Index: src/OFTarArchive.m
==================================================================
--- src/OFTarArchive.m
+++ src/OFTarArchive.m
@@ -293,10 +293,13 @@
 	return [[_lastReturnedStream retain] autorelease];
 }
 
 - (void)close
 {
+	if (_stream == nil)
+		return;
+
 	[_lastReturnedStream close];
 	[_lastReturnedStream release];
 	_lastReturnedStream = nil;
 
 	if (_mode == OF_TAR_ARCHIVE_MODE_WRITE ||
@@ -475,10 +478,13 @@
 	return [_stream fileDescriptorForWriting];
 }
 
 - (void)close
 {
+	if (_stream == nil)
+		return;
+
 	uint64_t remainder = 512 - [_entry size] % 512;
 
 	if (_toWrite > 0)
 		@throw [OFTruncatedDataException exception];
 

Index: utils/ofzip/OFZIP.m
==================================================================
--- utils/ofzip/OFZIP.m
+++ utils/ofzip/OFZIP.m
@@ -274,16 +274,35 @@
 	if (outputDir != nil)
 		[[OFFileManager defaultManager]
 		    changeCurrentDirectoryPath: outputDir];
 
 	switch (mode) {
+	case 'a':
+	case 'c':
+		if ([remainingArguments count] < 1)
+			help(of_stderr, false, 1);
+
+		files = [remainingArguments objectsInRange:
+		    of_range(1, [remainingArguments count] - 1)];
+
+		[archive addFiles: files];
+		break;
 	case 'l':
 		if ([remainingArguments count] != 1)
 			help(of_stderr, false, 1);
 
 		[archive listFiles];
 		break;
+	case 'p':
+		if ([remainingArguments count] < 1)
+			help(of_stderr, false, 1);
+
+		files = [remainingArguments objectsInRange:
+		    of_range(1, [remainingArguments count] - 1)];
+
+		[archive printFiles: files];
+		break;
 	case 'x':
 		if ([remainingArguments count] < 1)
 			help(of_stderr, false, 1);
 
 		files = [remainingArguments objectsInRange:
@@ -314,19 +333,10 @@
 			    @"error", error)];
 			_exitStatus = 1;
 		}
 
 		break;
-	case 'p':
-		if ([remainingArguments count] < 1)
-			help(of_stderr, false, 1);
-
-		files = [remainingArguments objectsInRange:
-		    of_range(1, [remainingArguments count] - 1)];
-
-		[archive printFiles: files];
-		break;
 	default:
 		help(of_stderr, true, 1);
 		break;
 	}
 

