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::{
6    BlockId,
7    engine::CommandType,
8    shell_error::{self, io::IoError},
9};
10use std::path::PathBuf;
11
12/// Source a file for environment variables.
13#[derive(Clone)]
14pub struct SourceEnv;
15
16impl Command for SourceEnv {
17    fn name(&self) -> &str {
18        "source-env"
19    }
20
21    fn signature(&self) -> Signature {
22        Signature::build("source-env")
23            .input_output_types(vec![(Type::Any, Type::Any)])
24            .required(
25                "filename",
26                SyntaxShape::OneOf(vec![SyntaxShape::String, SyntaxShape::Nothing]), // type is string to avoid automatically canonicalizing the path
27                "The filepath to the script file to source the environment from (`null` for no-op).",
28            )
29            .category(Category::Core)
30    }
31
32    fn description(&self) -> &str {
33        "Source the environment from a source file into the current environment."
34    }
35
36    fn extra_description(&self) -> &str {
37        r#"This command is a parser keyword. For details, check:
38  https://www.nushell.sh/book/thinking_in_nu.html"#
39    }
40
41    fn command_type(&self) -> CommandType {
42        CommandType::Keyword
43    }
44
45    fn run(
46        &self,
47        engine_state: &EngineState,
48        caller_stack: &mut Stack,
49        call: &Call,
50        input: PipelineData,
51    ) -> Result<PipelineData, ShellError> {
52        if call.get_parser_info(caller_stack, "noop").is_some() {
53            return Ok(PipelineData::empty());
54        }
55
56        let source_filename: Spanned<String> = call.req(engine_state, caller_stack, 0)?;
57
58        // Note: this hidden positional is the block_id that corresponded to the 0th position
59        // it is put here by the parser
60        let block_id: i64 = call.req_parser_info(engine_state, caller_stack, "block_id")?;
61        let block_id = BlockId::new(block_id as usize);
62
63        // Set the currently evaluated directory (file-relative PWD)
64        let file_path = if let Some(path) = find_in_dirs_env(
65            &source_filename.item,
66            engine_state,
67            caller_stack,
68            get_dirs_var_from_call(caller_stack, call),
69        )? {
70            PathBuf::from(&path)
71        } else {
72            return Err(ShellError::Io(IoError::new(
73                shell_error::io::ErrorKind::FileNotFound,
74                source_filename.span,
75                PathBuf::from(source_filename.item),
76            )));
77        };
78
79        if let Some(parent) = file_path.parent() {
80            let file_pwd = Value::string(parent.to_string_lossy(), call.head);
81
82            caller_stack.add_env_var("FILE_PWD".to_string(), file_pwd);
83        }
84
85        caller_stack.add_env_var(
86            "CURRENT_FILE".to_string(),
87            Value::string(file_path.to_string_lossy(), call.head),
88        );
89
90        // Evaluate the block
91        let block = engine_state.get_block(block_id).clone();
92        let mut callee_stack = caller_stack
93            .gather_captures(engine_state, &block.captures)
94            .reset_pipes();
95
96        let eval_block_with_early_return = get_eval_block_with_early_return(engine_state);
97
98        let result = eval_block_with_early_return(engine_state, &mut callee_stack, &block, input);
99
100        // Merge the block's environment to the current stack
101        redirect_env(engine_state, caller_stack, &callee_stack);
102
103        // Remove the file-relative PWD
104        caller_stack.remove_env_var(engine_state, "FILE_PWD");
105        caller_stack.remove_env_var(engine_state, "CURRENT_FILE");
106
107        result
108    }
109
110    fn examples(&self) -> Vec<Example> {
111        vec![
112            Example {
113                description: "Sources the environment from foo.nu in the current context",
114                example: r#"source-env foo.nu"#,
115                result: None,
116            },
117            Example {
118                description: "Sourcing `null` is a no-op.",
119                example: r#"source-env null"#,
120                result: None,
121            },
122        ]
123    }
124}
nu_command/env/source_env.rs

nu_command/env/
source_env.rs
