use crate::help::{help_aliases, help_commands, help_modules};
use nu_engine::command_prelude::*;
#[derive(Clone)]
pub struct Help;
impl Command for Help {
fn name(&self) -> &str {
"help"
}
fn signature(&self) -> Signature {
Signature::build("help")
.input_output_types(vec![(Type::Nothing, Type::Any)])
.rest(
"rest",
SyntaxShape::String,
"The name of command, alias or module to get help on.",
)
.named(
"find",
SyntaxShape::String,
"string to find in command names, descriptions, and search terms",
Some('f'),
)
.category(Category::Core)
}
fn description(&self) -> &str {
"Display help information about different parts of Nushell."
}
fn extra_description(&self) -> &str {
r#"`help word` searches for "word" in commands, aliases and modules, in that order."#
}
fn run(
&self,
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
_input: PipelineData,
) -> Result<PipelineData, ShellError> {
let head = call.head;
let find: Option<Spanned<String>> = call.get_flag(engine_state, stack, "find")?;
let rest: Vec<Spanned<String>> = call.rest(engine_state, stack, 0)?;
if rest.is_empty() && find.is_none() {
let msg = r#"Welcome to Nushell.
Here are some tips to help you get started.
* help -h or help help - show available `help` subcommands and examples
* help commands - list all available commands
* help <name> - display help about a particular command, alias, or module
* help --find <text to search> - search through all help commands table
Nushell works on the idea of a "pipeline". Pipelines are commands connected with the '|' character.
Each stage in the pipeline works together to load, parse, and display information to you.
[Examples]
List the files in the current directory, sorted by size:
ls | sort-by size
Get the current system host name:
sys host | get hostname
Get the processes on your system actively using CPU:
ps | where cpu > 0
You can also learn more at https://www.nushell.sh/book/"#;
Ok(Value::string(msg, head).into_pipeline_data())
} else if find.is_some() {
help_commands(engine_state, stack, call)
} else {
let result = help_aliases(engine_state, stack, call);
let result = if let Err(ShellError::AliasNotFound { .. }) = result {
help_commands(engine_state, stack, call)
} else {
result
};
let result = if let Err(ShellError::CommandNotFound { .. }) = result {
help_modules(engine_state, stack, call)
} else {
result
};
if let Err(ShellError::ModuleNotFoundAtRuntime {
mod_name: _,
span: _,
}) = result
{
Err(ShellError::NotFound {
span: Span::merge_many(rest.iter().map(|s| s.span)),
})
} else {
result
}
}
}
fn examples(&self) -> Vec<Example> {
vec![
Example {
description: "show help for single command, alias, or module",
example: "help match",
result: None,
},
Example {
description: "show help for single sub-command, alias, or module",
example: "help str join",
result: None,
},
Example {
description: "search for string in command names, descriptions, and search terms",
example: "help --find char",
result: None,
},
]
}
}