ref(), &paths, cwd.as_ref()) else {
                return Err(crate::command_not_found(
                    &name_str,
                    call.head,
                    engine_state,
                    stack,
                    &cwd,
                ));
            };
            executable
        };

        // Create the command.
        let mut command = std::process::Command::new(executable);

        // Configure PWD.
        command.current_dir(cwd);

        // Configure environment variables.
        let envs = env_to_strings(engine_state, stack)?;
        command.env_clear();
        command.envs(envs);
        // Decrement SHLVL as removing the current shell from the stack
        // (only works in interactive mode, same as initialization)
        if engine_state.is_interactive {
            let shlvl = engine_state
                .get_env_var("SHLVL")
                .and_then(|shlvl_env| shlvl_env.coerce_str().ok()?.parse::<i64>().ok())
                .unwrap_or(1)
                .saturating_sub(1);
            command.env("SHLVL", shlvl.to_string());
        }

        // Configure args.
        let args = crate::eval_external_arguments(engine_state, stack, call_args.to_vec())?;
        command.args(args.into_iter().map(|s| s.item));

        // Execute the child process, replacing/terminating the current process
        // depending on platform.
        #[cfg(unix)]
        {
            use std::os::unix::process::CommandExt;

            let err = command.exec();
            Err(ShellError::ExternalCommand {
                label: "Failed to exec into new process".into(),
                help: err.to_string(),
                span: call.head,
            })
        }
        #[cfg(windows)]
        {
            let mut child = command.spawn().map_err(|err| ShellError::ExternalCommand {
                label: "Failed to exec into new process".into(),
                help: err.to_string(),
                span: call.head,
            })?;
            let status = child.wait().map_err(|err| ShellError::ExternalCommand {
                label: "Failed to wait for child process".into(),
                help: err.to_string(),
                span: call.head,
            })?;
            std::process::exit(status.code().expect("status.code() succeeds on Windows"))
        }
    }

    fn examples(&self) -> Vec<Example> {
        vec![
            Example {
                description: "Execute external 'ps aux' tool",
                example: "exec ps aux",
                result: None,
            },
            Example {
                description: "Execute 'nautilus'",
                example: "exec nautilus",
                result: None,
            },
        ]
    }
}