1 files changed, 48 insertions, 0 deletions
diff --git a/testing/mozbase/rust/mozrunner/src/path.rs b/testing/mozbase/rust/mozrunner/src/path.rs
new file mode 100644
index 0000000000..0bf1eda9ed
--- /dev/null
+++ b/testing/mozbase/rust/mozrunner/src/path.rs
@@ -0,0 +1,48 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+//! Provides utilities for searching the system path.
+
+use std::env;
+use std::path::{Path, PathBuf};
+
+#[cfg(unix)]
+fn is_executable(path: &Path) -> bool {
+    use std::fs;
+    use std::os::unix::fs::PermissionsExt;
+
+    // Permissions are a set of four 4-bit bitflags, represented by a single octal
+    // digit.  The lowest bit of each of the last three values represents the
+    // executable permission for all, group and user, repsectively.  We assume the
+    // file is executable if any of these are set.
+    match fs::metadata(path).ok() {
+        Some(meta) => meta.permissions().mode() & 0o111 != 0,
+        None => false,
+    }
+}
+
+#[cfg(not(unix))]
+fn is_executable(_: &Path) -> bool {
+    true
+}
+
+/// Determines if the path is an executable binary.  That is, if it exists, is
+/// a file, and is executable where applicable.
+pub fn is_binary(path: &Path) -> bool {
+    path.exists() && path.is_file() && is_executable(path)
+}
+
+/// Searches the system path (`PATH`) for an executable binary and returns the
+/// first match, or `None` if not found.
+pub fn find_binary(binary_name: &str) -> Option<PathBuf> {
+    env::var_os("PATH").and_then(|path_env| {
+        for mut path in env::split_paths(&path_env) {
+            path.push(binary_name);
+            if is_binary(&path) {
+                return Some(path);
+            }
+        }
+        None
+    })
+}