mirror of
https://github.com/dankamongmen/notcurses.git
synced 2024-11-09 19:10:48 +00:00
301 lines
20 KiB
Markdown
301 lines
20 KiB
Markdown
# Notcurses: blingful TUIs and character graphics
|
|
|
|
**What it is**: a library facilitating complex TUIs on modern terminal
|
|
emulators, supporting vivid colors, multimedia, threads, and Unicode to the
|
|
maximum degree possible. [Things](https://www.youtube.com/watch?v=dcjkezf1ARY) can be done with
|
|
Notcurses that simply can't be done with NCURSES. It is furthermore
|
|
fast as shit. **What it is not**: a source-compatible X/Open Curses implementation, nor a
|
|
replacement for NCURSES on existing systems.
|
|
|
|
<p align="center">
|
|
<a href="https://www.youtube.com/watch?v=dcjkezf1ARY"><img src="https://raw.githubusercontent.com/dankamongmen/notcurses/gh-pages/notcurses-logo.png" alt="setting the standard (hype video)"/></a>
|
|
birthed screaming into this world by <a href="https://nick-black.com/dankwiki/index.php/Hack_on">nick black</a> (<a href="mailto:nickblack@linux.com"><nickblack@linux.com></a>)
|
|
</p>
|
|
|
|
* c++ wrappers by [marek habersack](http://twistedcode.net/blog/) (<grendel@twistedcode.net>)
|
|
* rust wrappers by José Luis Cruz (<joseluis@andamira.net>)
|
|
* python wrappers by igo95862 (<igo95862@yandex.ru>)
|
|
* [zig wrappers](https://github.com/dundalek/notcurses-zig-example) by [Jakub Dundalek](https://dundalek.com/) (<dundalek@gmail.com>)
|
|
|
|
for more information, see [dankwiki](https://nick-black.com/dankwiki/index.php/Notcurses)
|
|
and the [man pages](https://notcurses.com). in addition, there is
|
|
[Doxygen](https://notcurses.com/html/) output. there is a
|
|
[mailing list](https://groups.google.com/forum/#!forum/notcurses) which can be reached
|
|
via notcurses@googlegroups.com. i wrote a coherent
|
|
[guidebook](https://nick-black.com/htp-notcurses.pdf), which is available for
|
|
free download (or [paperback purchase](https://amazon.com/dp/B086PNVNC9)).
|
|
|
|
i've not yet added many documented examples, but [src/poc/](https://github.com/dankamongmen/notcurses/tree/master/src/poc)
|
|
and [src/pocpp/](https://github.com/dankamongmen/notcurses/tree/master/src/pocpp)
|
|
contain many small C and C++ programs respectively. `notcurses-demo` covers
|
|
most of the functionality of Notcurses.
|
|
|
|
**If you're running Notcurses applications in a Docker, please consult
|
|
"[Environment notes](#environment-notes)" below.** If you need Notcurses on
|
|
Ubuntu Focal (20.04 LTS), you can run:
|
|
|
|
```sh
|
|
sudo add-apt-repository ppa:dankamongmen/notcurses
|
|
sudo apt-get update
|
|
```
|
|
|
|
<a href="https://repology.org/project/notcurses/versions">
|
|
<img src="https://repology.org/badge/vertical-allrepos/notcurses.svg" alt="Packaging status" align="right">
|
|
</a>
|
|
|
|
|
|
|
|
[](https://app.element.io/#/room/#notcursesdev:matrix.org)
|
|
[](https://github.com/sponsors/dankamongmen)
|
|
|
|
[](https://drone.dsscaw.com:4443/dankamongmen/notcurses)
|
|
[](https://github.com/dankamongmen/notcurses/actions/workflows/ubuntu_test.yml)
|
|
|
|
[](https://pypi.org/project/notcurses)
|
|
[](https://crates.io/crates/libnotcurses-sys)
|
|
|
|
## Introduction
|
|
|
|
Notcurses abandons the X/Open Curses API bundled as part of the Single UNIX
|
|
Specification. For some necessary background, consult Thomas E. Dickey's
|
|
superb and authoritative [NCURSES FAQ](https://invisible-island.net/ncurses/ncurses.faq.html#xterm_16MegaColors).
