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::{have_permission, PermissionResult};
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 directory."
17    }
18
19    fn search_terms(&self) -> Vec<&str> {
20        vec!["change", "directory", "dir", "folder", "switch"]
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: Option<Spanned<String>> = call.opt(engine_state, stack, 0)?;
41
42        // If getting PWD failed, default to the home directory. The user can
43        // use `cd` to reset PWD to a good state.
44        let cwd = engine_state
45            .cwd(Some(stack))
46            .ok()
47            .or_else(nu_path::home_dir)
48            .map(|path| path.into_std_path_buf())
49            .unwrap_or_default();
50
51        let path_val = {
52            if let Some(path) = path_val {
53                Some(Spanned {
54                    item: nu_utils::strip_ansi_string_unlikely(path.item),
55                    span: path.span,
56                })
57            } else {
58                path_val
59            }
60        };
61
62        let path = match path_val {
63            Some(v) => {
64                if v.item == "-" {
65                    if let Some(oldpwd) = stack.get_env_var(engine_state, "OLDPWD") {
66                        oldpwd.to_path()?
67                    } else {
68                        cwd
69                    }
70                } else {
71                    // Trim whitespace from the end of path.
72                    let path_no_whitespace =
73                        &v.item.trim_end_matches(|x| matches!(x, '\x09'..='\x0d'));
74
75                    // If `--physical` is specified, canonicalize the path; otherwise expand the path.
76                    if physical {
77                        if let Ok(path) = nu_path::canonicalize_with(path_no_whitespace, &cwd) {
78                            if !path.is_dir() {
79                                return Err(shell_error::io::IoError::new(
80                                    shell_error::io::ErrorKind::Std(
81                                        std::io::ErrorKind::NotADirectory,
82                                    ),
83                                    v.span,
84                                    None,
85                                )
86                                .into());
87                            };
88                            path
89                        } else {
90                            return Err(shell_error::io::IoError::new(
91                                ErrorKind::DirectoryNotFound,
92                                v.span,
93                                PathBuf::from(path_no_whitespace),
94                            )
95                            .into());
96                        }
97                    } else {
98                        let path = nu_path::expand_path_with(path_no_whitespace, &cwd, true);
99                        if !path.exists() {
100                            return Err(shell_error::io::IoError::new(
101                                ErrorKind::DirectoryNotFound,
102                                v.span,
103                                PathBuf::from(path_no_whitespace),
104                            )
105                            .into());
106                        };
107                        if !path.is_dir() {
108                            return Err(shell_error::io::IoError::new(
109                                shell_error::io::ErrorKind::Std(std::io::ErrorKind::NotADirectory),
110                                v.span,
111                                path,
112                            )
113                            .into());
114                        };
115                        path
116                    }
117                }
118            }
119            None => nu_path::expand_tilde("~"),
120        };
121
122        // Set OLDPWD.
123        // We're using `Stack::get_env_var()` instead of `EngineState::cwd()` to avoid a conversion roundtrip.
124        if let Some(oldpwd) = stack.get_env_var(engine_state, "PWD") {
125            stack.add_env_var("OLDPWD".into(), oldpwd.clone())
126        }
127
128        match have_permission(&path) {
129            //FIXME: this only changes the current scope, but instead this environment variable
130            //should probably be a block that loads the information from the state in the overlay
131            PermissionResult::PermissionOk => {
132                stack.set_cwd(path)?;
133                Ok(PipelineData::empty())
134            }
135            PermissionResult::PermissionDenied(_) => {
136                Err(IoError::new(std::io::ErrorKind::PermissionDenied, call.head, path).into())
137            }
138        }
139    }
140
141    fn examples(&self) -> Vec<Example> {
142        vec![
143            Example {
144                description: "Change to your home directory",
145                example: r#"cd ~"#,
146                result: None,
147            },
148            Example {
149                description: r#"Change to the previous working directory (same as "cd $env.OLDPWD")"#,
150                example: r#"cd -"#,
151                result: None,
152            },
153            Example {
154                description: "Changing directory with a custom command requires 'def --env'",
155                example: r#"def --env gohome [] { cd ~ }"#,
156                result: None,
157            },
158            Example {
159                description: "Move two directories up in the tree (the parent directory's parent). Additional dots can be added for additional levels.",
160                example: r#"cd ..."#,
161                result: None,
162            },
163            Example {
164                description: "The cd command itself is often optional. Simply entering a path to a directory will cd to it.",
165                example: r#"/home"#,
166                result: None,
167            },
168        ]
169    }
170}
nu_command/filesystem/cd.rs

nu_command/filesystem/
cd.rs
