--- a/compare_locales/paths.py
+++ b/compare_locales/paths.py
@@ -263,17 +263,17 @@ class ProjectConfig(object):
             key = key[3:]
         else:
             key = re.escape(key) + '$'
         rule['key'] = re.compile(key)
         yield rule
 
 
 class ProjectFiles(object):
-    '''Iterator object to get all files and tests for a locale and a
+    '''Iterable object to get all files and tests for a locale and a
     list of ProjectConfigs.
     '''
     def __init__(self, locale, projects, mergebase=None):
         self.locale = locale
         self.matchers = []
         self.mergebase = mergebase
         configs = []
         for project in projects:
@@ -370,16 +370,41 @@ class ProjectFiles(object):
                 yield base
             return
         for d, dirs, files in os.walk(base):
             for f in files:
                 p = mozpath.join(d, f)
                 if matcher.match(p):
                     yield p
 
+    def match(self, path):
+        '''Return the tuple of l10n_path, reference, mergepath, tests
+        if the given path matches any config, otherwise None.
+
+        This routine doesn't check that the files actually exist.
+        '''
+        for matchers in self.matchers:
+            matcher = matchers['l10n']
+            if matcher.match(path):
+                ref = merge = None
+                if 'reference' in matchers:
+                    ref = matcher.sub(matchers['reference'], path)
+                if 'merge' in matchers:
+                    merge = matcher.sub(matchers['merge'], path)
+                return path, ref, merge, matchers.get('test')
+            if 'reference' not in matchers:
+                continue
+            matcher = matchers['reference']
+            if matcher.match(path):
+                merge = None
+                l10n = matcher.sub(matchers['l10n'], path)
+                if 'merge' in matchers:
+                    merge = matcher.sub(matchers['merge'], path)
+                return l10n, path, merge, matchers.get('test')
+
 
 class ConfigNotFound(EnvironmentError):
     def __init__(self, path):
         super(ConfigNotFound, self).__init__(
             errno.ENOENT,
             'Configuration file not found',
             path)
 

--- a/compare_locales/tests/test_paths.py
+++ b/compare_locales/tests/test_paths.py
@@ -317,20 +317,27 @@ class TestProjectPaths(unittest.TestCase
             '/tmp/fr/': [
                 'good.ftl',
                 'not/subdir/bad.ftl'
             ],
         }
         files = MockProjectFiles(mocks, 'de', [cfg])
         self.assertListEqual(
             list(files), [('/tmp/de/good.ftl', None, None, set())])
+        self.assertTupleEqual(
+            files.match('/tmp/de/something.ftl'),
+            ('/tmp/de/something.ftl', None, None, set()))
+        self.assertIsNone(files.match('/tmp/fr/something.ftl'))
         files = MockProjectFiles(mocks, 'de', [cfg], mergebase='merging')
         self.assertListEqual(
             list(files),
             [('/tmp/de/good.ftl', None, 'merging/de/good.ftl', set())])
+        self.assertTupleEqual(
+            files.match('/tmp/de/something.ftl'),
+            ('/tmp/de/something.ftl', None, 'merging/de/something.ftl', set()))
         # 'fr' is not in the locale list, should return no files
         files = MockProjectFiles(mocks, 'fr', [cfg])
         self.assertListEqual(list(files), [])
 
     def test_reference_path(self):
         cfg = ProjectConfig()
         cfg.locales.append('de')
         cfg.add_paths({
@@ -356,25 +363,47 @@ class TestProjectPaths(unittest.TestCase
         self.assertListEqual(
             list(files),
             [
                 ('/tmp/l10n/de/good.ftl', '/tmp/reference/good.ftl', None,
                  set()),
                 ('/tmp/l10n/de/ref.ftl', '/tmp/reference/ref.ftl', None,
                  set()),
             ])
+        self.assertTupleEqual(
+            files.match('/tmp/l10n/de/good.ftl'),
+            ('/tmp/l10n/de/good.ftl', '/tmp/reference/good.ftl', None,
+             set()),
+            )
+        self.assertTupleEqual(
+            files.match('/tmp/reference/good.ftl'),
+            ('/tmp/l10n/de/good.ftl', '/tmp/reference/good.ftl', None,
+             set()),
+            )
+        self.assertIsNone(files.match('/tmp/l10n/de/subdir/bad.ftl'))
+        self.assertIsNone(files.match('/tmp/reference/subdir/bad.ftl'))
         files = MockProjectFiles(mocks, 'de', [cfg], mergebase='merging')
         self.assertListEqual(
             list(files),
             [
                 ('/tmp/l10n/de/good.ftl', '/tmp/reference/good.ftl',
                  'merging/de/good.ftl', set()),
                 ('/tmp/l10n/de/ref.ftl', '/tmp/reference/ref.ftl',
                  'merging/de/ref.ftl', set()),
             ])
+        self.assertTupleEqual(
+            files.match('/tmp/l10n/de/good.ftl'),
+            ('/tmp/l10n/de/good.ftl', '/tmp/reference/good.ftl',
+             'merging/de/good.ftl', set()),
+            )
+        self.assertTupleEqual(
+            files.match('/tmp/reference/good.ftl'),
+            ('/tmp/l10n/de/good.ftl', '/tmp/reference/good.ftl',
+             'merging/de/good.ftl', set()),
+            )
         # 'fr' is not in the locale list, should return no files
         files = MockProjectFiles(mocks, 'fr', [cfg])
         self.assertListEqual(list(files), [])
 
     def test_partial_l10n(self):
         cfg = ProjectConfig()
         cfg.locales.extend(['de', 'fr'])
         cfg.add_paths({
@@ -401,23 +430,28 @@ class TestProjectPaths(unittest.TestCase
         }
         files = MockProjectFiles(mocks, 'de', [cfg])
         self.assertListEqual(
             list(files),
             [
                 ('/tmp/de/major/good.ftl', None, None, set()),
                 ('/tmp/de/minor/good.ftl', None, None, set()),
             ])
+        self.assertTupleEqual(
+            files.match('/tmp/de/major/some.ftl'),
+            ('/tmp/de/major/some.ftl', None, None, set()))
+        self.assertIsNone(files.match('/tmp/de/other/some.ftl'))
         # 'fr' is not in the locale list of minor, should only return major
         files = MockProjectFiles(mocks, 'fr', [cfg])
         self.assertListEqual(
             list(files),
             [
                 ('/tmp/fr/major/good.ftl', None, None, set()),
             ])
+        self.assertIsNone(files.match('/tmp/fr/minor/some.ftl'))
 
 
 class TestProjectConfig(unittest.TestCase):
     def test_expand_paths(self):
         pc = ProjectConfig()
         pc.add_environment(one="first_path")
         self.assertEqual(pc.expand('foo'), 'foo')
         self.assertEqual(pc.expand('foo{one}bar'), 'foofirst_pathbar')