Add support for batch execution of command

src/app.rs

@@ -121,6 +121,16 @@ pub fn build_app() -> App<'static, 'static> {
                 .value_terminator(";")
                 .value_name("cmd"),
         )
+        .arg(
+            arg("exec-batch")
+                .long("exec-batch")
+                .short("X")
+                .min_values(1)
+                .allow_hyphen_values(true)
+                .value_terminator(";")
+                .value_name("cmd")
+                .conflicts_with("exec"),
+        )
         .arg(
             arg("exclude")
                 .long("exclude")
@@ -277,6 +287,18 @@ fn usage() -> HashMap<&'static str, Help> {
              '{//}': parent directory\n  \
              '{.}':  path without file extension\n  \
              '{/.}': basename without file extension");
+    doc!(h, "exec-batch"
+        , "Execute a command with all search results at once"
+        , "Execute a command with all search results at once.\n\
+           All arguments following --exec-batch are taken to be arguments to the command until the \
+           argument ';' is encountered.\n\
+           A single occurence of the following placeholders is authorized and substituted by the paths derived from the \
+           search results before the command is executed:\n  \
+             '{}':   path\n  \
+             '{/}':  basename\n  \
+             '{//}': parent directory\n  \
+             '{.}':  path without file extension\n  \
+             '{/.}': basename without file extension");
     doc!(h, "exclude"
         , "Exclude entries that match the given glob pattern"
         , "Exclude files/directories that match the given glob pattern. This overrides any \

src/exec/command.rs

@@ -9,10 +9,10 @@
 use std::io;
 use std::io::Write;
 use std::process::Command;
-use std::sync::{Arc, Mutex};
+use std::sync::Mutex;
 
 /// Executes a command.
-pub fn execute_command(mut cmd: Command, out_perm: Arc<Mutex<()>>) {
+pub fn execute_command(mut cmd: Command, out_perm: &Mutex<()>) {
     // Spawn the supplied command.
     let output = cmd.output();
 

src/exec/job.rs

@@ -44,3 +44,16 @@ pub fn job(
         cmd.generate_and_execute(&value, Arc::clone(&out_perm));
     }
 }
+
+pub fn batch(rx: Receiver<WorkerResult>, cmd: &CommandTemplate, show_filesystem_errors: bool) {
+    let paths = rx.iter().filter_map(|value| match value {
+        WorkerResult::Entry(val) => Some(val),
+        WorkerResult::Error(err) => {
+            if show_filesystem_errors {
+                print_error!("{}", err);
+            }
+            None
+        }
+    });
+    cmd.generate_and_execute_batch(paths);
+}

src/exec/mod.rs

@@ -13,28 +13,61 @@ mod job;
 mod token;
 
 use std::borrow::Cow;
-use std::path::Path;
-use std::process::Command;
+use std::path::{Path, PathBuf};
+use std::process::{Command, Stdio};
 use std::sync::{Arc, Mutex};
 
 use regex::Regex;
 
 use self::command::execute_command;
 use self::input::{basename, dirname, remove_extension};
-pub use self::job::job;
+pub use self::job::{batch, job};
 use self::token::Token;
 
+/// Execution mode of the command
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub enum ExecutionMode {
+    /// Command is executed for each search result
+    OneByOne,
+    /// Command is run for a batch of results at once
+    Batch,
+}
+
 /// Represents a template that is utilized to generate command strings.
 ///
 /// The template is meant to be coupled with an input in order to generate a command. The
 /// `generate_and_execute()` method will be used to generate a command and execute it.
 #[derive(Debug, Clone, PartialEq)]
 pub struct CommandTemplate {
     args: Vec<ArgumentTemplate>,
+    mode: ExecutionMode,
 }
 
 impl CommandTemplate {
     pub fn new<I, S>(input: I) -> CommandTemplate
+    where
+        I: IntoIterator<Item = S>,
+        S: AsRef<str>,
+    {
+        Self::build(input, ExecutionMode::OneByOne)
+    }
+
+    pub fn new_batch<I, S>(input: I) -> Result<CommandTemplate, &'static str>
+    where
+        I: IntoIterator<Item = S>,
+        S: AsRef<str>,
+    {
+        let cmd = Self::build(input, ExecutionMode::Batch);
+        if cmd.number_of_tokens() > 1 {
+            return Err("Only one placeholder allowed for batch commands");
+        }
+        if cmd.args[0].has_tokens() {
+            return Err("First argument of exec-batch is expected to be a fixed executable");
+        }
+        Ok(cmd)
+    }
+
+    fn build<I, S>(input: I, mode: ExecutionMode) -> CommandTemplate
     where
         I: IntoIterator<Item = S>,
         S: AsRef<str>,
@@ -91,26 +124,68 @@ impl CommandTemplate {
             args.push(ArgumentTemplate::Tokens(vec![Token::Placeholder]));
         }
 
