Implement creation of SysV IPC message queues

This adds the `sysvmq` package which handles SysV IPC message queues.
For consistency the parameter for `permissions` is renamed to `mode`
also for POSIX message queues.

src/main.rs

@@ -2,6 +2,7 @@ use anyhow::Result;
 use clap::{crate_authors, crate_version, AppSettings, Clap};
 
 mod posix;
+mod sysv;
 
 #[derive(Clap, Debug)]
 enum Backend {
@@ -23,6 +24,7 @@ enum PosixCommand {
 
 #[derive(Clap, Debug)]
 enum SysvCommand {
+    Create(sysv::Create),
 }
 
 #[derive(Clap, Debug)]
@@ -65,6 +67,7 @@ fn main() -> Result<()> {
             PosixCommand::Recv(r) => r.run()?,
         },
         Backend::Sysv(s) => match s {
+            SysvCommand::Create(c) => c.run()?,
         },
     }
 

src/posix/create.rs

@@ -9,7 +9,7 @@ use std::fs;
 pub struct Create {
     /// Permissions (octal) to create the queue with
     #[clap(short, long)]
-    permissions: Option<String>,
+    mode: Option<String>,
     /// Maximum number of messages in the queue
     #[clap(short, long)]
     capacity: Option<usize>,
@@ -39,7 +39,7 @@ impl Create {
     pub fn run(&self) -> Result<()> {
         let mq = &mut posixmq::OpenOptions::readonly();
 
-        if let Some(m) = &self.permissions {
+        if let Some(m) = &self.mode {
             mq.mode(u32::from_str_radix(&m, 8)?);
         }
 

src/sysv.rs

@@ -0,0 +1,3 @@
+mod create;
+
+pub use create::Create;

src/sysv/create.rs

@@ -0,0 +1,31 @@
+use anyhow::Result;
+use clap::Clap;
+use log::info;
+use sysvmq::SysvMq;
+
+/// Create a SysV message queue
+#[derive(Clap, Debug)]
+pub struct Create {
+    /// Permissions (octal) to create the queue with (default: 0644)
+    #[clap(short, long)]
+    mode: Option<String>,
+    /// Key of the new queue
+    #[clap(value_name = "KEY")]
+    key: i32,
+}
+
+impl Create {
+    pub fn run(&self) -> Result<()> {
+        let mut mq = SysvMq::<String>::new();
+
+        if let Some(m) = &self.mode {
+            mq.mode(i32::from_str_radix(&m, 8)?);
+        }
+
+        mq.create(self.key)?;
+
+        info!("SysV message queue created, key: {}, id: {}", mq.key, mq.id);
+
+        Ok(())
+    }
+}