add function to extract ISO archives/images

udib/__init__.py

@@ -0,0 +1 @@
+#!/usr/bin/env python3

udib/udib.py

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+#!/usr/bin/env python3
+
+from pathlib import Path
+import subprocess
+
+def extract_iso(path_to_output_dir, path_to_input_file):
+    """Extracts the input ISO-file into the specified directory using 'bsdtar'.
+
+    Parameters
+    ----------
+    path_to_output_dir : str or pathlike object
+        Path to the directory into which the contents of the archive will be
+        extracted.
+    path_to_input_file : str or pathlike object
+        Path to the file/archive which should be extracted.
+
+    Raises
+    ------
+    RuntimeError
+        Raised if 'bsdtar' is not installed or encountered an error during the
+        extraction.
+    FileNotFoundError
+        Raised if the input file does not exist or is not a file.
+    NotADirectoryError
+        Raised if the output directory does not exist or is not a directory.
+
+    Example
+    -------
+        extract_iso("/tmp/isocontents", "/home/myuser/downloads/debian-11.iso")
+    """
+
+    path_to_output_dir = Path(path_to_output_dir)
+    path_to_input_file = Path(path_to_input_file)
+
+    # check if paths are valid
+    if not path_to_output_dir.is_dir():
+        raise NotADirectoryError(f"No such directory: '{path_to_output_dir}'.")
+    if not path_to_input_file.is_file():
+        raise FileNotFoundError(f"No such file: '{path_to_input_file}'.")
+
+    # check if 'bsdtar' is installed
+    try:
+        subprocess.run(["command", "-v", "bsdtar"], check=True)
+    except subprocess.CalledProcessError:
+        raise RuntimeError(f"Program not found in $PATH: 'bsdtar'.")
+
+    # extract file to destination
+    try:
+        subprocess.run(
+            [
+                "bsdtar",
+                "-C",
+                str(path_to_output_dir),
+                "-xf",
+                str(path_to_input_file)
+            ],
+            check=True
+        )
+    except subprocess.CalledProcessError:
+        raise RuntimeError(
+            f"An error occurred while extracting '{path_to_input_file}'."
+        )