term/
lib.rs

1// Copyright 2013-2019 The Rust Project Developers. See the COPYRIGHT
2// file at the top-level directory of this distribution and at
3// http://rust-lang.org/COPYRIGHT.
4//
5// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8// option. This file may not be copied, modified, or distributed
9// except according to those terms.
10
11//! Terminal formatting library.
12//!
13//! This crate provides the `Terminal` trait, which abstracts over an [ANSI
14//! Terminal][ansi] to provide color printing, among other things. There are two
15//! implementations, the `TerminfoTerminal`, which uses control characters from
16//! a [terminfo][ti] database, and `WinConsole`, which uses the [Win32 Console
17//! API][win].
18//!
19//! # Usage
20//!
21//! This crate is [on crates.io](https://crates.io/crates/term) and can be
22//! used by adding `term` to the dependencies in your project's `Cargo.toml`.
23//!
24//! ```toml
25//! [dependencies]
26//!
27//! term = "*"
28//! ```
29//!
30//! and this to your crate root:
31//!
32//! ```rust
33//! extern crate term;
34//! ```
35//!
36//! # Examples
37//!
38//! ```no_run
39//! extern crate term;
40//! use std::io::prelude::*;
41//!
42//! fn main() {
43//!     let mut t = term::stdout().unwrap();
44//!
45//!     t.fg(term::color::GREEN).unwrap();
46//!     write!(t, "hello, ").unwrap();
47//!
48//!     t.fg(term::color::RED).unwrap();
49//!     writeln!(t, "world!").unwrap();
50//!
51//!     t.reset().unwrap();
52//! }
53//! ```
54//!
55//! [ansi]: https://en.wikipedia.org/wiki/ANSI_escape_code
56//! [win]: http://msdn.microsoft.com/en-us/library/windows/desktop/ms682010%28v=vs.85%29.aspx
57//! [ti]: https://en.wikipedia.org/wiki/Terminfo
58
59#![doc(
60    html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
61    html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
62    html_root_url = "https://stebalien.github.io/doc/term/term/",
63    test(attr(deny(warnings)))
64)]
65#![deny(missing_docs)]
66#![cfg_attr(test, deny(warnings))]
67#![allow(clippy::redundant_field_names)]
68
69use std::io::prelude::*;
70
71pub use crate::terminfo::TerminfoTerminal;
72#[cfg(windows)]
73pub use win::{WinConsole, WinConsoleInfo};
74
75use std::io::{self, Stderr, Stdout};
76
77pub mod terminfo;
78
79#[cfg(windows)]
80mod win;
81
82/// Alias for stdout terminals.
83pub type StdoutTerminal = dyn Terminal<Output = Stdout> + Send;
84/// Alias for stderr terminals.
85pub type StderrTerminal = dyn Terminal<Output = Stderr> + Send;
86
87#[cfg(not(windows))]
88/// Return a Terminal wrapping stdout, or None if a terminal couldn't be
89/// opened.
90pub fn stdout() -> Option<Box<StdoutTerminal>> {
91    TerminfoTerminal::new(io::stdout()).map(|t| Box::new(t) as Box<StdoutTerminal>)
92}
93
94#[cfg(windows)]
95/// Return a Terminal wrapping stdout, or None if a terminal couldn't be
96/// opened.
97pub fn stdout() -> Option<Box<StdoutTerminal>> {
98    TerminfoTerminal::new(io::stdout())
99        .map(|t| Box::new(t) as Box<StdoutTerminal>)
100        .or_else(|| {
101            WinConsole::new(io::stdout())
102                .ok()
103                .map(|t| Box::new(t) as Box<StdoutTerminal>)
104        })
105}
106
107#[cfg(not(windows))]
108/// Return a Terminal wrapping stderr, or None if a terminal couldn't be
109/// opened.
110pub fn stderr() -> Option<Box<StderrTerminal>> {
111    TerminfoTerminal::new(io::stderr()).map(|t| Box::new(t) as Box<StderrTerminal>)
112}
113
114#[cfg(windows)]
115/// Return a Terminal wrapping stderr, or None if a terminal couldn't be
116/// opened.
