fix: correctly find connected USB DFU devices (#555)

Signed-off-by: Dominik Willner <th33xitus@gmail.com>

kiauh/components/klipper_firmware/firmware_utils.py

@@ -7,7 +7,15 @@
 #  This file may be distributed under the terms of the GNU GPLv3 license  #
 # ======================================================================= #
 
-from subprocess import PIPE, STDOUT, CalledProcessError, Popen, check_output, run
+from subprocess import (
+    DEVNULL,
+    PIPE,
+    STDOUT,
+    CalledProcessError,
+    Popen,
+    check_output,
+    run,
+)
 from typing import List
 
 from components.klipper import KLIPPER_DIR
@@ -32,8 +40,10 @@ def find_firmware_file() -> bool:
     f3 = "klipper.bin"
     f4 = "klipper.uf2"
     fw_file_exists: bool = (
-        target.joinpath(f1).exists() and target.joinpath(f2).exists()
-    ) or target.joinpath(f3).exists() or target.joinpath(f4).exists()
+        (target.joinpath(f1).exists() and target.joinpath(f2).exists())
+        or target.joinpath(f3).exists()
+        or target.joinpath(f4).exists()
+    )
 
     return target_exists and fw_file_exists
 
@@ -62,9 +72,13 @@ def find_uart_device() -> List[str]:
 
 def find_usb_dfu_device() -> List[str]:
     try:
-        command = '"lsusb | grep "DFU" | cut -d " " -f 6 2>/dev/null"'
-        output = check_output(command, shell=True, text=True)
-        return output.splitlines()
+        output = check_output("lsusb", shell=True, text=True, stderr=DEVNULL)
+        device_list = []
+        if output:
+            devices = output.splitlines()
+            device_list = [d.split(" ")[5] for d in devices if "DFU" in d]
+        return device_list
+
     except CalledProcessError as e:
         Logger.print_error("Unable to find a USB DFU device!")
         Logger.print_error(e, prefix=False)