-        CommandTemplate { args }
+        CommandTemplate { args, mode }
+    }
+
+    fn number_of_tokens(&self) -> usize {
+        self.args.iter().filter(|arg| arg.has_tokens()).count()
+    }
+
+    fn prepare_path(input: &Path) -> String {
+        input
+            .strip_prefix(".")
+            .unwrap_or(input)
+            .to_string_lossy()
+            .into_owned()
     }
 
     /// Generates and executes a command.
     ///
     /// Using the internal `args` field, and a supplied `input` variable, a `Command` will be
     /// build. Once all arguments have been processed, the command is executed.
     pub fn generate_and_execute(&self, input: &Path, out_perm: Arc<Mutex<()>>) {
-        let input = input
-            .strip_prefix(".")
-            .unwrap_or(input)
-            .to_string_lossy()
-            .into_owned();
+        let input = Self::prepare_path(input);
 
         let mut cmd = Command::new(self.args[0].generate(&input).as_ref());
         for arg in &self.args[1..] {
             cmd.arg(arg.generate(&input).as_ref());
         }
 
-        execute_command(cmd, out_perm)
+        execute_command(cmd, &out_perm)
+    }
+
+    pub fn in_batch_mode(&self) -> bool {
+        self.mode == ExecutionMode::Batch
+    }
+
+    pub fn generate_and_execute_batch<I>(&self, paths: I)
+    where
+        I: Iterator<Item = PathBuf>,
+    {
+        let mut cmd = Command::new(self.args[0].generate("").as_ref());
+        cmd.stdin(Stdio::inherit());
+        cmd.stdout(Stdio::inherit());
+        cmd.stderr(Stdio::inherit());
+
+        let mut paths = paths.map(|p| Self::prepare_path(&p));
+        let mut has_path = false;
+
+        for arg in &self.args[1..] {
+            if arg.has_tokens() {
+                // A single `Tokens` is expected
+                // So we can directy consume the iterator once and for all
+                for path in &mut paths {
+                    cmd.arg(arg.generate(&path).as_ref());
+                    has_path = true;
+                }
+            } else {
+                cmd.arg(arg.generate("").as_ref());
+            }
+        }
+
+        if has_path {
+            execute_command(cmd, &Mutex::new(()));
+        }
     }
 }
 
@@ -125,6 +200,13 @@ enum ArgumentTemplate {
 }
 
 impl ArgumentTemplate {
+    pub fn has_tokens(&self) -> bool {
+        match self {
+            ArgumentTemplate::Tokens(_) => true,
+            _ => false,
+        }
+    }
+
     pub fn generate<'a>(&'a self, path: &str) -> Cow<'a, str> {
         use self::Token::*;
 
@@ -162,6 +244,7 @@ mod tests {
                     ArgumentTemplate::Text("${SHELL}:".into()),
                     ArgumentTemplate::Tokens(vec![Token::Placeholder]),
                 ],
+                mode: ExecutionMode::OneByOne,
             }
         );
     }
@@ -175,6 +258,7 @@ mod tests {
                     ArgumentTemplate::Text("echo".into()),
                     ArgumentTemplate::Tokens(vec![Token::NoExt]),
                 ],
+                mode: ExecutionMode::OneByOne,
             }
         );
     }
@@ -188,6 +272,7 @@ mod tests {
                     ArgumentTemplate::Text("echo".into()),
                     ArgumentTemplate::Tokens(vec![Token::Basename]),
                 ],
+                mode: ExecutionMode::OneByOne,
             }
         );
     }
@@ -201,6 +286,7 @@ mod tests {
                     ArgumentTemplate::Text("echo".into()),
                     ArgumentTemplate::Tokens(vec![Token::Parent]),
                 ],
+                mode: ExecutionMode::OneByOne,
             }
         );
     }
@@ -214,6 +300,7 @@ mod tests {
                     ArgumentTemplate::Text("echo".into()),
                     ArgumentTemplate::Tokens(vec![Token::BasenameNoExt]),
                 ],
+                mode: ExecutionMode::OneByOne,
             }
         );
     }
@@ -231,7 +318,27 @@ mod tests {
                         Token::Text(".ext".into())
                     ]),
                 ],
+                mode: ExecutionMode::OneByOne,
             }
         );
     }
+
+    #[test]
+    fn tokens_single_batch() {
+        assert_eq!(
+            CommandTemplate::new_batch(&["echo", "{.}"]).unwrap(),
+            CommandTemplate {
+                args: vec![
+                    ArgumentTemplate::Text("echo".into()),
+                    ArgumentTemplate::Tokens(vec![Token::NoExt]),
+                ],
+                mode: ExecutionMode::Batch,
+            }
+        );
+    }
+
+    #[test]
+    fn tokens_multiple_batch() {
+        assert!(CommandTemplate::new_batch(&["echo", "{.}", "{}"]).is_err());
+    }
 }

