Initial Commit.

.gitignore

@@ -0,0 +1,3 @@
+target
+Cargo.lock
+target

Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "runwhen"
+version = "0.1.0"
+authors = ["Jeremy Wall <jeremy@marzhillstudios.com>"]
+description = "Runs a command on user specified triggers."
+
+[dependencies]
+clap = "~2.19.0"
+humantime = "~1.0.0"
+notify = "~3.0.0"
+md5 = "~0.3.2"
+subprocess = "~0.1.7"

LICENSE.txt

@@ -0,0 +1,202 @@
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README.md

@@ -0,0 +1,30 @@
+# runwhen - A utility that executes commands on user defined triggers.
+
+## Usage
+
+```
+Runs a command on user defined triggers.
+
+USAGE:
+    runwhen --cmd <cmd> [SUBCOMMAND]
+
+FLAGS:
+    -h, --help       Prints help information
+    -V, --version    Prints version information
+
+OPTIONS:
+    -c, --cmd <cmd>    Command to run on supplied triggers
+
+SUBCOMMANDS:
+    help       Prints this message or the help of the given subcommand(s)
+    success    Trigger that fires if a command runs successful.
+    timer      Trigger that fires on a timer.
+    watch      Trigger that fires when a file or directory changes.
+```
+
+## Description
+
+I wanted a project to learn Rust on and this one scratches an itch I've had for
+a while. runwhen executes a command on a user specified trigger. There are other
+utilities out there that will execute on a timer or when a file changes but I
+haven't seen any that bundled all the types of triggers into one utility.

src/error.rs

@@ -0,0 +1,42 @@
+// Copyright 2017 Jeremy Wall <jeremy@marzhillstudios.com>
+//
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+use std::error::Error;
+use std::fmt;
+
+use notify;
+
+#[derive(Debug)]
+pub struct CommandError {
+    msg: String,
+}
+
+impl CommandError {
+    pub fn new(msg: String) -> CommandError {
+        CommandError{
+            msg: msg
+        }
+    }
+}
+
+impl fmt::Display for CommandError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{:?}", self.msg)
+    }
+}
+
+impl From<notify::Error> for CommandError {
+    fn from(e: notify::Error) -> CommandError {
+        CommandError::new(e.description().to_string())
+    }
+}

src/events.rs

@@ -0,0 +1,39 @@
+// Copyright 2017 Jeremy Wall <jeremy@marzhillstudios.com>
+//
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+use notify::DebouncedEvent;
+
+#[derive(PartialEq,Clone)]
+pub enum WatchEventType {
+    Touched,
+    Changed,
+    Error,
+    Ignore
+}
+
+impl From<DebouncedEvent> for WatchEventType {
+    fn from(e: DebouncedEvent) -> WatchEventType {
+        println!("Found event: {:?}", e);
+        match e {
+            DebouncedEvent::Chmod(_) => WatchEventType::Touched,
+            DebouncedEvent::Create(_) => WatchEventType::Touched,
+            DebouncedEvent::Remove(_) => WatchEventType::Changed,
+            DebouncedEvent::Rename(_, _) => WatchEventType::Changed,
+            DebouncedEvent::Write(_) => WatchEventType::Changed,
+            DebouncedEvent::NoticeRemove(_) => WatchEventType::Ignore,
+            DebouncedEvent::NoticeWrite(_) => WatchEventType::Ignore,
+            DebouncedEvent::Rescan => WatchEventType::Ignore,
+            DebouncedEvent::Error(_, _) => WatchEventType::Ignore
+        }
+    }
+}

src/exec.rs

@@ -0,0 +1,57 @@
+// Copyright 2017 Jeremy Wall <jeremy@marzhillstudios.com>
+//
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+use std::thread;
+use std::time::Duration;
+
+use subprocess::{Exec,PopenError,ExitStatus};
+
+use traits::Process;
+use error::CommandError;
+
+pub fn run_cmd(cmd: &str) -> Result<(), PopenError> {
+    Exec::shell(cmd).join()?;
+    Ok(())
+}
+
+fn is_cmd_success(cmd: &str) -> bool {
+    match Exec::shell(cmd).join() {
+        Ok(ExitStatus::Exited(code)) => code == 0,
+        _ => false,
+    }
+}
+
+pub struct ExecProcess<'a> {
+    test_cmd: &'a str,
+    cmd: &'a str,
+    poll: Duration,
+}
+
+impl<'a> ExecProcess<'a> {
+    pub fn new(test_cmd: &'a str, cmd: &'a str, poll: Duration) -> ExecProcess<'a> {
+        ExecProcess{test_cmd: test_cmd, cmd: cmd, poll: poll}
+    }
+}
+
+impl<'a> Process for ExecProcess<'a> {
+    fn run(&self) -> Result<(), CommandError> {
+        loop {
+            if is_cmd_success(self.test_cmd) {
+                if let Err(err) = run_cmd(self.cmd) {
+                    println!("{:?}", err)
+                }
+            }
+            thread::sleep(self.poll);
+        }
+    }
+}

