Re: How to do IPC using Unix Domain Socket?
On Thursday, 10 October 2019 at 12:30:25 UTC, Hossain Adnan wrote:
Here I have a program that wants to
1. detect whether if it's the only instance
1.1. it does that by trying to create a Unix Domain Socket
and trying to binding it to a specific address.
2. if a duplicate program is not running, establish an UDS
and then listen to the socket.
2.1. if any message comes through that socket, the program
will log the incoming message
2.2. otherwise it should keep listening to the socket
forever
3. if there's a duplicate program it should send a message and
then exit.
Here's what I have:
import std.socket, std.experimental.logger;
immutable string socketAddress = "\0/tmp/com.localserver.myapp";
void main()
{
auto socket = new
std.socket.Socket(std.socket.AddressFamily.UNIX,
std.socket.SocketType.STREAM);
auto addr = new std.socket.UnixAddress(socketAddress);
auto isUnique = () {
bool result;
scope (success)
log("returns: ", result);
try
{
socket.bind(addr);
result = true;
}
catch (std.socket.SocketOSException e)
result = false;
// else throw error
return result;
}();
if (isUnique)
{
log("Unique instance detected. Listening...");
// works upto now
char[] buffer = [];
while (1)
{
socket.listen(0);
socket.receive(buffer);
if (buffer != []) {
log("Received message: ", buffer);
}
buffer = [];
}
}
else
{
log("Duplicate instance detected.");
socket.connect(addr);
import std.stdio;
stdout.write("Enter your message:\t");
socket.send(readln());
log("Message has been sent. Exiting.");
}
}
The documentation does not seem very friendly to those who does
not have any experience in socket programming.
Consulted stackoverflow and came up with this:
import std.socket, std.experimental.logger;
class UDSIPC
{
private:
static immutable string socketAddress =
"\0/tmp/com.localserver.myapp";
static immutable size_t messageBufferSize = 64;
static immutable string socketAddressName =
"\0/tmp/com.localserver.myapp";
Socket socket;
UnixAddress uaddr;
public:
this(in string socketAddressName = socketAddressName)
{
socket = new Socket(AddressFamily.UNIX, SocketType.STREAM);
uaddr = new UnixAddress(socketAddress);
}
bool getUniqueness()
{
bool result;
scope (success)
log("returns: ", result);
try
{
socket.bind(uaddr);
result = true;
}
catch (SocketOSException e)
result = false;
// else throw error
return result;
}
string getMessage()
{
socket.listen(0);
auto receiverSocket = socket.accept();
char[messageBufferSize] buffer;
auto amount = receiverSocket.receive(buffer);
import std.string;
return format!"%s"(buffer[0 .. amount]);
}
void sendMessage(in string message)
{
socket.connect(uaddr);
socket.send(message);
}
}
void main()
{
auto ipc = new UDSIPC();
if (ipc.getUniqueness())
{
while (true)
{
log(ipc.getMessage());
}
}
else
{
import std.stdio, std.string;
ipc.sendMessage(readln().chomp());
}
}
Re: How to do IPC using Unix Domain Socket?
On Thursday, 10 October 2019 at 12:30:25 UTC, Hossain Adnan wrote: Here I have a program that wants to 1. detect whether if it's the only instance 1.1. it does that by trying to create a Unix Domain Socket and trying to binding it to a specific address. [...] If it helps explaining better, similar rust code is here: https://gitlab.com/snippets/1893594
How to do IPC using Unix Domain Socket?
Here I have a program that wants to
1. detect whether if it's the only instance
1.1. it does that by trying to create a Unix Domain Socket
and trying to binding it to a specific address.
2. if a duplicate program is not running, establish an UDS
and then listen to the socket.
2.1. if any message comes through that socket, the program
will log the incoming message
2.2. otherwise it should keep listening to the socket forever
3. if there's a duplicate program it should send a message and
then exit.
Here's what I have:
import std.socket, std.experimental.logger;
immutable string socketAddress = "\0/tmp/com.localserver.myapp";
void main()
{
auto socket = new
std.socket.Socket(std.socket.AddressFamily.UNIX,
std.socket.SocketType.STREAM);
auto addr = new std.socket.UnixAddress(socketAddress);
auto isUnique = () {
bool result;
scope (success)
log("returns: ", result);
try
{
socket.bind(addr);
result = true;
}
catch (std.socket.SocketOSException e)
result = false;
// else throw error
return result;
}();
if (isUnique)
{
log("Unique instance detected. Listening...");
// works upto now
char[] buffer = [];
while (1)
{
socket.listen(0);
socket.receive(buffer);
if (buffer != []) {
log("Received message: ", buffer);
}
buffer = [];
}
}
else
{
log("Duplicate instance detected.");
socket.connect(addr);
import std.stdio;
stdout.write("Enter your message:\t");
socket.send(readln());
log("Message has been sent. Exiting.");
}
}
The documentation does not seem very friendly to those who does
not have any experience in socket programming.
Re: How to use Dbus to detect application uniqueness in D?
On Saturday, 28 September 2019 at 13:37:12 UTC, Kagamin wrote: https://ddbus.dpldocs.info/ddbus.bus.requestName.html It requires a Connection type which I cannot find in the API.
Re: Packaging and Distributing Dlang Applications with GtkD Dependency?
On Wednesday, 25 September 2019 at 11:46:04 UTC, Ron Tarrant wrote: Hi y'all, I've been Googling how to do this, but coming up with nothing definitive. Are there any articles for how to do this for: Linux? For Linux there are 3 new options: 1. Appimages (https://appimage.org/): This is very similar to Window's msi installer. You can host the app installer binary in bintray or in your website. 2. Flatpaks (https://flatpak.org/): Flatpak is quickly becoming more and more popular as it provides higher level customization for desktop applications in Linux. The flatpak API is not trivial but there are tutorials available to use flatpak and meson. A well known Linux application named Tilix (https://github.com/gnunn1/tilix) has a flatpak repo (https://github.com/gnunn1/tilix/tree/master/experimental/flatpak). 3. Snap (https://snapcraft.io/): Backed by Cannonical, snap provides a really easy way to distribute applications in Linux. I personally think Snaps are easier to create although I haven't invested time in distributing an app using snap. DMD, Dub and LDC are also shipped with it. There are tutorials for using all of those three online, but not specific to Dlang. But if you use the Meson build system there are plenty of tutorials available.
How to use Dbus to detect application uniqueness in D?
Hi I need to detect application uniqueness using dbus. I have a
working code in Rust:
fn run_as_unique_instance() {
println!("First instance detected. Doing work...");
loop {}
}
fn run_as_nonunique_instance() {
println!("Another instance is already running. Quiting...");
std::process::exit(0);
}
fn main() {
let session =
dbus::blocking::Connection::new_session().expect("Cannot
setup a new dbus session");
match session.request_name("com.localserver.app.bus", false,
false, false) {
Ok(dbus::blocking::stdintf::org_freedesktop_dbus::RequestNameReply::PrimaryOwner) => {
run_as_unique_instance()
}
Ok(_) => run_as_nonunique_instance(), //
RequestNameReply::InQueue
Err(_) => panic!("Error in session name request."),
}
}
This creates a new session in dbus and then requests name. If the
response is "PrimaryOwner" it means the application is unique.
However I can't find the similar symbols in ddbus.
https://ddbus.dpldocs.info/search-results.html#!session
https://ddbus.dpldocs.info/search-results.html#!Connection
Returns nothing.
