htsworkflow/util/mount.py

   1 """
   2 Utilities for working with unix-style mounts.
   3 """
   4 import os
   5 import subprocess
   6
   7 def list_mount_points():
   8     """
   9     Return list of current mount points
  10
  11     Note: unix-like OS specific
  12     """
  13     mount_points = []
  14     likely_locations = ['/sbin/mount', '/bin/mount']
  15     for mount in likely_locations:
  16         if os.path.exists(mount):
  17             p = subprocess.Popen(mount, stdout=subprocess.PIPE)
  18             p.wait()
  19             for l in p.stdout.readlines():
  20                 rec = l.split()
  21                 device = rec[0]
  22                 mount_point = rec[2]
  23                 assert rec[1] == 'on'
  24                 # looking at the output of mount on linux, osx, and
  25                 # sunos, the first 3 elements are always the same
  26                 # devicename on path
  27                 # everything after that displays the attributes
  28                 # of the mount points in wildly differing formats
  29                 mount_points.append(mount_point)
  30             return mount_points
  31     else:
  32         raise RuntimeError("Couldn't find a mount executable")
  33
  34 def is_mounted(point_to_check):
  35     """
  36     Return true if argument exactly matches a current mount point.
  37     """
  38     for mount_point in list_mount_points():
  39         if point_to_check == mount_point:
  40             return True
  41     else:
  42         return False
  43
  44 def find_mount_point_for(pathname):
  45     """
  46     Find the deepest mount point pathname is located on
  47     """
  48     realpath = os.path.realpath(pathname)
  49     mount_points = list_mount_points()
  50
  51     prefixes = set()
  52     for current_mount in mount_points:
  53         cp = os.path.commonprefix([current_mount, realpath])
  54         prefixes.add((len(cp), cp))
  55
  56     prefixes = list(prefixes)
  57     prefixes.sort()
  58     if len(prefixes) == 0:
  59         return None
  60     else:
  61         print prefixes
  62         # return longest common prefix
  63         return prefixes[-1][1]
  64
  65