feat: Add receive command

Adds a command to receive a single message from a queue.
This commit is contained in:
Vincent Ambo 2017-10-20 16:29:53 +02:00 committed by Karl Erik Asbjørnsen
parent 23ac0eef87
commit a023e05474

View file

@ -4,11 +4,10 @@ extern crate posix_mq;
use clap::{App, SubCommand, Arg, ArgMatches, AppSettings};
use posix_mq::{Name, Queue};
use std::fs::{read_dir, File};
use std::io::Read;
use std::io::{self, Read, Write};
use std::process::exit;
fn run_ls() {
let mqueues = read_dir("/dev/mqueue")
.expect("Could not read message queues");
@ -50,25 +49,47 @@ fn run_create(cmd: &ArgMatches) {
match queue {
Ok(_) => println!("Queue created successfully"),
Err(e) => {
println!("Could not create queue: {}", e);
writeln!(io::stderr(), "Could not create queue: {}", e).ok();
exit(1);
},
};
}
fn run_receive(queue_name: &str) {
let name = Name::new(queue_name).expect("Invalid queue name");
let queue = Queue::open(name).expect("Could not open queue");
let message = match queue.receive() {
Ok(msg) => msg,
Err(e) => {
writeln!(io::stderr(), "Failed to receive message: {}", e).ok();
exit(1);
}
};
// Attempt to write the message out as a string, but write out raw bytes if it turns out to not
// be UTF-8 encoded data.
match String::from_utf8(message.data.clone()) {
Ok(string) => println!("{}", string),
Err(_) => {
writeln!(io::stderr(), "Message not UTF-8 encoded!").ok();
io::stdout().write(message.data.as_ref()).ok();
}
};
}
fn main() {
let ls = SubCommand::with_name("ls").about("list message queues");
let queue_arg = Arg::with_name("queue").required(true).takes_value(true);
let inspect = SubCommand::with_name("inspect")
.about("inspect details about a queue")
.arg(Arg::with_name("queue")
.required(true)
.takes_value(true));
.arg(&queue_arg);
let create = SubCommand::with_name("create")
.about("Create a new queue")
.arg(Arg::with_name("queue")
.required(true)
.takes_value(true))
.arg(&queue_arg)
.arg(Arg::with_name("max-size")
.help("maximum message size (in kB)")
.long("max-size")
@ -80,6 +101,10 @@ fn main() {
.required(true)
.takes_value(true));
let receive = SubCommand::with_name("receive")
.about("Receive a message from a queue")
.arg(&queue_arg);
let matches = App::new("mq")
.setting(AppSettings::SubcommandRequiredElseHelp)
@ -88,12 +113,14 @@ fn main() {
.subcommand(ls)
.subcommand(inspect)
.subcommand(create)
.subcommand(receive)
.get_matches();
match matches.subcommand() {
("ls", _) => run_ls(),
("inspect", Some(cmd)) => run_inspect(cmd.value_of("queue").unwrap()),
("create", Some(cmd)) => run_create(cmd),
("receive", Some(cmd)) => run_receive(cmd.value_of("queue").unwrap()),
_ => unimplemented!(),
}
}