|
|
As such, Notcurses is not a drop-in Curses replacement.
|
|
|
|
Wherever possible, Notcurses makes use of the Terminfo library shipped with
|
|
NCURSES, benefiting greatly from its portability and thoroughness.
|
|
|
|
Notcurses opens up advanced functionality for the interactive user on
|
|
workstations, phones, laptops, and tablets, possibly at the expense of e.g.
|
|
some industrial and retail terminals. Fundamentally, Curses assumes the minimum
|
|
and allows you (with effort) to step up, whereas Notcurses assumes the maximum
|
|
and steps down (by itself) when necessary. The latter approach probably breaks
|
|
on some older hardware, but the former approach results in new software looking
|
|
like old hardware.
|
|
|
|
Why use this non-standard library?
|
|
|
|
* Thread safety, and efficient use in parallel programs, has been a design
|
|
consideration from the beginning.
|
|
|
|
* A more orderly surface than that codified by X/Open: Exported identifiers are
|
|
prefixed to avoid common namespace collisions. Where reasonable,
|
|
`static inline` header-only code is used. This facilitates compiler
|
|
optimizations, and reduces loader time. Notcurses can be built without its
|
|
multimedia functionality, requiring a significantly lesser set of dependencies.
|
|
|
|
* All APIs natively support the Universal Character Set (Unicode). The `nccell`
|
|
API is based around Unicode's [Extended Grapheme Cluster](https://unicode.org/reports/tr29/) concept.
|
|
|
|
* Visual features including images, fonts, video, high-contrast text, sprites,
|
|
and transparent regions. All APIs natively support 24-bit color, quantized
|
|
down as necessary for the terminal.
|
|
|
|
* It's Apache2-licensed in its entirety, as opposed to the
|
|
[drama in several acts](https://invisible-island.net/ncurses/ncurses-license.html)
|
|
that is the NCURSES license (the latter is [summarized](https://invisible-island.net/ncurses/ncurses-license.html#issues_freer)
|
|
as "a restatement of MIT-X11").
|
|
|
|
Much of the above can be had with NCURSES, but they're not what NCURSES was
|
|
*designed* for. On the other hand, if you're targeting industrial or critical
|
|
applications, or wish to benefit from time-tested reliability and
|
|
portability, you should by all means use that fine library.
|
|
|
|
## Requirements
|
|
|
|
Minimum versions generally indicate the oldest version I've tested with; it
|
|
may well be possible to use still older versions. Let me know of any successes!
|
|
|
|
* (build) CMake 3.14.0+ and a C11 compiler
|
|
* (OPTIONAL) (OpenImageIO, testing, C++ bindings): A C++17 compiler
|
|
* (build+runtime) From [NCURSES](https://invisible-island.net/ncurses/announce.html): terminfo 6.1+
|
|
* (build+runtime) GNU [libunistring](https://www.gnu.org/software/libunistring/) 0.9.10+
|
|
* (OPTIONAL) (build+runtime) GNU [Readline](https://www.gnu.org/software/readline/) 8.0+
|
|
* (OPTIONAL) (build+runtime) From QR-Code-generator: [libqrcodegen](https://github.com/nayuki/QR-Code-generator) 1.5.0+
|
|
* (OPTIONAL) (build+runtime) From [FFmpeg](https://www.ffmpeg.org/): libswscale 5.0+, libavformat 57.0+, libavutil 56.0+
|
|
* (OPTIONAL) (build+runtime) [OpenImageIO](https://github.com/OpenImageIO/oiio) 2.15.0+, requires C++
|
|
* (OPTIONAL) (testing) [Doctest](https://github.com/onqtam/doctest) 2.3.5+
|
|
* (OPTIONAL) (documentation) [pandoc](https://pandoc.org/index.html) 1.19.2+
|
|
* (OPTIONAL) (python bindings): Python 3.7+, [CFFI](https://pypi.org/project/cffi/) 1.13.2+, [pypandoc](https://pypi.org/project/pypandoc/) 1.5+
|
|
* (OPTIONAL) (rust bindings): rust 1.47.0+, [bindgen](https://crates.io/crates/bindgen) 0.55.1+, pkg-config 0.3.18+, cty 0.2.1+
|
|
* (runtime) Linux 5.3+, FreeBSD 11+, or DragonFly BSD 5.9+
|
|
|
|
[Here's more information](INSTALL.md) on building and installation.
