https://github.com/untodesu/libvterm
Make your terminal emulator colorful!
https://github.com/untodesu/libvterm
ansi-c ansi-colors ansi-escape-codes c89 lib library terminal vt100
Last synced: 6 months ago
JSON representation
Make your terminal emulator colorful!
- Host: GitHub
- URL: https://github.com/untodesu/libvterm
- Owner: untodesu
- License: bsd-2-clause
- Created: 2021-12-17T10:36:58.000Z (almost 4 years ago)
- Default Branch: master
- Last Pushed: 2022-01-17T18:00:48.000Z (over 3 years ago)
- Last Synced: 2025-02-02T17:42:53.248Z (8 months ago)
- Topics: ansi-c, ansi-colors, ansi-escape-codes, c89, lib, library, terminal, vt100
- Language: C
- Homepage:
- Size: 37.1 KB
- Stars: 7
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# libvterm
> Make your terminal emulator colorful!
LibVTerm is an embeddable ANSI C89 (C90) library for parsing ANSI escape sequences.
It is constructed in such way it requires only `ctype.h`, `string.h`, `stddef.h` and at least a malloc-styled allocation API.
## Getting started
The library should be capable of compiling on virtually any C89-compliant C compiler so the repo doesn't contain any build scripts - you do it yourself!
The way library communicates with the outer world is callbacks: libvterm has about 8 of them and 2 are required.
#### System requirements
1. A reliable `void *malloc(size_t)`-ish function (libvterm doesn't check for `NULL` pointers upon allocation).
2. A reliable `void free(void *)`-ish function.
#### Callback descriptions
1. `mem_alloc` - allocate a block of N bytes. Required.
2. `mem_free` - free a previously allocated block. Required.
3. `misc_sequence` - allows parsing custom escape sequences specific for certain implementations.
4. `set_cursor` - updates the cursor position.
5. `mode_change` - implementation-specific actions upon video mode changes.
6. `draw_cell` - put a single cell to the screen.
7. `response` - write a byte back as a terminal response.
8. `ascii` - handle miscellaneous ASCII escape characters.
## Minimal example
~~This is taken from [Demos](https://github.com/undnull/demos) (from about [here](https://github.com/undnull/demos/blob/master/arch/x86_64/boot/tmvga.c))~~
The above source file doesn't exist anymore :)
#### Code
```c
static void on_misc_sequence(
const struct vterm *vt, int chr)
{
/* TMVGA driver supports DEC VT-220 "show/hide cursor" private
* sequences because VGA CRTC can show and hide the hardware cursor */
/* Some x86 port i/o stuff is going on here... */
}
static void on_set_cursor(
const struct vterm *vt,
const struct vterm_cursor *cursor)
{
/* Again, TMVGA supports moving the cursor because VGA CRTC
* has hardware cursor support so we don't need to emulate it. */
/* Some more x86 port i/o stuff is going on here... */
}
static void on_draw_cell(
const struct vterm *vt, int chr,
unsigned int x, unsigned int y,
const struct vterm_attrib *attrib)
{
/* The colors in VGA text mode slightly differ from the colors
* defined by the ANSI standard so this function remaps the colors
* depending on the flags (like INVERT or BRIGHT) and writes the
* character directly to the video memory. It also would be worth
* noting that not all attributes may be supported by the implementation
* so you are free to check for whatever you want to check for here. */
/* Some x86 and VGA trickery is going on here... */
}
static struct vterm vt = { 0 };
int init_tmvga(/* ... some bootloader stuff ... */)
{
struct vterm_callbacks callbacks;
/* some unrelated code */
/* Here we send the required memory allocation functions
* to the library. Without them vterm_init will fail. */
callbacks.mem_alloc = &kmalloc;
callbacks.mem_free = &kmfree;
/* These are not required by the library but without, say
* draw_cell callback we won't be able to see anything! */
callbacks.misc_sequence = &on_misc_sequence;
callbacks.set_cursor = &on_set_cursor;
callbacks.draw_cell = &on_draw_cell;
vterm_init(&vt, &callbacks, NULL);
/* some unrelated code */
}
```
#### Action!