Index: utils/ofzip/TarArchive.m
==================================================================
--- utils/ofzip/TarArchive.m
+++ utils/ofzip/TarArchive.m
@@ -424,6 +424,119 @@
 		    @"File %[file] is not in the archive!",
 		    @"file", file)];
 		app->_exitStatus = 1;
 	}
 }
+
+- (void)addFiles: (OFArray OF_GENERIC(OFString *) *)files
+{
+	OFFileManager *fileManager = [OFFileManager defaultManager];
+
+	if ([files count] < 1) {
+		[of_stderr writeLine: OF_LOCALIZED(@"add_no_file_specified",
+		    @"Need one or more files to add!")];
+		app->_exitStatus = 1;
+		return;
+	}
+
+	for (OFString *fileName in files) {
+		void *pool = objc_autoreleasePoolPush();
+		OFMutableTarArchiveEntry *entry;
+		OFStream *output;
+
+		if (app->_outputLevel >= 0)
+			[of_stdout writeString: OF_LOCALIZED(@"adding_file",
+			    @"Adding %[file]...",
+			    @"file", fileName)];
+
+		entry = [OFMutableTarArchiveEntry entryWithFileName: fileName];
+
+#ifdef OF_FILE_MANAGER_SUPPORTS_PERMISSIONS
+		[entry setMode:
+		    [fileManager permissionsOfItemAtPath: fileName]];
+#endif
+		[entry setSize: [fileManager sizeOfFileAtPath: fileName]];
+		[entry setModificationDate:
+		    [fileManager modificationTimeOfItemAtPath: fileName]];
+
+#ifdef OF_FILE_MANAGER_SUPPORTS_OWNER
+		OFString *owner, *group;
+		[fileManager getOwner: &owner
+				group: &group
+			 ofItemAtPath: fileName];
+		[entry setOwner: owner];
+		[entry setGroup: group];
+#endif
+
+		if ([fileManager fileExistsAtPath: fileName])
+			[entry setType: OF_TAR_ARCHIVE_ENTRY_TYPE_FILE];
+		else if ([fileManager directoryExistsAtPath: fileName]) {
+			[entry setType: OF_TAR_ARCHIVE_ENTRY_TYPE_DIRECTORY];
+			[entry setSize: 0];
+		} else if ([fileManager symbolicLinkExistsAtPath: fileName]) {
+			[entry setType: OF_TAR_ARCHIVE_ENTRY_TYPE_SYMLINK];
+			[entry setTargetFileName: [fileManager
+			    destinationOfSymbolicLinkAtPath: fileName]];
+			[entry setSize: 0];
+		}
+
+		[entry makeImmutable];
+
+		output = [_archive streamForWritingEntry: entry];
+
+		if ([entry type] == OF_TAR_ARCHIVE_ENTRY_TYPE_FILE) {
+			uint64_t written = 0, size = [entry size];
+			int8_t percent = -1, newPercent;
+
+			OFFile *input = [OFFile fileWithPath: fileName
+							mode: @"r"];
+
+			while (![input isAtEndOfStream]) {
+				ssize_t length = [app
+				    copyBlockFromStream: input
+					       toStream: output
+					       fileName: fileName];
+
+				if (length < 0) {
+					app->_exitStatus = 1;
+					goto outer_loop_end;
+				}
+
+				written += length;
+				newPercent = (written == size
+				    ? 100 : (int8_t)(written * 100 / size));
+
+				if (app->_outputLevel >= 0 &&
+				    percent != newPercent) {
+					OFString *percentString;
+
+					percent = newPercent;
+					percentString = [OFString
+					    stringWithFormat: @"%3u", percent];
+
+					[of_stdout writeString: @"\r"];
+					[of_stdout writeString: OF_LOCALIZED(
+					    @"adding_file_percent",
+					    @"Adding %[file]... %[percent]%",
+					    @"file", fileName,
+					    @"percent", percentString)];
+				}
+			}
+		}
+
+		if (app->_outputLevel >= 0) {
+			[of_stdout writeString: @"\r"];
+			[of_stdout writeLine: OF_LOCALIZED(
+			    @"adding_file_done",
+			    @"Adding %[file]... done",
+			    @"file", fileName)];
+		}
+
+		[output close];
+
+outer_loop_end:
+		objc_autoreleasePoolPop(pool);
+	}
+
+	[_archive close];
+}
 @end

Index: utils/ofzip/lang/de.json
==================================================================
--- utils/ofzip/lang/de.json
+++ utils/ofzip/lang/de.json
@@ -88,7 +88,13 @@
     "list_comment": "Kommentar: %[comment]",
     "refusing_to_extract_file": "Verweigere Entpacken von %[file]!",
     "file_not_in_archive": "Datei %[file] ist nicht im Archiv!",
     "print_no_file_specified": [
         "Benötige eine oder mehrere Dateien zum Ausgeben!"
-    ]
+    ],
+    "add_no_file_specified": [
+        "Benötige eine oder mehrere Dateien zum Hinzufügen!"
+    ],
+    "adding_file": "Füge %[file] hinzu...",
+    "adding_file_percent": "Füge %[file] hinzu... %[percent]%",
+    "adding_file_done": "Füge %[file] hinzu... fertig"
 }