src/main.rs

@@ -142,7 +142,16 @@ fn main() {
         None
     };
 
-    let command = matches.values_of("exec").map(CommandTemplate::new);
+    let command = matches
+        .values_of("exec")
+        .map(CommandTemplate::new)
+        .or_else(|| {
+            matches.values_of("exec-batch").map(|m| {
+                CommandTemplate::new_batch(m).unwrap_or_else(|e| {
+                    print_error_and_exit!("{}", e);
+                })
+            })
+        });
 
     let size_limits: Vec<SizeFilter> = matches
         .values_of("size")

src/walk.rs

@@ -126,34 +126,38 @@ pub fn scan(path_vec: &[PathBuf], pattern: Arc<Regex>, config: Arc<FdOptions>) {
     let receiver_thread = thread::spawn(move || {
         // This will be set to `Some` if the `--exec` argument was supplied.
         if let Some(ref cmd) = rx_config.command {
-            let shared_rx = Arc::new(Mutex::new(rx));
+            if cmd.in_batch_mode() {
+                exec::batch(rx, cmd, show_filesystem_errors);
+            } else {
+                let shared_rx = Arc::new(Mutex::new(rx));
 
-            let out_perm = Arc::new(Mutex::new(()));
+                let out_perm = Arc::new(Mutex::new(()));
 
-            // TODO: the following line is a workaround to replace the `unsafe` block that was
-            // previously used here to avoid the (unnecessary?) cloning of the command. The
-            // `unsafe` block caused problems on some platforms (SIGILL instructions on Linux) and
-            // therefore had to be removed.
-            let cmd = Arc::new(cmd.clone());
+                // TODO: the following line is a workaround to replace the `unsafe` block that was
+                // previously used here to avoid the (unnecessary?) cloning of the command. The
+                // `unsafe` block caused problems on some platforms (SIGILL instructions on Linux) and
+                // therefore had to be removed.
+                let cmd = Arc::new(cmd.clone());
 
-            // Each spawned job will store it's thread handle in here.
-            let mut handles = Vec::with_capacity(threads);
-            for _ in 0..threads {
-                let rx = Arc::clone(&shared_rx);
-                let cmd = Arc::clone(&cmd);
-                let out_perm = Arc::clone(&out_perm);
+                // Each spawned job will store it's thread handle in here.
+                let mut handles = Vec::with_capacity(threads);
+                for _ in 0..threads {
+                    let rx = Arc::clone(&shared_rx);
+                    let cmd = Arc::clone(&cmd);
+                    let out_perm = Arc::clone(&out_perm);
 
-                // Spawn a job thread that will listen for and execute inputs.
-                let handle =
-                    thread::spawn(move || exec::job(rx, cmd, out_perm, show_filesystem_errors));
+                    // Spawn a job thread that will listen for and execute inputs.
+                    let handle =
+                        thread::spawn(move || exec::job(rx, cmd, out_perm, show_filesystem_errors));
 
-                // Push the handle of the spawned thread into the vector for later joining.
-                handles.push(handle);
-            }
+                    // Push the handle of the spawned thread into the vector for later joining.
+                    handles.push(handle);
+                }
 
-            // Wait for all threads to exit before exiting the program.
-            for h in handles {
-                h.join().unwrap();
+                // Wait for all threads to exit before exiting the program.
+                for h in handles {
+                    h.join().unwrap();
+                }
             }
         } else {
             let start = time::Instant::now();