added merge pdfs, fixed jpgstopdf arg issues,

pngtojpg.py

@@ -1,19 +1,42 @@
 #!/usr/bin/env python3
 from PIL import Image
 import sys
+import os
 
-if len(sys.argv) != 3:
-    print("Usage: pngtojpg <input_png_path> <output_jpg_path>")
-    sys.exit(1)
+def convert_png_to_jpg(input_path, output_path):
+    # Check if the input PNG file exists
+    if not os.path.isfile(input_path):
+        print(f"Error: The input PNG file '{input_path}' does not exist.")
+        sys.exit(1)
 
-input_path = sys.argv[1]
-output_path = sys.argv[2]
+    # Check if the output directory is writable
+    output_dir = os.path.dirname(output_path)
+    if output_dir and not os.access(output_dir, os.W_OK):
+        print(f"Error: The output directory '{output_dir}' is not writable.")
+        sys.exit(1)
 
-try:
-    img = Image.open(input_path)
-    img = img.convert("RGB")
-    img.save(output_path, "JPEG")
-    print(f"Conversion complete. Check the {output_path} file.")
-except Exception as e:
-    print(f"Error during conversion: {e}")
-    sys.exit(1)
+    try:
+        # Open the PNG image and convert it to JPG
+        img = Image.open(input_path)
+        img = img.convert("RGB")  # Ensure conversion to RGB
+        img.save(output_path, "JPEG")
+        print(f"Conversion complete. Check the '{output_path}' file.")
+    except FileNotFoundError:
+        print(f"Error: The input PNG file '{input_path}' was not found.")
+        sys.exit(1)
+    except PermissionError:
+        print(f"Error: Permission denied when writing to '{output_path}'.")
+        sys.exit(1)
+    except Exception as e:
+        print(f"An unexpected error occurred during conversion: {e}")
+        sys.exit(1)
+
+if __name__ == "__main__":
+    if len(sys.argv) != 3:
+        print("Usage: pngtojpg <input_png_path> <output_jpg_path>")
+        sys.exit(1)
+
+    input_path = sys.argv[1]
+    output_path = sys.argv[2]
+
+    convert_png_to_jpg(input_path, output_path)