|
|
|
|
## Included tools
|
|
|
|
Eight binaries are installed as part of Notcurses:
|
|
* `ncls`: an `ls` that displays multimedia in the terminal
|
|
* `ncneofetch`: a [neofetch](https://github.com/dylanaraps/neofetch) ripoff
|
|
* `ncplayer`: renders visual media (images/videos)
|
|
* `nctetris`: a tetris clone
|
|
* `notcurses-demo`: some demonstration code
|
|
* `notcurses-info`: detect and print terminal capabilities/diagnostics
|
|
* `notcurses-input`: decode and print keypresses
|
|
* `notcurses-tester`: unit testing
|
|
|
|
To run `notcurses-demo` from a checkout, provide the `data` directory via
|
|
the `-p` argument. Demos requiring data files will otherwise abort. The base
|
|
delay used in `notcurses-demo` can be changed with `-d`, accepting a
|
|
floating-point multiplier. Values less than 1 will speed up the demo, while
|
|
values greater than 1 will slow it down.
|
|
|
|
`notcurses-tester` likewise requires that `data`, populated with the necessary
|
|
data files, be specified with `-p`. It can be run by itself, or via `make test`.
|
|
|
|
## Documentation
|
|
|
|
With `-DUSE_PANDOC=on` (the default), a full set of man pages and XHTML
|
|
will be built from `doc/man`. The following Markdown documentation is included
|
|
directly:
|
|
|
|
* Per-release [News](NEWS.md) for packagers, developers, and users.
|
|
* The `TERM` environment variable and [various terminal emulators](TERMINALS.md).
|
|
* Notes on [contributing](doc/CONTRIBUTING.md) and [hacking](doc/HACKING.md).
|
|
* There's a semi-complete [reference guide](USAGE.md).
|
|
* A list of [other TUI libraries](doc/OTHERS.md).
|
|
* Abbreviated [history](doc/HISTORY.md) and thanks.
|
|
* [Differences from](doc/CURSES.md) Curses and adapting Curses programs.
|
|
|
|
If you (understandably) want to avoid the large Pandoc stack, but still enjoy
|
|
manual page goodness, I publish a tarball with generated man/XHTML along with
|
|
each release. Download it, and install the contents as you deem fit.
|
|
|
|
## Environment notes
|
|
|
|
* If your `TERM` variable is wrong, or that terminfo definition is out-of-date,
|
|
you're going to have a very bad time. Use *only* `TERM` values appropriate
|
|
for your terminal. If this variable is undefined, or Notcurses can't load the
|
|
specified Terminfo entry, it will refuse to start, and you will
|
|
[not be going to space today](https://xkcd.com/1133/).
|
|
|
|
* Ensure your `LANG` environment variable is set to a UTF8-encoded locale, and
|
|
that this locale has been generated. This usually means
|
|
`"[language]_[Countrycode].UTF-8"`, i.e. `en_US.UTF-8`. The first part
|
|
(`en_US`) ought exist as a directory or symlink in `/usr/share/locales`.
|
|
This usually requires editing `/etc/locale.gen` and running `locale-gen`.
|
|
On Debian systems, this can be accomplished with `dpkg-reconfigure locales`,
|
|
and enabling the desired locale. The default locale is stored somewhere like
|
|
`/etc/default/locale`.
