nu_command/env/
source_env.rs

1use nu_engine::{
2    command_prelude::*, find_in_dirs_env, get_dirs_var_from_call, get_eval_block_with_early_return,
3    redirect_env,
4};
5use nu_protocol::{engine::CommandType, shell_error::io::IoError, BlockId};
6use std::path::PathBuf;
7
8/// Source a file for environment variables.
9#[derive(Clone)]
10pub struct SourceEnv;
11
12impl Command for SourceEnv {
13    fn name(&self) -> &str {
14        "source-env"
15    }
16
17    fn signature(&self) -> Signature {
18        Signature::build("source-env")
19            .input_output_types(vec![(Type::Any, Type::Any)])
20            .required(
21                "filename",
22                SyntaxShape::OneOf(vec![SyntaxShape::String, SyntaxShape::Nothing]), // type is string to avoid automatically canonicalizing the path
23                "The filepath to the script file to source the environment from (`null` for no-op).",
24            )
25            .category(Category::Core)
26    }
27
28    fn description(&self) -> &str {
29        "Source the environment from a source file into the current environment."
30    }
31
32    fn extra_description(&self) -> &str {
33        r#"This command is a parser keyword. For details, check:
34  https://www.nushell.sh/book/thinking_in_nu.html"#
35    }
36
37    fn command_type(&self) -> CommandType {
38        CommandType::Keyword
39    }
40
41    fn run(
42        &self,
43        engine_state: &EngineState,
44        caller_stack: &mut Stack,
45        call: &Call,
46        input: PipelineData,
47    ) -> Result<PipelineData, ShellError> {
48        if call.get_parser_info(caller_stack, "noop").is_some() {
49            return Ok(PipelineData::empty());
50        }
51
52        let source_filename: Spanned<String> = call.req(engine_state, caller_stack, 0)?;
53
54        // Note: this hidden positional is the block_id that corresponded to the 0th position
55        // it is put here by the parser
56        let block_id: i64 = call.req_parser_info(engine_state, caller_stack, "block_id")?;
57        let block_id = BlockId::new(block_id as usize);
58
59        // Set the currently evaluated directory (file-relative PWD)
60        let file_path = if let Some(path) = find_in_dirs_env(
61            &source_filename.item,
62            engine_state,
63            caller_stack,
64            get_dirs_var_from_call(caller_stack, call),
65        )? {
66            PathBuf::from(&path)
67        } else {
68            return Err(ShellError::Io(IoError::new(
69                std::io::ErrorKind::NotFound,
70                source_filename.span,
71                PathBuf::from(source_filename.item),
72            )));
73        };
74
75        if let Some(parent) = file_path.parent() {
76            let file_pwd = Value::string(parent.to_string_lossy(), call.head);
77
78            caller_stack.add_env_var("FILE_PWD".to_string(), file_pwd);
79        }
80
81        caller_stack.add_env_var(
82            "CURRENT_FILE".to_string(),
83            Value::string(file_path.to_string_lossy(), call.head),
84        );
85
86        // Evaluate the block
87        let block = engine_state.get_block(block_id).clone();
88        let mut callee_stack = caller_stack
89            .gather_captures(engine_state, &block.captures)
90            .reset_pipes();
91
92        let eval_block_with_early_return = get_eval_block_with_early_return(engine_state);
93
94        let result = eval_block_with_early_return(engine_state, &mut callee_stack, &block, input);
95
96        // Merge the block's environment to the current stack
97        redirect_env(engine_state, caller_stack, &callee_stack);
98
99        // Remove the file-relative PWD
100        caller_stack.remove_env_var(engine_state, "FILE_PWD");
101        caller_stack.remove_env_var(engine_state, "CURRENT_FILE");
102
103        result
104    }
105
106    fn examples(&self) -> Vec<Example> {
107        vec![
108            Example {
109                description: "Sources the environment from foo.nu in the current context",
110                example: r#"source-env foo.nu"#,
111                result: None,
112            },
113            Example {
114                description: "Sourcing `null` is a no-op.",
115                example: r#"source-env null"#,
116                result: None,
117            },
118        ]
119    }
120}
nu_command/env/source_env.rs

nu_command/env/
source_env.rs
