BTUI - Bruce's Text User Interface Library

BTUI is a minimal, embeddable single header file alternative to bloatware like ncurses. BTUI aims to be under 1/1,000th the size of ncurses, while also providing a more usable and modern API.

Language Bindings

BTUI comes with bindings for C and Lua, with plans to add Python bindings.

C API

BTUI has the following C function definitions, as well as definitions for some constants, including terminal escape values and keycodes.

btui_t* btui_enable(void);
void btui_disable(btui_t *bt);
int btui_getkey(btui_t *bt, int *mouse_x, int *mouse_y);
int btui_move_cursor(btui_t *bt, int x, int y);
char *btui_keyname(int key, char *buf);
int btui_keynamed(const char *name);
int btui_set_attributes(btui_t *bt, unsigned long attrs);
int btui_set_fg_rgb(btui_t *bt, unsigned char r, unsigned char g, unsigned char b);
int btui_set_bg_rgb(btui_t *bt, unsigned char r, unsigned char g, unsigned char b);
int btui_set_fg_hex(btui_t *bt, int hex);
int btui_set_bg_hex(btui_t *bt, int hex);
#define btui_printf(bt, ...) fprintf((bt)->out, __VA_ARGS__)
#define btui_puts(bt, s) fputs(s, (bt)->out)
#define btui_flush(bt) fflush((bt)->out)
#define btui_clear(bt) fputs("\033[2J", (bt)->out)
#define btui_clear_below(bt) fputs("\033[J", (bt)->out)
#define btui_clear_above(bt) fputs("\033[1J", (bt)->out)
#define btui_clear_eol(bt) fputs("\033[K", (bt)->out)
#define btui_clear_line(bt) fputs("\033[2K", (bt)->out)

Lua API

The Lua library returns a function that takes one argument: a function that will be called with a BTUI object, which can be used to do TUI actions. Errors will be propagated out of the function, but the terminal will be cleaned up nicely before the error is printed. Here's a simple example program:

local btui = require("btui")

btui(function(bt)
    local key = nil
    local x, y = 0, 0
    while key ~= "q" and key ~= "Ctrl-c" do
        bt:clear()
        bt:move(x, y)
        bt:print("Pressed: ", key)
        if key == "e" then error("ERR MESSAGE") end
        local s = ("Size: (%dx%d)"):format(bt:width(), bt:height())
        bt:move(bt:width()-#s, bt:height()-1)
        bt:print(s)

        local mouse_x, mouse_y
        key, mouse_x, mouse_y = bt:getkey()
        if mouse_x then x, y = mouse_x, mouse_y end
    end
    if key == "Ctrl-c" then
        error("Interrupt received!")
    end
end)