|
|
|
|
* If your terminal has an option about default interpretation of "ambiguous-width
|
|
characters" (this is actually a technical term from Unicode), ensure it is
|
|
set to **Wide**, not narrow (if that doesn't work, ensure it is set to
|
|
**Narrow**, heh).
|
|
|
|
* If your terminal supports 3x8bit RGB color via `setaf` and `setbf` (most modern
|
|
terminals), but doesn't export the `rgb` terminfo capability, you can export
|
|
the `COLORTERM` environment variable as `truecolor` or `24bit`. Note that some
|
|
terminals accept a 24-bit specification, but map it down to fewer colors.
|
|
RGB is enabled whenever [Foot, Contour, WezTerm, or Kitty](TERMINALS.md) is identified.
|
|
|
|
### Fonts
|
|
|
|
Fonts end up being a whole thing, little of which is pleasant. I'll write this
|
|
up someday **FIXME**.
|
|
|
|
It is worth knowing that several terminals draw the block characters directly,
|
|
rather than loading them from a font. This is generally desirable. To inspect
|
|
your environment's rendering of drawing characters, run `notcurses-info`.
|
|
|
|
## FAQs
|
|
|
|
If things break or seem otherwise lackluster, **please** consult the
|
|
[Environment Notes](#environment_notes) section! You **need** to have a correct
|
|
`TERM` and `LANG` definition, and probably want `COLORTERM`.
|
|
|
|
* **Q:** The demo fails in the middle of `intro`. **A:** Check that your `TERM`
|
|
value is correct for your terminal. `intro` does a palette fade, which is prone
|
|
to breaking under incorrect `TERM` values. If you're not using `xterm`, your
|
|
`TERM` should not be `xterm`!
|
|
|
|
* **Q:** Can I have Notcurses without this huge multimedia stack? **A:** Yes! Build with `-DUSE_MULTIMEDIA=none`.
|
|
|
|
* **Q:** Can I build this individual Notcurses program without aforementioned multimedia stack? **A:** Again yes! Use `notcurses_core_init()` or `ncdirect_core_init()` in place of `notcurses_init()`/`ncdirect_init()`, and link with `-lnotcurses-core`. Your application will likely start a few milliseconds faster; more importantly, it will link against minimal Notcurses installations.
|
|
|
|
* **Q:** Notcurses looks like absolute crap in `screen`. **A:** `screen` doesn't support RGB colors (at least as of 4.08.00); if you have `COLORTERM` defined, you'll have a bad time. If you have a `screen` that was compiled with `--enable-colors256`, try exporting `TERM=screen-256color` as opposed to `TERM=screen`.
|
|
|
|
* **Q:** Notcurses looks like absolute crap in `mosh`. **A**: Yeah it sure does. I'm not yet sure what's up.
|
|
|
|
* **Q:** Why didn't you just render everything to Sixel? **A:** That's not a TUI; it's a slow and inflexible GUI. Many terminal emulators don't support Sixel. Sixel doesn't work well with mouse selection. Sixel has a limited color palette. With that said, both Sixel and the Kitty bitmap protocol are well-supported.
|
|
|
|
* **Q:** I'm not seeing `NCKEY_RESIZE` until I press some other key. **A:** You've almost certainly failed to mask `SIGWINCH` in some thread, and that thread is receiving the signal instead of the thread which called `notcurses_getc_blocking()`. As a result, the `poll()` is not interrupted. Call `pthread_sigmask()` before spawning any threads.
|
|
|
|
* **Q:** Using the C++ wrapper, how can I ensure that the `NotCurses` destructor is run when I return from `main()`? **A:** As noted in the [C++ FAQ](https://isocpp.org/wiki/faq/dtors#artificial-block-to-control-lifetimes), wrap it in an artificial scope (this assumes your `NotCurses` is scoped to `main()`).
|
|
|
|
* **Q:** How do I hide a plane I want to make visible later? **A:** In order of least to most performant: move it offscreen using `ncplane_move_yx()`, move it underneath an opaque plane with `ncplane_move_below()`, or move it off-pile with `ncplane_reparent()`.
|
|
|
|
* **Q:** Why isn't there an `ncplane_box_yx()`? Do you hate orthogonality, you dullard? **A:** `ncplane_box()` and friends already have far too many arguments, you monster.
