Create function for finding all gitignored files in a folder

Author: ExplodingCabbage

gitignore_plugin.py

@@ -0,0 +1,101 @@
+import subprocess
+import os
+
+# Used for output suppression when calling subprocess functions; see
+# http://stackoverflow.com/questions/10251391/suppressing-output-in-python-subprocess-call
+devnull = open(os.devnull, 'w')
+
+def all_ignored_files(folder):
+    """
+    Returns a list (without duplicates, in the case of weird repo-nesting) of
+    all files within the given folder that are git ignored.
+    
+    The folder itself need not be the top level of a git repo, nor even within 
+    a git repo.
+    """
+    
+    all_ignored_files = set()
+    
+    # First find all repos CONTAINED in this folder:
+    repos = set(find_git_repos(folder))
+    
+    # Then, additionally, if this folder is itself contained within a repo,
+    # find the .git folder of the repo containing it:
+    if is_in_git_repo(folder):
+        repos.add(parent_repo_path(folder))
+    
+    # Now we find all the ignored files in any of the above repos
+    for git_repo in repos:
+        ignored_files = list_ignored_files(git_repo)
+        all_ignored_files.update(ignored_files)
+            
+    return list(all_ignored_files)
+
+def is_in_git_repo(folder):
+    """
+    Returns true if the given folder is contained within a git repo
+    """
+    
+    exit_code = subprocess.call(
+        ["git", "rev-parse", "--is-inside-work-tree"],
+        cwd=folder,
+        stdout=devnull,
+        stderr=devnull
+    )
+    
+    return exit_code == 0
+
+def parent_repo_path(folder):
+    """
+    Takes the path to a folder contained within a git repo, and returns the parent repo.
+    """
+    
+    return subprocess.Popen(
+        ['git', 'rev-parse', '--show-toplevel'],
+        stdout=subprocess.PIPE,
+        cwd=folder
+    ).stdout.read().strip()
+
+def find_git_repos(folder):
+    """
+    Returns a list of all git repos within the given ancestor folder.
+    """
+    
+    # Command for finding git repos nicked from
+    # http://sixarm.com/about/git-how-to-find-git-repository-directories.html
+    command_output = subprocess.Popen(
+        ['find', folder, '-type', 'd', '-name', '.git'],
+        stdout=subprocess.PIPE
+    ).stdout.read()
+    
+    if command_output.isspace() or command_output == '':
+        return []
+    
+    dot_git_folders = command_output.strip().split('\n')
+    
+    return [path.replace('/.git', '') for path in dot_git_folders]
+
+def list_ignored_files(git_repo):
+    """
+    Takes the path of a git repo and lists all ignored files in the repo.
+    """
+        
+    # Trick for listing ignored files nicked from
+    # http://stackoverflow.com/a/2196755/1709587
+    command_output = subprocess.Popen(
+        ['git', 'clean', '-ndX'],
+        stdout=subprocess.PIPE,
+        cwd=git_repo
+    ).stdout.read()
+    
+    if command_output.isspace() or command_output == '':
+        return []
+       
+    lines = command_output.strip().split('\n')
+    # Each line in `lines` now looks something like:
+    # "Would remove foo/bar/yourfile.txt"
+    
+    relative_paths = [line.replace('Would remove ', '', 1) for line in lines]
+    absolute_paths = [git_repo + '/' + path for path in relative_paths]
+    
+    return absolute_paths