src/file.rs

@@ -0,0 +1,116 @@
+// Copyright 2017 Jeremy Wall <jeremy@marzhillstudios.com>
+//
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+use std::thread;
+use std::sync::{Arc,RwLock};
+use std::time::Duration;
+use std::path::Path;
+use std::sync::mpsc::channel;
+
+use notify::{Watcher,RecursiveMode,watcher};
+
+use traits::Process;
+use error::CommandError;
+use events::WatchEventType;
+use exec::run_cmd;
+
+pub struct FileProcess<'a> {
+    cmd: &'a str,
+    file: &'a str,
+    method: WatchEventType,
+    poll: Duration,
+}
+
+impl<'a> FileProcess<'a> {
+    pub fn new(cmd: &'a str, file: &'a str, method: WatchEventType, poll: Duration) -> FileProcess<'a> {
+        FileProcess{ cmd: cmd, file: file, method: method, poll: poll}
+    }
+}
+
+fn spawn_runner_thread(lock: Arc<RwLock<bool>>, cmd: String, poll: Duration) {
+    thread::spawn(move || {
+        loop {
+            // Wait our requisit number of seconds
+            thread::sleep(poll);
+            // Default to not running the command.
+            let should_run = { // get a new scope for our read lock.
+                // Check our evt drop off.
+                *(lock.read().unwrap())
+            }; // drop our read lock
+            if should_run {
+                { // Set a new scope for our write lock.
+                    let mut signal = lock.write().unwrap();
+                    // set signal to false so we won't trigger on the
+                    // next loop iteration unless we recieved more events.
+                    *signal = false;
+                    // Run our command!
+                    if let Err(err) = run_cmd(&cmd) {
+                        println!("{:?}", err)
+                    }
+                } // drop our write lock.
+            }
+        }
+    });
+}
+
+fn wait_for_fs_events(lock: Arc<RwLock<bool>>, method: WatchEventType, file: &str) -> Result<(), CommandError> {
+    // Notify requires a channel for communication.
+    let (tx, rx) = channel();
+    let mut watcher = try!(watcher(tx, Duration::from_secs(1)));
+    // TODO(jwall): Better error handling.
+    try!(watcher.watch(file, RecursiveMode::Recursive));
+    println!("Watching {:?}", file);
+    loop {
+        let evt: WatchEventType = match rx.recv() {
+            Ok(event) => {
+                WatchEventType::from(event)
+            },
+            Err(_) => {
+                WatchEventType::Error
+            }
+        };
+        match evt {
+            WatchEventType::Ignore => {
+                // We ignore this one.
+            },
+            WatchEventType::Error => {
+                // We log this one.
+            },
+            WatchEventType::Touched => {
+                if method == WatchEventType::Touched {
+                    let mut signal = lock.write().unwrap();
+                    *signal = true;
+                }
+            },
+            WatchEventType::Changed => {
+                let mut signal = lock.write().unwrap();
+                *signal = true;
+            }
+        }
+    }
+}
+
+impl<'a> Process for FileProcess<'a> {
+    fn run(&self) -> Result<(), CommandError> {
+    // NOTE(jwall): this is necessary because notify::fsEventWatcher panics
+    // if the path doesn't exist. :-(
+    if !Path::new(self.file).exists() {
+        return Err(CommandError::new(format!("No such path! {0}", self.file).to_string()))
+    }
+    // TODO(jeremy): Is this sufficent or do we want to ignore
+    // any events that come in while the command is running?
+    let lock = Arc::new(RwLock::new(false));
+    spawn_runner_thread(lock.clone(), self.cmd.to_string(), self.poll);
+    wait_for_fs_events(lock, self.method.clone(), self.file)
+    }
+}

