[#945] Added another useful MT::Util function, `match_file_extension(…

…)` which makes it extremely simple to see—in a cross-platform, multibyte-safe way—whether a file ends with a particular file extension or matches one of an array of patterns representing possible extensions or extensions of interest.

Includes POD docs and ample usage examples in the unit tests.

lib/MT/Util.pm

@@ -2708,11 +2708,15 @@ sub to_json {
 }
 
 # Tested in t/99-utils.misc
+# TODO Move this to MT::FileMgr (perhaps?)
 sub file_extension {
     my $fname        = shift;
     require File::Basename;
     my @parts = split(/\./, File::Basename::basename($fname));
-    shift @parts while @parts > 1 and $parts[0] eq ''; # Skips empty dotfile element
+
+    shift @parts
+        while @parts > 1 and $parts[0] eq ''; # Skips empty dotfile element
+
     return @parts > 1 ? pop @parts : ''
 }  ## end sub file_extension
 
@@ -2762,6 +2766,18 @@ sub mime_type_extension {
 } ## end sub mime_type_extension
 
 
+# Tested in t/99-utils.misc
+# TODO Move this to MT::FileMgr (perhaps?)
+sub match_file_extension {
+    my $filename = shift;
+    my $exts     = ref $_[0] eq 'ARRAY' ? shift : [ @_ ];
+    require File::Basename;
+    my @exts     = map { m/^\./ ? qr/$_/i : qr/\.$_/i } @$exts;
+    my @ret      = File::Basename::fileparse( $filename, @exts );
+    return $ret[2] if @ret;
+} ## end sub match_file_extension
+
+
 1;
 
 __END__
@@ -3040,6 +3056,23 @@ variant.
 If no extensions are found for the specified MIME type, the function will
 return an empty array;
 
+=head2 match_file_extension( $file, \@patterns )
+
+This function compares a file name (with or without preceding path) against an
+array of one or more patterns which represent possible file extensions or
+extensions of interest.  For example:
+
+    match_file_extension( 'file.txt',  [qw( rtf txt doc )] )  # Yields '.txt'
+    match_file_extension( 'file.php3', [qw( php[s\d]?   )] )  # Yields '.php3'
+
+If a pattern matches (case-insensitive, anchored to
+the right side of the string), the matched portion of the file name is
+returned. If no match is found, the function returns an empty string.
+
+The array of patterns can be supplied either as an array reference or an array. 
+
+See t/99-utils-misc.t for far more examples of usage.
+
 =head2 addbin
 
 =head2 archive_file_for

t/99-utils-misc.t

@@ -7,7 +7,7 @@ use strict;
 use warnings;
 
 use lib 't/lib', 'lib', 'extlib';
-use Test::More tests => 3;
+use Test::More tests => 4;
 
 use MT;
 use MT::Util;
@@ -181,6 +181,44 @@ subtest "mime_type_extension()" => sub {
     }
 };
 
+subtest "match_file_extension()" => sub {
+    my @tests = (
+        # FILE NAME         EXTENSION SEARCH ARRAY            EXPECTED RESULT
+        [ 'file.txt'     => ['txt']                        => '.txt'      ],
+        [ 'file.txt'     => [ qw( text doc rtf txt md ) ]  => '.txt'      ],
+        [ 'file.js'      => [ qw( html js php ) ]          => '.js'       ],
+        [ 'file.json'    => [ qw( html js php ) ]          => ''          ],
+        [ 'file.js'      => [ qw( html json php ) ]        => ''          ],
+        [ 'file.json'    => [ qw( html js.* php ) ]        => '.json'     ],
+        [ 'file.js'      => [ qw( html js.* php ) ]        => '.js'       ],
+        [ 'file.php'     => [ qw( html js.* php[s\d]? ) ]  => '.php'      ],
+        [ 'file.php3'    => [ qw( html js.* php[s\d]? ) ]  => '.php3'     ],
+        [ 'file.php5'    => [ qw( html js.* php[s\d]? ) ]  => '.php5'     ],
+        [ 'file.phps'    => [ qw( html js.* php[s\d]? ) ]  => '.phps'     ],
+        [ '.htaccess'    => [ qw( cnf conf htaccess ) ]    => '.htaccess' ],
+        [ '.my.cnf'      => [ qw( cnf conf htaccess ) ]    => '.cnf'      ],
+        [ 'file.tar.gz'  => [ qw( Z bz2 gz zip ) ]         => '.gz'       ],
+        [ 'file.tar.gz'  => [ qw( Z bz2 tar zip ) ]        => ''          ],
+        [ 'file.tar.gz'  => [ qw( Z bz2 tar\.gz zip ) ]    => '.tar.gz'   ],
+        [ '.'            => [ qw( cgi txt pl ) ]           => ''          ],
+        [ '..'           => [ qw( cgi txt pl ) ]           => ''          ],
+    );
+    plan tests => @tests * 2;
+
+    foreach my $test ( @tests ) {
+        my ($fname, $exts, $expected) = @$test;
+        foreach my $path ( '', '/tmp/' ) {
+            $fname = $path . $fname;
+            is(
+                MT::Util::match_file_extension( $fname, $exts ),
+                $expected,
+                sprintf( "Matching '%s' against (%s) returns '%s'",
+                        $fname, join(', ', @$exts), $expected )
+            );
+        }
+    }
+};
+
 1;
 __END__