feat: add experimental manga support

fastanime/cli/utils/feh.py

@@ -0,0 +1,12 @@
+import shutil
+import subprocess
+from sys import exit
+
+
+def feh_manga_viewer(image_links: list[str], window_title: str):
+    FEH_EXECUTABLE = shutil.which("feh")
+    if not FEH_EXECUTABLE:
+        print("feh not found")
+        exit(1)
+    commands = [FEH_EXECUTABLE, *image_links, "--title", window_title]
+    subprocess.run(commands)