src/main.rs

@@ -0,0 +1,129 @@
+// Copyright 2017 Jeremy Wall <jeremy@marzhillstudios.com>
+//
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+#[macro_use]
+extern crate clap;
+extern crate humantime;
+extern crate md5;
+extern crate notify;
+extern crate subprocess;
+
+use std::process;
+use std::str::FromStr;
+
+mod traits;
+mod file;
+mod timer;
+mod error;
+mod events;
+mod exec;
+
+use traits::Process;
+use file::FileProcess;
+use timer::TimerProcess;
+use exec::ExecProcess;
+use events::WatchEventType;
+
+fn do_flags<'a>() -> clap::ArgMatches<'a> {
+    clap_app!(
+        runwhen =>
+            (version: crate_version!())
+            (author: crate_authors!())
+            (about: "Runs a command on user defined triggers.")
+            (@arg cmd: -c --cmd +required +takes_value "Command to run on supplied triggers")
+            (@subcommand watch =>
+             (about: "Trigger that fires when a file or directory changes.")
+             // TODO(jeremy): We need to support filters
+             (@arg file: -f --file +takes_value "File/Directory to watch. (default current working directory)")
+             (@arg filetouch: --touch "Watches for attribute modifications as well as content changes.")
+             (@arg wait: --poll +takes_value "How frequently to poll for events (default 5s)")
+            )
+            (@subcommand timer =>
+             (about: "Trigger that fires on a timer.")
+             (@arg duration: -t --duration +required +takes_value "Defines timer frequency.")
+             (@arg repeat: -n --repeat +takes_value "Defines an optional max number times to run on repeat.")
+            )
+            (@subcommand success =>
+             (about: "Trigger that fires if a command runs successful.")
+             (@arg ifcmd: --if +required +takes_value "The command to test for successful exit from")
+             (@arg wait: --poll +takes_value "How frequently to test command (default 5s)")
+            )
+    ).get_matches()
+}
+
+fn main() {
+    let app = do_flags();
+    // Unwrap because this flag is required.
+    let cmd = app.value_of("cmd").unwrap();
+    let mut process: Option<Box<Process>> = None;
+    if let Some(matches) = app.subcommand_matches("watch") {
+        // Unwrap because this flag is required.
+        let file = matches.value_of("file").unwrap_or(".");
+        let mut method = WatchEventType::Changed;
+        if matches.is_present("filetouch") {
+            method = WatchEventType::Touched;
+        }
+        let poll = matches.value_of("poll").unwrap_or("5s");
+        let dur = humantime::parse_duration(poll).unwrap();
+        process = Some(Box::new(FileProcess::new(cmd, file, method, dur)));
+    } else if let Some(matches) = app.subcommand_matches("timer") {
+        // Unwrap because this flag is required.
+        let dur = humantime::parse_duration(matches.value_of("duration").unwrap());
+        match dur {
+            Ok(duration) =>{
+                let max_repeat = if let Some(val) = matches.value_of("repeat") {
+                    match u32::from_str(val) {
+                        Ok(n) => Some(n),
+                        Err(e) => {
+                            println!("Invalid --repeat value {}", e);
+                            println!("{}", matches.usage());
+                            process::exit(1)
+                        }
+                    }
+                } else {
+                    None
+                };
+                process = Some(Box::new(TimerProcess::new(cmd, duration, max_repeat)));
+            },
+            Err(msg) => {
+                println!("Malformed duration {:?}", msg);
+                process::exit(1);
+            }
+        }
+    } else if let Some(matches) = app.subcommand_matches("success") {
+        // unwrap because this is required.
+        let ifcmd = matches.value_of("ifcmd").unwrap();
+        let dur = humantime::parse_duration(
+            matches.value_of("poll").unwrap_or("5s"));
+        process = match dur {
+            Ok(duration) => Some(Box::new(ExecProcess::new(ifcmd, cmd, duration))),
+            Err(msg) => {
+                println!("Malformed poll {:?}", msg);
+                process::exit(1)
+            }
+        }
+    }
+    match process {
+        Some(process) => match process.run() {
+            Ok(_) => return,
+            Err(err) => {
+                println!("{0}", err);
+                process::exit(1)
+            }
+        },
+        None => {
+            println!("You must specify a subcommand.");
+            process::exit(1)
+        },
+    }
+}

src/timer.rs

@@ -0,0 +1,47 @@
+// Copyright 2017 Jeremy Wall <jeremy@marzhillstudios.com>
+//
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+use std::thread;
+use std::time::Duration;
+
+use traits::Process;
+use error::CommandError;
+use exec::run_cmd;
+
+pub struct TimerProcess<'a> {
+    cmd: &'a str,
+    poll_duration: Duration,
+    max_repeat: Option<u32>
+}
+
+impl<'a> TimerProcess<'a> {
+    pub fn new(cmd: &'a str, poll_duration: Duration, max_repeat: Option<u32>) -> TimerProcess<'a> {
+        TimerProcess{cmd: cmd, poll_duration: poll_duration, max_repeat: max_repeat}
+    }
+}
+
+impl<'a> Process for TimerProcess<'a> {
+    fn run(&self) -> Result<(), CommandError> {
+        let mut counter = 0;
+        loop {
+            if self.max_repeat.is_some() && counter >= self.max_repeat.unwrap() {
+                return Ok(());
+            }
+            if let Err(err) = run_cmd(self.cmd) {
+                println!("{:?}", err)
+            }
+            thread::sleep(self.poll_duration);
+            if self.max_repeat.is_some() { counter += 1 }
+        }
+    }
+}

src/traits.rs

@@ -0,0 +1,18 @@
+// Copyright 2017 Jeremy Wall <jeremy@marzhillstudios.com>
+//
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+use error::CommandError;
+
+pub trait Process {
+    fn run(&self) -> Result<(), CommandError>;
+}