|
|
|
|
* **Q:** Why doesn't Notcurses support 10- or 16-bit color? **A:** Notcurses supports 24 bits of color, spread across three eight-bit channels. You presumably mean 10-bit-per-channel color. I needed those six bits for other things. When terminals support it, Notcurses might support it.
|
|
|
|
* **Q:** The name is dumb. **A:** That's not a question?
|
|
|
|
* **Q:** I'm not finding qrcodegen on BSD, despite having installed `graphics/qr-code-generator`. **A:** Try `cmake -DCMAKE_REQUIRED_INCLUDES=/usr/local/include`. This is passed by `bsd.port.mk`.
|
|
|
|
* **Q:** Do you support [musl](https://musl.libc.org/)? **A:** I try to! You'll need at least 1.20.
|
|
|
|
* **Q:** I only seem to blit in ASCII, and/or can't emit Unicode beyond ASCII in general. **A:** Your `LANG` environment variable is underdefined or incorrectly defined, or the necessary locale is not present on your machine (it is also possible that you explicitly supplied `NCOPTION_INHIBIT_SETLOCALE`, but never called `setlocale(3)`, in which case don't do that).
|
|
|
|
* **Q:** I pretty much always need an `ncplane` when using a `nccell`. Why doesn't the latter hold a pointer to the former? **A:** Besides the massive redundancy this would entail, `nccell` needs to remain as small as possible, and you almost always have the `ncplane` handy if you've got a reference to a valid `nccell` anyway.
|
|
|
|
* **Q:** I ran `notcurses-demo`, but my table numbers don't match the Notcurses banner numbers, you charlatan. **A:** `notcurses-demo` renders several frames beyond the actual demos.
|
|
|
|
* **Q:** When my program exits, I don't have a cursor, or text is invisible, or colors are weird, <i>ad nauseam</i>. **A:** Ensure you're calling `notcurses_stop()`/`ncdirect_stop()` on all exit paths, including fatal signals (note that, by default, Notcurses installs handlers for most fatal signals to do exactly this).
|
|
|
|
* **Q:** How can I use Direct Mode in conjunction with libreadline? **A:** Pass `NCDIRECT_OPTION_CBREAK` to `ncdirect_init()`, and ensure you do not pass `NCDIRECT_OPTION_NO_READLINE`. If you'd like, set `rl_readline_name` and `rl_attempted_completion_function` prior to calling `ncdirect_init()`. With that said, consider using a Notcurses `ncreader`.
|
|
|
|
* **Q:** Will there ever be Java wrappers? **A:** I should hope not. If you want a Java solution, try Autumn Lamonte's [Jexer](https://jexer.sourceforge.io/).
|
|
|
|
* **Q:** Given that the glyph channel is initialized as transparent for a plane, shouldn't the foreground and background be initialized as transparent, also? **A:** Probably (they are instead initialized to default opaque). This would change some of the most longstanding behavior of Notcurses, though, so it isn't happening.
|
|
|
|
* **Q:** Why does my right-to-left text appear left-to-right? **A:** Notcurses doesn't honor the BiDi state machine, and in fact forces left-to-right with BiDi codes. Likewise, ultra-wide glyphs will have interesting effects. ﷽!
|
|
|
|
* **Q:** I get linker errors when statically linking. **A:** Are you linking all necessary libraries? Use `pkg-config --static --libs notcurses` (or `--libs notcurses-core`) to discover them.
|
|
|
|
* **Q:** Can I avoid manually exporting `COLORTERM=24bit` everywhere? **A:** Sure. Add `SendEnv COLORTERM` to `.ssh/config`, and `AcceptEnv COLORTERM` to `sshd_config` on the remote server. Yes, this will probably require root on the remote server. Don't blame me, man; I didn't do it.
|
|
|
|
* **Q:** How about *arbitrary image manipulation here* functionality? **A:** I'm not going to beat ImageMagick et al. on image manipulation, but you can load an `ncvisual` from RGBA memory using `ncvisual_from_rgba()`.
