Duktape is an embeddable Javascript engine, with a focus on portability and compact footprint.
Duktape is easy to integrate into a C/C++ project: add duktape.c
,
duktape.h
, and duk_config.h
to your build, and use the
Duktape API to call Ecmascript functions from C code and vice versa.
x86 default | x86 lowmem | x86 full lowmem | |
Code | 170kB | 150kB | 200kB |
Startup RAM | 68kB | 35kB | 2.3kB |
See GCC options for minimizing code footprint. Full lowmem uses "pointer compression" and ROM-based strings/objects. ROM-based strings/objects can also be used without other low memory options.
#duktape
on chat.freenode.net
(webchat)See: Projects using Duktape.
If you're using Duktape in your project, send an e-mail or open a GitHub issue to be added to the list.
There are multiple Javascript engines targeting similar use cases as Duktape, at least:
Also see List of ECMAScript engines.
(See Getting started for a more detailed introduction.)
Add Duktape C source and header to your build. Any build system can be used. The distributable contains an example Makefile for reference. In the simplest case:
$ gcc -std=c99 -otest test.c duktape.c -lm
$ ./test
1+2=3
To customize Duktape configuration,
here to disable Ecmascript 6 Proxy
object support:
$ python2 duktape-2.0.0/tools/configure.py --output-directory src-duktape \ -UDUK_USE_ES6_PROXY $ ls src-duktape/ duk_config.h duk_source_meta.json duktape.c duktape.h $ gcc -std=c99 -otest -Isrc-duktape \ test.c src-duktape/duktape.c -lm $ ./test 1+2=3
Initialize and use Duktape somewhere in your program:
/* test.c */ #include <stdio.h> #include "duktape.h" int main(int argc, char *argv[]) { duk_context *ctx = duk_create_heap_default(); duk_eval_string(ctx, "1+2"); printf("1+2=%d\n", (int) duk_get_int(ctx, -1)); duk_destroy_heap(ctx); return 0; }
To call a C function from Ecmascript code, first declare your C functions:
/* Being an embeddable engine, Duktape doesn't provide I/O * bindings by default. Here's a simple one argument print() * function. */ static duk_ret_t native_print(duk_context *ctx) { printf("%s\n", duk_to_string(ctx, 0)); return 0; /* no return value (= undefined) */ } /* Adder: add argument values. */ static duk_ret_t native_adder(duk_context *ctx) { int i; int n = duk_get_top(ctx); /* #args */ double res = 0.0; for (i = 0; i < n; i++) { res += duk_to_number(ctx, i); } duk_push_number(ctx, res); return 1; /* one return value */ }
Register your functions e.g. into the global object:
duk_push_c_function(ctx, native_print, 1 /*nargs*/); duk_put_global_string(ctx, "print"); duk_push_c_function(ctx, native_adder, DUK_VARARGS); duk_put_global_string(ctx, "adder");
You can then call your function from Ecmascript code:
duk_eval_string_noresult(ctx, "print('2+3=' + adder(2, 3));");