pub fn remove_queue_c(name: &CStr) -> Result<(), Error>Expand description
Delete a posix message queue, without inspecting name or allocating.
This function is on NetBSD necessary to remove queues with names that doesn’t start with a ‘/’.
§Errors
- Queue doesn’t exist (ENOENT) =>
ErrorKind::NotFound - Not permitted to delete the queue (EACCES) =>
ErrorKind::PermissionDenied - Posix message queues are disabled (ENOSYS) =>
ErrorKind::Other - More than one ‘/’ in name (EACCESS) =>
ErrorKind::PermissionDenied - Name is empty (EINVAL) =>
ErrorKind::InvalidInput - Name is invalid (ENOENT, EACCESS or EINVAL) =>
ErrorKind::NotFoundErrorKind::PermissionDeniedorErrorKind::InvalidInput - Name is too long (ENAMETOOLONG) =>
ErrorKind::Other - Possibly other
Examples found in repository?
examples/sort.rs (line 54)
10fn main() {
11 let args = args_os()
12 .skip(1)
13 .map(|osstring| osstring.into_vec() )
14 .collect::<Vec<Vec<u8>>>();
15 if args.is_empty() {
16 return; // nothing to do
17 }
18
19 let mut recv_buf = vec![0; args.iter().map(Vec::len).max().unwrap()];
20
21 let name = CStr::from_bytes_with_nul(b"/sort\0").unwrap();
22
23 // create queue with the necessary permissions and open it
24 let mq = posixmq::OpenOptions::readwrite()
25 .nonblocking() // use WouldBlock to detect that the queue is empty
26 .create_new()
27 .mode(0o000) // only affects future attempts at opening it
28 .capacity(args.len())
29 .max_msg_len(recv_buf.len())
30 .open_c(name)
31 .expect("opening queue failed");
32
33 // write arguments to the queue
34 for arg in args {
35 mq.send(arg.len() as u32, &arg).expect("sending failed");
36 }
37
38 // read until the queue is empty
39 let stdout = stdout();
40 let mut stdout = stdout.lock();
41 loop {
42 match mq.recv(&mut recv_buf) {
43 Err(ref e) if e.kind() == ErrorKind::WouldBlock => break,
44 Err(e) => panic!("receiving failed: {}", e),
45 Ok((_priority, len)) => {
46 stdout.write_all(&recv_buf[..len])
47 .and_then(|()| stdout.write_all(b"\n") )
48 .expect("writing to stdout failed");
49 }
50 }
51 }
52
53 // clean up
54 posixmq::remove_queue_c(name).expect("deleting queue failed")
55}More examples
examples/limits.rs (line 88)
28fn main() {
29 println!("{}:", std::env::consts::OS);
30
31 let mq = posixmq::OpenOptions::readwrite()
32 .create_new()
33 .open("/default_capacities")
34 .expect("Cannot create new posix message queue /default_capacities");
35 posixmq::remove_queue("/default_capacities")
36 .expect("Cannot delete posix message queue /default_capacities");
37
38 let attrs = mq.attributes().expect("Cannot get attributes for queue");
39 println!("default queue capacity: {}", attrs.capacity);
40 println!("default maximum message length: {}", attrs.max_msg_len);
41
42 println!("max message priority: {}", btry(0xff_ff_ff_ff, |priority| {
43 mq.send(priority as u32, b"b")
44 .map(|_| mq.recv(&mut vec![0; attrs.max_msg_len]).unwrap() )
45 .is_ok()
46 }));
47 println!("allows empty messages: {}", mq.send(0, b"").is_ok());
48 drop(mq);
49
50 println!("max queue capacity: {}", btry(1_000_000, |capacity| {
51 posixmq::OpenOptions::readwrite()
52 .capacity(capacity)
53 .max_msg_len(1)
54 .create_new()
55 .open("/max_capacity")
56 .map(|_| posixmq::remove_queue("/max_capacity").unwrap() )
57 .is_ok()
58 }));
59
60 println!("max message length: {}", btry(1_000_000, |length| {
61 posixmq::OpenOptions::readwrite()
62 .max_msg_len(length)
63 .capacity(1)
64 .create_new()
65 .open("/max_length")
66 .map(|_| posixmq::remove_queue("/max_length").unwrap() )
67 .is_ok()
68 }));
69
70 println!("max equal: {}", btry(1_000_000, |equal| {
71 posixmq::OpenOptions::readwrite()
72 .max_msg_len(equal)
73 .capacity(equal)
74 .create_new()
75 .open("/max_equal")
76 .map(|_| posixmq::remove_queue("/max_equal").unwrap() )
77 .is_ok()
78 }));
79
80 println!("allows just \"/\": {}", {
81 let result = posixmq::PosixMq::create("/");
82 let _ = posixmq::remove_queue("/");
83 result.is_ok()
84 });
85 println!("enforces name rules: {}", {
86 let noslash = std::ffi::CStr::from_bytes_with_nul(b"noslash\0").unwrap();
87 let result = posixmq::OpenOptions::readwrite().create().open_c(noslash);
88 let _ = posixmq::remove_queue_c(noslash);
89 result.is_err()
90 });
91}