nu_command/help/
help_.rs

1use crate::help::{help_aliases, help_commands, help_modules};
2use nu_engine::command_prelude::*;
3
4#[derive(Clone)]
5pub struct Help;
6
7impl Command for Help {
8    fn name(&self) -> &str {
9        "help"
10    }
11
12    fn signature(&self) -> Signature {
13        Signature::build("help")
14            .input_output_types(vec![(Type::Nothing, Type::Any)])
15            .rest(
16                "rest",
17                SyntaxShape::String,
18                "The name of command, alias or module to get help on.",
19            )
20            .named(
21                "find",
22                SyntaxShape::String,
23                "string to find in command names, descriptions, and search terms",
24                Some('f'),
25            )
26            .category(Category::Core)
27    }
28
29    fn description(&self) -> &str {
30        "Display help information about different parts of Nushell."
31    }
32
33    fn extra_description(&self) -> &str {
34        r#"`help word` searches for "word" in commands, aliases and modules, in that order."#
35    }
36
37    fn run(
38        &self,
39        engine_state: &EngineState,
40        stack: &mut Stack,
41        call: &Call,
42        _input: PipelineData,
43    ) -> Result<PipelineData, ShellError> {
44        let head = call.head;
45        let find: Option<Spanned<String>> = call.get_flag(engine_state, stack, "find")?;
46        let rest: Vec<Spanned<String>> = call.rest(engine_state, stack, 0)?;
47
48        if rest.is_empty() && find.is_none() {
49            let msg = r#"Welcome to Nushell.
50
51Here are some tips to help you get started.
52  * help -h or help help - show available `help` subcommands and examples
53  * help commands - list all available commands
54  * help <name> - display help about a particular command, alias, or module
55  * help --find <text to search> - search through all help commands table
56
57Nushell works on the idea of a "pipeline". Pipelines are commands connected with the '|' character.
58Each stage in the pipeline works together to load, parse, and display information to you.
59
60[Examples]
61
62List the files in the current directory, sorted by size:
63    ls | sort-by size
64
65Get the current system host name:
66    sys host | get hostname
67
68Get the processes on your system actively using CPU:
69    ps | where cpu > 0
70
71You can also learn more at https://www.nushell.sh/book/"#;
72
73            Ok(Value::string(msg, head).into_pipeline_data())
74        } else if find.is_some() {
75            help_commands(engine_state, stack, call)
76        } else {
77            let result = help_aliases(engine_state, stack, call);
78
79            let result = if let Err(ShellError::AliasNotFound { .. }) = result {
80                help_commands(engine_state, stack, call)
81            } else {
82                result
83            };
84
85            let result = if let Err(ShellError::CommandNotFound { .. }) = result {
86                help_modules(engine_state, stack, call)
87            } else {
88                result
89            };
90
91            if let Err(ShellError::ModuleNotFoundAtRuntime {
92                mod_name: _,
93                span: _,
94            }) = result
95            {
96                Err(ShellError::NotFound {
97                    span: Span::merge_many(rest.iter().map(|s| s.span)),
98                })
99            } else {
100                result
101            }
102        }
103    }
104
105    fn examples(&self) -> Vec<Example> {
106        vec![
107            Example {
108                description: "show help for single command, alias, or module",
109                example: "help match",
110                result: None,
111            },
112            Example {
113                description: "show help for single sub-command, alias, or module",
114                example: "help str join",
115                result: None,
116            },
117            Example {
118                description: "search for string in command names, descriptions, and search terms",
119                example: "help --find char",
120                result: None,
121            },
122        ]
123    }
124}
nu_command/help/help_.rs

nu_command/help/
help_.rs
