Merge pull request #40 from xylar/add_permissions_module

Add a module for updating permissions on directories

mache/permissions.py

@@ -0,0 +1,142 @@
+import os
+import stat
+import grp
+import progressbar
+
+
+def update_permissions(base_paths, group, show_progress=True,
+                       group_writable=False, other_readable=True):
+    """
+    Update the group that a directory belongs to along with the "group" and
+    "other" permissions for the directory
+
+    Parameters
+    ----------
+    base_paths : str or list
+        The base path(s) to recursively update permissions on
+
+    group : str
+        The name of the group the contents of ``base_paths`` should belong to
+
+    show_progress : bool, optional
+        Whether to show a progress bar
+
+    group_writable : bool, optional
+        Whether to allow group write permissions
+
+    other_readable : bool, optional
+        Whether to allow world read (and, where appropriate, execute)
+        permissions
+    """
+
+    if isinstance(base_paths, str):
+        directories = [base_paths]
+    else:
+        directories = base_paths
+
+    new_uid = os.getuid()
+    new_gid = grp.getgrnam(group).gr_gid
+
+    read_write_perm = stat.S_IRUSR | stat.S_IWUSR | stat.S_IRGRP
+    exec_perm = (stat.S_IRUSR | stat.S_IWUSR | stat.S_IXUSR |
+                 stat.S_IRGRP | stat.S_IXGRP)
+
+    if group_writable:
+        read_write_perm = read_write_perm | stat.S_IWGRP
+        exec_perm = exec_perm | stat.S_IWGRP
+    if other_readable:
+        read_write_perm = read_write_perm | stat.S_IROTH
+        exec_perm = exec_perm | stat.S_IROTH | stat.S_IXOTH
+
+    mask = stat.S_IRWXU | stat.S_IRWXG | stat.S_IRWXO
+
+    # first the base directories that don't seem to be included in
+    # os.walk()
+    for directory in directories:
+        try:
+            dir_stat = os.stat(directory)
+        except OSError:
+            continue
+
+        perm = dir_stat.st_mode & mask
+
+        if perm == exec_perm and dir_stat.st_uid == new_uid and \
+                dir_stat.st_gid == new_gid:
+            continue
+
+        try:
+            os.chown(directory, new_uid, new_gid)
+            os.chmod(directory, exec_perm)
+        except OSError:
+            continue
+
+    files_and_dirs = []
+    for base in directories:
+        for root, dirs, files in os.walk(base):
+            files_and_dirs.extend(dirs)
+            files_and_dirs.extend(files)
+
+    if show_progress:
+        widgets = [progressbar.Percentage(), ' ', progressbar.Bar(),
+                   ' ', progressbar.ETA()]
+        bar = progressbar.ProgressBar(widgets=widgets,
+                                      maxval=len(files_and_dirs),
+                                      maxerror=False).start()
+    else:
+        bar = None
+    progress = 0
+    for base in directories:
+        for root, dirs, files in os.walk(base):
+            for directory in dirs:
+                progress += 1
+                if show_progress:
+                    bar.update(progress)
+
+                directory = os.path.join(root, directory)
+
+                try:
+                    dir_stat = os.stat(directory)
+                except OSError:
+                    continue
+
+                perm = dir_stat.st_mode & mask
+
+                if perm == exec_perm and dir_stat.st_uid == new_uid and \
+                        dir_stat.st_gid == new_gid:
+                    continue
+
+                try:
+                    os.chown(directory, new_uid, new_gid)
+                    os.chmod(directory, exec_perm)
+                except OSError:
+                    continue
+
+            for file_name in files:
+                progress += 1
+                bar.update(progress)
+                file_name = os.path.join(root, file_name)
+                try:
+                    file_stat = os.stat(file_name)
+                except OSError:
+                    continue
+
+                perm = file_stat.st_mode & mask
+
+                if perm & stat.S_IXUSR:
+                    # executable, so make sure others can execute it
+                    new_perm = exec_perm
+                else:
+                    new_perm = read_write_perm
+
+                if perm == new_perm and file_stat.st_uid == new_uid and \
+                        file_stat.st_gid == new_gid:
+                    continue
+
+                try:
+                    os.chown(file_name, new_uid, new_gid)
+                    os.chmod(file_name, new_perm)
+                except OSError:
+                    continue
+
+    if show_progress:
+        bar.finish()