Add -q/--quiet/--has-match flag (#813)

Instead of printing to stdout, the program will return 1 as the exit
code if there are no matches and 0 otherwise.

CHANGELOG.md

@@ -3,6 +3,8 @@
 ## Features
 - Don't buffer command output from `--exec` when using a single thread. See #522
 
+- Add new `-q, --quiet` flag, see #303 (@Asha20)
+
 ## Bugfixes
 
 - Set default path separator to `/` in MSYS, see #537 and #730 (@aswild)

doc/fd.1

@@ -93,6 +93,13 @@ Limit the number of search results to 'count' and quit immediately.
 .B \-1
 Limit the search to a single result and quit immediately. This is an alias for '--max-results=1'.
 .TP
+.B \-q, \-\-quiet
+When the flag is present, the program does not print anything and will instead exit with a code of 0 if there is at least one search result.
+Otherwise, the exit code will be 1.
+This is mainly for usage in scripts and can be faster than checking for output because the search can be stopped early after the first match.
+.B \-\-has\-results
+can be used as an alias.
+.TP
 .B \-\-show-errors
 Enable the display of filesystem errors for situations such as insufficient
 permissions or dead symlinks.

src/app.rs

@@ -504,6 +504,20 @@ pub fn build_app() -> App<'static, 'static> {
                 .long_help("Limit the search to a single result and quit immediately. \
                                 This is an alias for '--max-results=1'.")
         )
+        .arg(
+            Arg::with_name("quiet")
+                .long("quiet")
+                .short("q")
+                .alias("has-results")
+                .hidden_short_help(true)
+                .conflicts_with_all(&["exec", "exec-batch", "list-details", "max-results"])
+                .long_help(
+                    "When the flag is present, the program does not print anything and will \
+                     return with an exit code of 0 if there is at least one match. Otherwise, the \
+                     exit code will be 1. \
+                     '--has-results' can be used as an alias."
+                )
+        )
         .arg(
             Arg::with_name("show-errors")
                 .long("show-errors")

src/exit_codes.rs

@@ -1,6 +1,7 @@
 #[derive(Debug, Clone, Copy, PartialEq)]
 pub enum ExitCode {
     Success,
+    HasResults(bool),
     GeneralError,
     KilledBySigint,
 }
@@ -9,6 +10,7 @@ impl From<ExitCode> for i32 {
     fn from(code: ExitCode) -> Self {
         match code {
             ExitCode::Success => 0,
+            ExitCode::HasResults(has_results) => !has_results as i32,
             ExitCode::GeneralError => 1,
             ExitCode::KilledBySigint => 130,
         }
@@ -17,7 +19,7 @@ impl From<ExitCode> for i32 {
 
 impl ExitCode {
     fn is_error(self) -> bool {
-        self != ExitCode::Success
+        i32::from(self) != 0
     }
 }
 

src/main.rs

@@ -346,6 +346,7 @@ fn run() -> Result<ExitCode> {
         follow_links: matches.is_present("follow"),
         one_file_system: matches.is_present("one-file-system"),
         null_separator: matches.is_present("null_separator"),
+        quiet: matches.is_present("quiet"),
         max_depth: matches
             .value_of("max-depth")
             .or_else(|| matches.value_of("rg-depth"))

src/options.rs

@@ -54,6 +54,10 @@ pub struct Options {
     /// The number of threads to use.
     pub threads: usize,
 
+    /// If true, the program doesn't print anything and will instead return an exit code of 0
+    /// if there's at least one match. Otherwise, the exit code will be 1.
+    pub quiet: bool,
+
     /// Time to buffer results internally before streaming to the console. This is useful to
     /// provide a sorted output, in case the total execution time is shorter than
     /// `max_buffer_time`.

src/walk.rs

@@ -233,6 +233,10 @@ fn spawn_receiver(
             for worker_result in rx {
                 match worker_result {
                     WorkerResult::Entry(value) => {
+                        if config.quiet {
+                            return ExitCode::HasResults(true);
+                        }
+
                         match mode {
                             ReceiverMode::Buffering => {
                                 buffer.push(value);
@@ -286,7 +290,11 @@ fn spawn_receiver(
                 }
             }
 
-            ExitCode::Success
+            if config.quiet {
+                ExitCode::HasResults(false)
+            } else {
+                ExitCode::Success
+            }
         }
     })
 }

tests/tests.rs

@@ -1425,6 +1425,19 @@ fn test_exec_with_separator() {
     );
 }
 
+/// Non-zero exit code (--quiet)
+#[test]
+fn test_quiet() {
+    let dirs = &[];
+    let files = &["a.foo", "b.foo"];
+    let te = TestEnv::new(dirs, files);
+
+    te.assert_output(&["-q"], "");
+    te.assert_output(&["--quiet"], "");
+    te.assert_output(&["--has-results"], "");
+    te.assert_failure_with_error(&["--quiet", "c.foo"], "")
+}
+
 /// Literal search (--fixed-strings)
 #[test]
 fn test_fixed_strings() {