Add --no-messages flag.

This flag is similar to what's found in grep: it will suppress all error
messages, such as those shown when a particular file couldn't be read.

Closes #149

3 files changed, 40 insertions, 11 deletions

diff --git a/src/args.rs b/src/args.rs
index 66bb5cd9..4a3b1115 100644
--- a/src/args.rs
+++ b/src/args.rs
@@ -153,6 +153,9 @@ Less common options:
         when ripgrep thinks it will be faster. (Note that mmap searching
         doesn't currently support the various context related options.)
 
+    --no-messages
+        Suppress all error messages.
+
     --no-mmap
         Never use memory maps, even when they might be faster.
 
@@ -256,6 +259,7 @@ pub struct RawArgs {
     flag_no_ignore_parent: bool,
     flag_no_ignore_vcs: bool,
     flag_no_line_number: bool,
+    flag_no_messages: bool,
     flag_no_mmap: bool,
     flag_no_filename: bool,
     flag_null: bool,
@@ -306,6 +310,7 @@ pub struct Args {
     no_ignore: bool,
     no_ignore_parent: bool,
     no_ignore_vcs: bool,
+    no_messages: bool,
     null: bool,
     quiet: bool,
     replace: Option<Vec<u8>>,
@@ -429,6 +434,7 @@ impl RawArgs {
             no_ignore_vcs:
                 // --no-ignore implies --no-ignore-vcs
                 self.flag_no_ignore_vcs || no_ignore,
+            no_messages: self.flag_no_messages,
             null: self.flag_null,
             quiet: self.flag_quiet,
             replace: self.flag_replace.clone().map(|s| s.into_bytes()),
@@ -711,6 +717,11 @@ impl Args {
         self.type_list
     }
 
+    /// Returns true if error messages should be suppressed.
+    pub fn no_messages(&self) -> bool {
+        self.no_messages
+    }
+
     /// Create a new recursive directory iterator over the paths in argv.
     pub fn walker(&self) -> ignore::Walk {
         self.walker_builder().build()
@@ -730,7 +741,9 @@ impl Args {
         }
         for path in &self.ignore_files {
             if let Some(err) = wd.add_ignore(path) {
-                eprintln!("{}", err);
+                if !self.no_messages {
+                    eprintln!("{}", err);
+                }
             }
         }
 
diff --git a/src/main.rs b/src/main.rs
index 33f99ad9..41f13be8 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -124,7 +124,7 @@ fn run_parallel(args: Arc<Args>) -> Result<u64> {
             if quiet_matched.has_match() {
                 return Quit;
             }
-            let dent = match get_or_log_dir_entry(result) {
+            let dent = match get_or_log_dir_entry(result, args.no_messages()) {
                 None => return Continue,
                 Some(dent) => dent,
             };
@@ -160,7 +160,9 @@ fn run_parallel(args: Arc<Args>) -> Result<u64> {
         })
     });
     if !args.paths().is_empty() && paths_searched.load(Ordering::SeqCst) == 0 {
-        eprint_nothing_searched();
+        if !args.no_messages() {
+            eprint_nothing_searched();
+        }
     }
     Ok(match_count.load(Ordering::SeqCst) as u64)
 }
@@ -171,7 +173,7 @@ fn run_one_thread(args: Arc<Args>) -> Result<u64> {
     let mut paths_searched: u64 = 0;
     let mut match_count = 0;
     for result in args.walker() {
-        let dent = match get_or_log_dir_entry(result) {
+        let dent = match get_or_log_dir_entry(result, args.no_messages()) {
             None => continue,
             Some(dent) => dent,
         };
@@ -193,7 +195,9 @@ fn run_one_thread(args: Arc<Args>) -> Result<u64> {
             };
     }
     if !args.paths().is_empty() && paths_searched == 0 {
-        eprint_nothing_searched();
+        if !args.no_messages() {
+            eprint_nothing_searched();
+        }
     }
     Ok(match_count)
 }
@@ -211,10 +215,11 @@ fn run_files_parallel(args: Arc<Args>) -> Result<u64> {
         }
         file_count
     });
+    let no_messages = args.no_messages();
     args.walker_parallel().run(move || {
         let tx = tx.clone();
         Box::new(move |result| {
-            if let Some(dent) = get_or_log_dir_entry(result) {
+            if let Some(dent) = get_or_log_dir_entry(result, no_messages) {
                 tx.send(dent).unwrap();
             }
             ignore::WalkState::Continue
@@ -228,7 +233,7 @@ fn run_files_one_thread(args: Arc<Args>) -> Result<u64> {
     let mut printer = args.printer(term);
     let mut file_count = 0;
     for result in args.walker() {
-        let dent = match get_or_log_dir_entry(result) {
+        let dent = match get_or_log_dir_entry(result, args.no_messages()) {
             None => continue,
             Some(dent) => dent,
         };
@@ -251,15 +256,20 @@ fn run_types(args: Arc<Args>) -> Result<u64> {
 
 fn get_or_log_dir_entry(
     result: result::Result<ignore::DirEntry, ignore::Error>,
+    no_messages: bool,
 ) -> Option<ignore::DirEntry> {
     match result {
         Err(err) => {
-            eprintln!("{}", err);
+            if !no_messages {
+                eprintln!("{}", err);
+            }
             None
         }
         Ok(dent) => {
             if let Some(err) = dent.error() {
-                eprintln!("{}", err);
+                if !no_messages {
+                    eprintln!("{}", err);
+                }
             }
             if !dent.file_type().map_or(true, |x| x.is_file()) {
                 None
diff --git a/src/worker.rs b/src/worker.rs
index bc8a62b3..0ade140a 100644
--- a/src/worker.rs
+++ b/src/worker.rs
@@ -35,6 +35,7 @@ struct Options {
     invert_match: bool,
     line_number: bool,
     max_count: Option<u64>,
+    no_messages: bool,
     quiet: bool,
     text: bool,
 }
@@ -51,6 +52,7 @@ impl Default for Options {
             invert_match: false,
             line_number: false,
             max_count: None,
+            no_messages: false,
             quiet: false,
             text: false,
         }
@@ -186,7 +188,9 @@ impl Worker {
                 let file = match File::open(path) {
                     Ok(file) => file,
                     Err(err) => {
-                        eprintln!("{}: {}", path.display(), err);
+                        if !self.opts.no_messages {
+                            eprintln!("{}: {}", path.display(), err);
+                        }
                         return 0;
                     }
                 };
@@ -205,7 +209,9 @@ impl Worker {
                 count
             }
             Err(err) => {
-                eprintln!("{}", err);
+                if !self.opts.no_messages {
+                    eprintln!("{}", err);
+                }
                 0
             }
         }