|
|
|
|
* **Q:** My program locks up during initialization. **A**: Notcurses interrogates the terminal. If the terminal doesn't reply to standard interrogations, file a Notcurses bug, send upstream a patch, or use a different terminal. No known terminal emulators exhibit this behavior.
|
|
|
|
* **Q:** How do I mix Rendered and Direct mode? **A:** You really don't want to. You can stream a subprocess to a plane with the `ncsubproc` widget.
|
|
|
|
## Useful links
|
|
|
|
* [BiDi in Terminal Emulators](https://terminal-wg.pages.freedesktop.org/bidi/)
|
|
* [The Xterm FAQ](https://invisible-island.net/xterm/xterm.faq.html)
|
|
* [XTerm Control Sequences](https://invisible-island.net/xterm/ctlseqs/ctlseqs.pdf)
|
|
* [The NCURSES FAQ](https://invisible-island.net/ncurses/ncurses.faq.html)
|
|
* [ECMA-35 Character Code Structure and Extension Techniques](https://www.ecma-international.org/publications/standards/Ecma-035.htm) (ISO/IEC 2022)
|
|
* [ECMA-43 8-bit Coded Character Set Structure and Rules](https://www.ecma-international.org/publications/standards/Ecma-043.htm)
|
|
* [ECMA-48 Control Functions for Coded Character Sets](https://www.ecma-international.org/publications/standards/Ecma-048.htm) (ISO/IEC 6429)
|
|
* [Unicode 13.1 Full Emoji List](https://unicode.org/emoji/charts/full-emoji-list.html)
|
|
* [Unicode Standard Annex #29 Text Segmentation](http://www.unicode.org/reports/tr29)
|
|
* [Unicode Standard Annex #15 Normalization Forms](https://unicode.org/reports/tr15/)
|
|
* [mintty tips](https://github.com/mintty/mintty/wiki/Tips)
|
|
* [The TTY demystified](http://www.linusakesson.net/programming/tty/)
|
|
* [Dark Corners of Unicode](https://eev.ee/blog/2015/09/12/dark-corners-of-unicode/)
|
|
* [UTF-8 Decoder Capability and Stress Test](https://www.cl.cam.ac.uk/~mgk25/ucs/examples/UTF-8-test.txt)
|
|
* [Emoji: how do you get from U+1F355 to 🍕?](https://meowni.ca/posts/emoji-emoji-emoji/)
|
|
* [Glyph Hell: An introduction to glyphs, as used and defined in the FreeType engine](http://chanae.walon.org/pub/ttf/ttf_glyphs.htm)
|
|
* My wiki's [Sixel page](https://nick-black.com/dankwiki/index.php?title=Sixel) and Kitty's [extensions](https://sw.kovidgoyal.net/kitty/protocol-extensions.html).
|
|
|
|
### Useful man pages
|
|
* Linux: [console_codes(4)](http://man7.org/linux/man-pages/man4/console_codes.4.html)
|
|
* Linux: [termios(3)](http://man7.org/linux/man-pages/man3/termios.3.html)
|
|
* Linux: [ioctl_tty(2)](http://man7.org/linux/man-pages/man2/ioctl_tty.2.html)
|
|
* Linux: [ioctl_console(2)](http://man7.org/linux/man-pages/man2/ioctl_console.2.html)
|
|
* Portable: [terminfo(5)](http://man7.org/linux/man-pages/man5/terminfo.5.html)
|
|
* Portable: [user_caps(5)](http://man7.org/linux/man-pages/man5/user_caps.5.html)
|
|
|
|
### Grotesque vanity and meaningless metrics
|
|
|
|
[](https://starcharts.herokuapp.com/dankamongmen/notcurses)
|
|
|
|
> “Our fine arts were developed, their types and uses were established, in times
|
|
very different from the present, by men whose power of action upon things was
|
|
insignificant in comparison with ours. But the amazing growth of our
|
|
techniques, the adaptability and precision they have attained, the ideas and
|
|
habits they are creating, make it a certainty that _profound changes are
|
|
impending in the ancient craft of the Beautiful_.” —Paul Valéry
|