117pub fn stderr() -> Option<Box<StderrTerminal>> {
118    TerminfoTerminal::new(io::stderr())
119        .map(|t| Box::new(t) as Box<StderrTerminal>)
120        .or_else(|| {
121            WinConsole::new(io::stderr())
122                .ok()
123                .map(|t| Box::new(t) as Box<StderrTerminal>)
124        })
125}
126
127/// Terminal color definitions
128#[allow(missing_docs)]
129pub mod color {
130    /// Number for a terminal color
131    pub type Color = u32;
132
133    pub const BLACK: Color = 0;
134    pub const RED: Color = 1;
135    pub const GREEN: Color = 2;
136    pub const YELLOW: Color = 3;
137    pub const BLUE: Color = 4;
138    pub const MAGENTA: Color = 5;
139    pub const CYAN: Color = 6;
140    pub const WHITE: Color = 7;
141
142    pub const BRIGHT_BLACK: Color = 8;
143    pub const BRIGHT_RED: Color = 9;
144    pub const BRIGHT_GREEN: Color = 10;
145    pub const BRIGHT_YELLOW: Color = 11;
146    pub const BRIGHT_BLUE: Color = 12;
147    pub const BRIGHT_MAGENTA: Color = 13;
148    pub const BRIGHT_CYAN: Color = 14;
149    pub const BRIGHT_WHITE: Color = 15;
150}
151
152/// Terminal attributes for use with term.attr().
153///
154/// Most attributes can only be turned on and must be turned off with term.reset().
155/// The ones that can be turned off explicitly take a boolean value.
156/// Color is also represented as an attribute for convenience.
157#[derive(Debug, PartialEq, Hash, Eq, Copy, Clone)]
158pub enum Attr {
159    /// Bold (or possibly bright) mode
160    Bold,
161    /// Dim mode, also called faint or half-bright. Often not supported
162    Dim,
163    /// Italics mode. Often not supported
164    Italic(bool),
165    /// Underline mode
166    Underline(bool),
167    /// Blink mode
168    Blink,
169    /// Standout mode. Often implemented as Reverse, sometimes coupled with Bold
170    Standout(bool),
171    /// Reverse mode, inverts the foreground and background colors
172    Reverse,
173    /// Secure mode, also called invis mode. Hides the printed text
174    Secure,
175    /// Convenience attribute to set the foreground color
176    ForegroundColor(color::Color),
177    /// Convenience attribute to set the background color
178    BackgroundColor(color::Color),
179}
180
181/// An error arising from interacting with the terminal.
182#[derive(Debug)]
183pub enum Error {
184    /// Indicates an error from any underlying IO
185    Io(io::Error),
186    /// Indicates an error during terminfo parsing
187    TerminfoParsing(terminfo::Error),
188    /// Indicates an error expanding a parameterized string from the terminfo database
189    ParameterizedExpansion(terminfo::parm::Error),
190    /// Indicates that the terminal does not support the requested operation.
191    NotSupported,
192    /// Indicates that the `TERM` environment variable was unset, and thus we were unable to detect
193    /// which terminal we should be using.
194    TermUnset,
195    /// Indicates that we were unable to find a terminfo entry for the requested terminal.
196    TerminfoEntryNotFound,
197    /// Indicates that the cursor could not be moved to the requested position.
198    CursorDestinationInvalid,
199    /// Indicates that the terminal does not support displaying the requested color.
200    ///
201    /// This is like `NotSupported`, but more specific.
202    ColorOutOfRange,
203    #[doc(hidden)]
204    /// Please don't match against this - if you do, we can't promise we won't break your crate
205    /// with a semver-compliant version bump.
206    __Nonexhaustive,
207}
208
209// manually implemented because std::io::Error does not implement Eq/PartialEq
210impl std::cmp::PartialEq for Error {
211    fn eq(&self, other: &Error) -> bool {
212        use crate::Error::*;
213        match *self {
214            Io(_) => false,
215            TerminfoParsing(ref inner1) => match *other {
216                TerminfoParsing(ref inner2) => inner1 == inner2,
217                _ => false,
218            },
219            ParameterizedExpansion(ref inner1) => match *other {
220                ParameterizedExpansion(ref inner2) => inner1 == inner2,
221                _ => false,
222            },
223            NotSupported => match *other {
224                NotSupported => true,
225                _ => false,
226            },
227            TermUnset => match *other {
228                TermUnset => true,
229                _ => false,
230            },
231            TerminfoEntryNotFound => match *other {
232                TerminfoEntryNotFound => true,
233                _ => false,
234            },
235            CursorDestinationInvalid => match *other {
236                CursorDestinationInvalid => true,
237                _ => false,
238            },
239            ColorOutOfRange => match *other {
240                ColorOutOfRange => true,
241                _ => false,
242            },
243            __Nonexhaustive => match *other {
244                __Nonexhaustive => true,
245                _ => false,
246            },
247        }
248    }
249}
250
251/// The canonical `Result` type using this crate's Error type.
