Using C functions and libraries in your shell code!!

[sc0ttman]

https://github.com/taviso/ctypes.sh

A foreign function interface for bash.

This could be really useful

You can use this to call C functions from with your shell code - making your shell scripts able to perform very fast C functions

This could be used for a number of things:

- write programs in shell script that use real GTK interfaces (not only gtkdialog)
- call C functions to do dependency management in PPM
- embedded webkit in gtk using shell script
- lots more.. See all examples here - https://github.com/taviso/ctypes.sh/tree/master/test

Here's an example which creates a GTK frontend for a shell script:

Code: Select all

#!/bin/bash

# This is a port of the GTK+3 Hello World to bash.
#
# https://developer.gnome.org/gtk3/stable/gtk-getting-started.html
source ctypes.sh

# declare some numeric constants used by GTK+
declare -ri GTK_ORIENTATION_HORIZONTAL=0
declare -ri G_APPLICATION_FLAGS_NONE=0
declare -ri G_CONNECT_AFTER=$((1 << 0))
declare -ri G_CONNECT_SWAPPED=$((1 << 1))

# void print_hello(GtkApplication *app, gpointer user_data)
function print_hello ()
{
    echo "Hello World"
}

# void activate(GtkApplication *app, gpointer user_data)
function activate ()
{
    local app=$2
    local user_data=$3
    local window
    local button
    local button_box

    dlsym -n gtk_widget_destroy gtk_widget_destroy

    dlcall -n window -r pointer gtk_application_window_new $app
    dlcall gtk_window_set_title $window "Window"
    dlcall gtk_window_set_default_size $window 200 200

    dlcall -n button_box -r pointer gtk_button_box_new $GTK_ORIENTATION_HORIZONTAL
    dlcall gtk_container_add $window $button_box

    dlcall -n button -r pointer gtk_button_new_with_label "Hello World"
    dlcall g_signal_connect_data $button "clicked" $print_hello $NULL $NULL 0
    dlcall g_signal_connect_data $button "clicked" $gtk_widget_destroy $window $NULL $G_CONNECT_SWAPPED
    dlcall gtk_container_add $button_box $button

    dlcall gtk_widget_show_all $window
}

declare app     # GtkApplication *app
declare status  # int status

# Generate function pointers that can be called from native code.
callback -n print_hello print_hello void pointer pointer
callback -n activate activate void pointer pointer

# Prevent threading issues.
taskset -p 1 $$ &> /dev/null

# Make libgtk-3 symbols available
dlopen libgtk-3.so.0

dlcall -n app -r pointer gtk_application_new "org.gtk.example" $G_APPLICATION_FLAGS_NONE
dlcall -r ulong g_signal_connect_data $app "activate" $activate $NULL $NULL 0
dlcall -n status -r int g_application_run $app 0 $NULL
dlcall g_object_unref $app

exit ${status##*:}

You should consider the above example similar to our own GtkDialog scripts, except that we're accessing the full GTK interface, not the fairly limited/broken implementation of it that is GtkDialog.

---

ctypes.sh makes it possible to use GTK+ natively in your shell scripts, or write a high-performance http daemon.

A project which uses it: https://github.com/cemeyer/httpd.sh

[step]

Nice find, thanks.

[wiak]

Yes, nice. And MIT license. Might take a look at its inners sometime.

[rockedge]

I will be experimenting with this capability immediately!!