nu_command/filesystem/
cd.rs

1use std::path::PathBuf;
2
3use nu_engine::command_prelude::*;
4use nu_protocol::shell_error::{self, io::IoError};
5use nu_utils::filesystem::{PermissionResult, have_permission};
6
7#[derive(Clone)]
8pub struct Cd;
9
10impl Command for Cd {
11    fn name(&self) -> &str {
12        "cd"
13    }
14
15    fn description(&self) -> &str {
16        "Change the current working directory."
17    }
18
19    fn search_terms(&self) -> Vec<&str> {
20        vec!["change", "directory", "dir", "folder", "switch", "chdir"]
21    }
22
23    fn signature(&self) -> nu_protocol::Signature {
24        Signature::build("cd")
25            .input_output_types(vec![(Type::Nothing, Type::Nothing)])
26            .switch("physical", "Use the physical directory structure; resolve symbolic links before processing instances of ..", Some('P'))
27            .optional("path", SyntaxShape::Directory, "The path to change to.")
28            .allow_variants_without_examples(true)
29            .category(Category::FileSystem)
30    }
31
32    fn run(
33        &self,
34        engine_state: &EngineState,
35        stack: &mut Stack,
36        call: &Call,
37        _input: PipelineData,
38    ) -> Result<PipelineData, ShellError> {
39        let physical = call.has_flag(engine_state, stack, "physical")?;
40        let path_val = call
41            .opt::<Spanned<String>>(engine_state, stack, 0)?
42            .map(|p| p.map(nu_utils::strip_ansi_string_unlikely));
43
44        // If getting PWD failed, default to the home directory. The user can
45        // use `cd` to reset PWD to a good state.
46        let cwd = engine_state
47            .cwd(Some(stack))
48            .ok()
49            .or_else(nu_path::home_dir)
50            .map(|path| path.into_std_path_buf())
51            .unwrap_or_default();
52
53        let path = match path_val {
54            Some(v) => {
55                if v.item == "-" {
56                    if let Some(oldpwd) = stack.get_env_var(engine_state, "OLDPWD") {
57                        oldpwd.to_path()?
58                    } else {
59                        cwd
60                    }
61                } else {
62                    // Trim whitespace from the end of path.
63                    let path_no_whitespace =
64                        &v.item.trim_end_matches(|x| matches!(x, '\x09'..='\x0d'));
65
66                    // If `--physical` is specified, canonicalize the path; otherwise expand the path.
67                    if physical {
68                        if let Ok(path) = nu_path::canonicalize_with(path_no_whitespace, &cwd) {
69                            if !path.is_dir() {
70                                return Err(shell_error::io::IoError::new(
71                                    shell_error::io::ErrorKind::from_std(
72                                        std::io::ErrorKind::NotADirectory,
73                                    ),
74                                    v.span,
75                                    None,
76                                )
77                                .into());
78                            };
79                            path
80                        } else {
81                            return Err(shell_error::io::IoError::new(
82                                ErrorKind::DirectoryNotFound,
83                                v.span,
84                                PathBuf::from(path_no_whitespace),
85                            )
86                            .into());
87                        }
88                    } else {
89                        let path = nu_path::expand_path_with(path_no_whitespace, &cwd, true);
90                        if !path.exists() {
91                            return Err(shell_error::io::IoError::new(
92                                ErrorKind::DirectoryNotFound,
93                                v.span,
94                                PathBuf::from(path_no_whitespace),
95                            )
96                            .into());
97                        };
98                        if !path.is_dir() {
99                            return Err(shell_error::io::IoError::new(
100                                shell_error::io::ErrorKind::from_std(
101                                    std::io::ErrorKind::NotADirectory,
102                                ),
103                                v.span,
104                                path,
105                            )
106                            .into());
107                        };
108                        path
109                    }
110                }
111            }
112            None => nu_path::expand_tilde("~"),
113        };
114
115        // Set OLDPWD.
116        // We're using `Stack::get_env_var()` instead of `EngineState::cwd()` to avoid a conversion roundtrip.
117        if let Some(oldpwd) = stack.get_env_var(engine_state, "PWD") {
118            stack.add_env_var("OLDPWD".into(), oldpwd.clone())
119        }
120
121        match have_permission(&path) {
122            //FIXME: this only changes the current scope, but instead this environment variable
123            //should probably be a block that loads the information from the state in the overlay
124            PermissionResult::PermissionOk => {
125                stack.set_cwd(path)?;
126                Ok(PipelineData::empty())
127            }
128            PermissionResult::PermissionDenied => Err(IoError::new(
129                shell_error::io::ErrorKind::from_std(std::io::ErrorKind::PermissionDenied),
130                call.head,
131                path,
132            )
133            .into()),
134        }
135    }
136
137    fn examples(&self) -> Vec<Example<'_>> {
138        vec![
139            Example {
140                description: "Change to your home directory.",
141                example: "cd ~",
142                result: None,
143            },
144            Example {
145                description: r#"Change to the previous working directory (same as "cd $env.OLDPWD")."#,
146                example: "cd -",
147                result: None,
148            },
149            Example {
150                description: "Changing directory with a custom command requires 'def --env'.",
151                example: "def --env gohome [] { cd ~ }",
152                result: None,
153            },
154            Example {
155                description: "Move two directories up in the tree (the parent directory's parent). Additional dots can be added for additional levels.",
156                example: "cd ...",
157                result: None,
158            },
159            Example {
160                description: "The cd command itself is often optional. Simply entering a path to a directory will cd to it.",
161                example: "/home",
162                result: None,
163            },
164        ]
165    }
166}
nu_command/filesystem/cd.rs

nu_command/filesystem/
cd.rs
