Infer path, add -e option to monitor files based on file extensions

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "watchexec"
-version = "0.8.0"
+version = "0.9.0"
 authors = ["Matt Green <mattgreenrocks@gmail.com>"]
 
 [profile.release]

README.md

@@ -11,15 +11,16 @@ Example use cases:
 
 ##Status
 
-Beta: CLI arguments subject to change
+Beta: CLI arguments stabilizing
 
 ##Features
 
 * Simple invocation and use
 * Runs on OS X, Linux and Windows
 * Monitors path specified on command line for changes
-	* Uses most efficient event polling mechanism, based on platform (except for [BSD](https://github.com/passcod/rsnotify#todo))
+	* Uses most efficient event polling mechanism for your platform (except for [BSD](https://github.com/passcod/rsnotify#todo))
 * Coalesces multiple filesystem events into one, for editors that use swap/backup files during saving
+* Support for watching files with a specific extension
 * Support for filtering/ignoring events based on glob patterns
 * Optionally clears screen between executions
 * Does not require a language runtime
@@ -30,21 +31,19 @@ Beta: CLI arguments subject to change
 * Not tied to any particular language or ecosystem
 * Does not require a cryptic command line involving `xargs`
 
-##Usage
+##Usage Examples
 
-Call `make test` when there are any changes in the `src` directory:
+Watch all JavaScript, CSS and HTML files in the current directory and all subdirectories for changes, running `make` when a change is detected:
 
-    $ watchexec src make test
+	$ watchexec --exts js,css,html make
 
-Call `make test` when any Python file changes in this directory, or a subdirectory:
+Watch all files below `src` and subdirectories for changes, running `make test` when a change is detected:
 
-    $ watchexec -f '*.py' . make test
+    $ watchexec --watch src make test
 
 Call `make test` when any file changes in this directory/subdirectory, except for everything below `target`:
 
-    $ watchexec -i target . make test
-
-Always quote glob patterns (*.py)!
+    $ watchexec -i target make
 
 ##Installation
 

src/filter.rs

@@ -19,6 +19,24 @@ impl Filter {
         }
     }
 
+    pub fn add_extension(&mut self, extension: &str) -> Result<(), PatternError> {
+        let mut pattern = String::new();
+
+        for ext in extension.split(",") {
+            pattern.clear();
+            pattern.push_str("*");
+
+            if !ext.starts_with(".") {
+                pattern.push_str(".");
+            }
+            pattern.push_str(ext);
+
+            try!(self.add_filter(&pattern));
+        }
+
+        Ok(())
+    }
+
     pub fn add_filter(&mut self, pattern: &str) -> Result<Pattern, PatternError> {
         let compiled = try!(self.pattern_for(pattern));
         self.filters.push(compiled.clone());

src/main.rs

@@ -66,15 +66,23 @@ fn wait(rx: &Receiver<Event>, filter: &Filter, debug: bool) -> Result<Event, Rec
 
 fn main() {
     let args = App::new("watchexec")
-        .version("0.8")
+        .version("0.9")
         .about("Runs a command when any of the specified files/directories are modified")
         .arg(Arg::with_name("path")
-            .help("Path to watch for changes")
-            .required(true))
+            .help("Path(s) to watch for changes")
+            .short("w")
+            .long("watch")
+            .takes_value(true)
+            .default_value("."))
         .arg(Arg::with_name("command")
             .help("Command to run")
             .multiple(true)
             .required(true))
+        .arg(Arg::with_name("extensions")
+             .help("Comma-separated list of file extensions to watch (js,css,html)")
+             .short("e")
+             .long("exts")
+             .takes_value(true))
         .arg(Arg::with_name("clear")
             .help("Clear screen before running command")
             .short("c")
@@ -89,14 +97,16 @@ fn main() {
              .long("filter")
              .number_of_values(1)
              .multiple(true)
-             .takes_value(true))
+             .takes_value(true)
+             .value_name("pattern"))
         .arg(Arg::with_name("ignore")
              .help("Ignore events from paths matching a pattern")
              .short("i")
              .long("ignore")
              .number_of_values(1)
              .multiple(true)
-             .takes_value(true))
+             .takes_value(true)
+             .value_name("pattern"))
         .get_matches();
 
     let debug = args.is_present("debug");
@@ -110,6 +120,12 @@ fn main() {
         filter.add_ignore(p).expect("bad default filter");
     }
 
+    if let Some(extensions) = args.values_of("extensions") {
+        for ext in extensions {
+            filter.add_extension(ext).expect("bad extension");
+        }
+    }
+
     if let Some(filters) = args.values_of("filter") {
         for p in filters {
             filter.add_filter(p).expect("bad filter");