diff --git a/my/core/common.py b/my/core/common.py
index fba7efb..92806d2 100644
--- a/my/core/common.py
+++ b/my/core/common.py
@@ -163,12 +163,6 @@ from .logging import setup_logger, LazyLogger
 Paths = Union[Sequence[PathIsh], PathIsh]
 
 
-def _is_compressed(p: Path) -> bool:
-    # todo kinda lame way for now.. use mime ideally?
-    # should cooperate with kompress.kopen?
-    return p.suffix in {'.xz', '.lz4', '.zstd'}
-
-
 DEFAULT_GLOB = '*'
 def get_files(
         pp: Paths,
@@ -233,8 +227,8 @@ def get_files(
         traceback.print_stack()
 
     if guess_compression:
-        from .kompress import CPath
-        paths = [CPath(p) if _is_compressed(p) else p for p in paths]
+        from .kompress import CPath, is_compressed
+        paths = [CPath(p) if is_compressed(p) else p for p in paths]
     return tuple(paths)
 
 
diff --git a/my/core/kompress.py b/my/core/kompress.py
index 4fa2840..a9a8576 100644
--- a/my/core/kompress.py
+++ b/my/core/kompress.py
@@ -9,6 +9,20 @@ import io
 PathIsh = Union[Path, str]
 
 
+class Ext:
+    xz    = '.xz'
+    zip   = '.zip'
+    lz4   = '.lz4'
+    zstd  = '.zstd'
+    targz = '.tar.gz'
+
+
+def is_compressed(p: Path) -> bool:
+    # todo kinda lame way for now.. use mime ideally?
+    # should cooperate with kompress.kopen?
+    return any(p.name.endswith(ext) for ext in {Ext.xz, Ext.zip, Ext.lz4, Ext.zstd, Ext.targz})
+
+
 def _zstd_open(path: Path, *args, **kwargs) -> IO[str]:
     import zstandard as zstd # type: ignore
     fh = path.open('rb')
@@ -25,15 +39,15 @@ def kopen(path: PathIsh, *args, mode: str='rt', **kwargs) -> IO[str]:
     kwargs['encoding'] = encoding
 
     pp = Path(path)
-    suf = pp.suffix
-    if suf in {'.xz'}:
+    name = pp.name
+    if name.endswith(Ext.xz):
         import lzma
         r = lzma.open(pp, mode, *args, **kwargs)
         # should only happen for binary mode?
         # file:///usr/share/doc/python3/html/library/lzma.html?highlight=lzma#lzma.open
         assert not isinstance(r, lzma.LZMAFile), r
         return r
-    elif suf in {'.zip'}:
+    elif name.endswith(Ext.zip):
         # eh. this behaviour is a bit dodgy...
         from zipfile import ZipFile
         zfile = ZipFile(pp)
@@ -49,11 +63,18 @@ def kopen(path: PathIsh, *args, mode: str='rt', **kwargs) -> IO[str]:
         # TODO pass all kwargs here??
         # todo 'expected "BinaryIO"'??
         return io.TextIOWrapper(ifile, encoding=encoding) # type: ignore[arg-type]
-    elif suf in {'.lz4'}:
+    elif name.endswith(Ext.lz4):
         import lz4.frame # type: ignore
         return lz4.frame.open(str(pp), mode, *args, **kwargs)
-    elif suf in {'.zstd'}:
+    elif name.endswith(Ext.zstd):
         return _zstd_open(pp, mode, *args, **kwargs)
+    elif name.endswith(Ext.targz):
+        import tarfile
+        # FIXME pass mode?
+        tf = tarfile.open(pp)
+        # TODO pass encoding?
+        x = tf.extractfile(*args); assert x is not None
+        return x  #  type: ignore[return-value]
     else:
         return pp.open(mode, *args, **kwargs)