252pub type Result<T> = std::result::Result<T, Error>;
253
254impl std::fmt::Display for Error {
255    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
256        use crate::Error::*;
257        match *self {
258            Io(ref io) => io.fmt(f),
259            TerminfoParsing(ref e) => e.fmt(f),
260            ParameterizedExpansion(ref e) => e.fmt(f),
261            NotSupported => f.write_str("operation not supported by the terminal"),
262            TermUnset => {
263                f.write_str("TERM environment variable unset, unable to detect a terminal")
264            }
265            TerminfoEntryNotFound => {
266                f.write_str("could not find a terminfo entry for this terminal")
267            }
268            CursorDestinationInvalid => f.write_str("could not move cursor to requested position"),
269            ColorOutOfRange => f.write_str("color not supported by the terminal"),
270            __Nonexhaustive => f.write_str("placeholder variant that shouldn't be used"),
271        }
272    }
273}
274
275impl std::error::Error for Error {
276    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
277        match *self {
278            Error::Io(ref io) => Some(io),
279            Error::TerminfoParsing(ref e) => Some(e),
280            Error::ParameterizedExpansion(ref e) => Some(e),
281            _ => None,
282        }
283    }
284}
285
286impl From<Error> for io::Error {
287    fn from(err: Error) -> io::Error {
288        let kind = match err {
289            Error::Io(ref e) => e.kind(),
290            _ => io::ErrorKind::Other,
291        };
292        io::Error::new(kind, err)
293    }
294}
295
296impl std::convert::From<io::Error> for Error {
297    fn from(val: io::Error) -> Self {
298        Error::Io(val)
299    }
300}
301
302impl std::convert::From<terminfo::Error> for Error {
303    fn from(val: terminfo::Error) -> Self {
304        Error::TerminfoParsing(val)
305    }
306}
307
308impl std::convert::From<terminfo::parm::Error> for Error {
309    fn from(val: terminfo::parm::Error) -> Self {
310        Error::ParameterizedExpansion(val)
311    }
312}
313
314/// A terminal with similar capabilities to an ANSI Terminal
315/// (foreground/background colors etc).
316pub trait Terminal: Write {
317    /// The terminal's output writer type.
318    type Output: Write;
319
320    /// Sets the foreground color to the given color.
321    ///
322    /// If the color is a bright color, but the terminal only supports 8 colors,
323    /// the corresponding normal color will be used instead.
324    ///
325    /// Returns `Ok(())` if the color change code was sent to the terminal, or `Err(e)` if there
326    /// was an error.
327    fn fg(&mut self, color: color::Color) -> Result<()>;
328
329    /// Sets the background color to the given color.
330    ///
331    /// If the color is a bright color, but the terminal only supports 8 colors,
332    /// the corresponding normal color will be used instead.
333    ///
334    /// Returns `Ok(())` if the color change code was sent to the terminal, or `Err(e)` if there
335    /// was an error.
336    fn bg(&mut self, color: color::Color) -> Result<()>;
337
338    /// Sets the given terminal attribute, if supported.  Returns `Ok(())` if the attribute is
339    /// supported and was sent to the terminal, or `Err(e)` if there was an error or the attribute
340    /// wasn't supported.
341    fn attr(&mut self, attr: Attr) -> Result<()>;
342
343    /// Returns whether the given terminal attribute is supported.
344    fn supports_attr(&self, attr: Attr) -> bool;
345
346    /// Resets all terminal attributes and colors to their defaults.
347    ///
348    /// Returns `Ok(())` if the reset code was printed, or `Err(e)` if there was an error.
349    ///
350    /// *Note: This does not flush.*
351    ///
352    /// That means the reset command may get buffered so, if you aren't planning on doing anything
353    /// else that might flush stdout's buffer (e.g. writing a line of text), you should flush after
354    /// calling reset.
355    fn reset(&mut self) -> Result<()>;
356
357    /// Returns true if reset is supported.
358    fn supports_reset(&self) -> bool;
359
360    /// Returns true if color is fully supported.
361    ///
362    /// If this function returns `true`, `bg`, `fg`, and `reset` will never
363    /// return `Err(Error::NotSupported)`.
364    fn supports_color(&self) -> bool;
365
366    /// Moves the cursor up one line.
367    ///
368    /// Returns `Ok(())` if the cursor movement code was printed, or `Err(e)` if there was an
369    /// error.
370    fn cursor_up(&mut self) -> Result<()>;
371
372    /// Deletes the text from the cursor location to the end of the line.
373    ///
374    /// Returns `Ok(())` if the deletion code was printed, or `Err(e)` if there was an error.
375    fn delete_line(&mut self) -> Result<()>;
376
377    /// Moves the cursor to the left edge of the current line.
378    ///
379    /// Returns `Ok(true)` if the deletion code was printed, or `Err(e)` if there was an error.
380    fn carriage_return(&mut self) -> Result<()>;
381
382    /// Gets an immutable reference to the stream inside
383    fn get_ref(&self) -> &Self::Output;
384
385    /// Gets a mutable reference to the stream inside
386    fn get_mut(&mut self) -> &mut Self::Output;
387
388    /// Returns the contained stream, destroying the `Terminal`
389    fn into_inner(self) -> Self::Output
390    where
391        Self: Sized;
392}
term/lib.rs

term/
lib.rs
