nu_command/platform/
clear.rs

1use crossterm::{
2    QueueableCommand,
3    cursor::MoveTo,
4    terminal::{Clear as ClearCommand, ClearType},
5};
6use nu_engine::command_prelude::*;
7use nu_protocol::shell_error::io::IoError;
8
9use std::io::Write;
10
11#[derive(Clone)]
12pub struct Clear;
13
14impl Command for Clear {
15    fn name(&self) -> &str {
16        "clear"
17    }
18
19    fn description(&self) -> &str {
20        "Clear the terminal screen."
21    }
22
23    fn extra_description(&self) -> &str {
24        "By default clears the current screen and the off-screen scrollback buffer."
25    }
26
27    fn search_terms(&self) -> Vec<&str> {
28        vec!["cls"]
29    }
30
31    fn signature(&self) -> Signature {
32        Signature::build("clear")
33            .category(Category::Platform)
34            .input_output_types(vec![(Type::Nothing, Type::Nothing)])
35            .switch(
36                "keep-scrollback",
37                "Do not clear the scrollback history.",
38                Some('k'),
39            )
40    }
41
42    fn run(
43        &self,
44        engine_state: &EngineState,
45        stack: &mut Stack,
46        call: &Call,
47        _input: PipelineData,
48    ) -> Result<PipelineData, ShellError> {
49        let from_io_error = IoError::factory(call.head, None);
50        match call.has_flag(engine_state, stack, "keep-scrollback")? {
51            true => {
52                std::io::stdout()
53                    .queue(MoveTo(0, 0))
54                    .map_err(&from_io_error)?
55                    .queue(ClearCommand(ClearType::All))
56                    .map_err(&from_io_error)?
57                    .flush()
58                    .map_err(&from_io_error)?;
59            }
60            _ => {
61                std::io::stdout()
62                    .queue(MoveTo(0, 0))
63                    .map_err(&from_io_error)?
64                    .queue(ClearCommand(ClearType::All))
65                    .map_err(&from_io_error)?
66                    .queue(ClearCommand(ClearType::Purge))
67                    .map_err(&from_io_error)?
68                    .flush()
69                    .map_err(&from_io_error)?;
70            }
71        };
72
73        Ok(PipelineData::empty())
74    }
75
76    fn examples(&self) -> Vec<Example<'_>> {
77        vec![
78            Example {
79                description: "Clear the terminal.",
80                example: "clear",
81                result: None,
82            },
83            Example {
84                description: "Clear the terminal but not its scrollback history.",
85                example: "clear --keep-scrollback",
86                result: None,
87            },
88        ]
89    }
90}
nu_command/platform/clear.rs

nu_command/platform/
clear.rs
