#!/usr/bin/python
"""Hello World FUSE example in Python

   from http://osdir.com/ml/file-systems.fuse.devel/2006-06/msg00000.html
"""
import os, sys, stat, errno, syslog
import fuse
from fuse import Fuse
fuse.fuse_python_api = (0, 2)
HELLO = {
 'script': None,
 'path': '/hello',
 'string': 'Hello World!\n',
 'mountpoint': '/mnt/fuse/hello'
}
if len(sys.argv) and sys.argv[0] and os.path.exists(sys.argv[0]):
 HELLO['script'] = os.path.abspath(sys.argv[0])
 print >>sys.stderr, 'initialized %s' % HELLO['script']
else:
 print >>sys.stderr, 'could not initialize script properly'

class HelloStat(fuse.Stat):
 def __init__(self):
  attributes = ['st_mode', 'st_ino', 'st_dev',
   'st_nlink', 'st_uid', 'st_gid',
   'st_size', 'st_atime', 'st_mtime', 'st_ctime']
  from_source = ['st_uid', 'st_gid', 'st_atime', 'st_ctime', 'st_mtime']
  initial = dict([[attr, 0] for attr in attributes])
  try:
   if HELLO['script']:
    syslog.syslog(syslog.LOG_INFO, 'stat %s' % HELLO['script'])
    source_stat = os.stat(HELLO['script'])
    for attribute in from_source:
     initial[attribute] = getattr(source_stat, attribute, 0)
  except:
   pass
  syslog.syslog(syslog.LOG_INFO, 'initial stat: %s' % repr(initial))
  for attribute in attributes:
   setattr(self, attribute, initial[attribute])

class HelloFS(Fuse):
 def getattr(self, path):
  st = HELLO['stat'] = HelloStat()
  if path == '/':
   st.st_mode = stat.S_IFDIR | 0755
   st.st_nlink = 2
  elif path == HELLO['path']:
   st.st_mode = stat.S_IFREG | 0444
   st.st_nlink = 1
   st.st_size = len(HELLO['string'])
  else:
   return -errno.ENOENT
  return st
    
 def readdir(self, path, offset):
  ret = ['.',
         '..',
         HELLO['path'][1:]]
  for r in ret:
   yield fuse.Direntry(r)
    
 def open(self,path,flags):
  if path!=HELLO['path']:
   return -errno.ENOENT
  if (flags & 3) != os.O_RDONLY:
   return -errno.EACCES
  return 0
    
 def read(self,path,size,offset):
  if path != HELLO['path']:
   return -errno.ENOENT
  slen = len(HELLO['string'])
  if offset < slen:
   if (offset+size)>slen:
    size = slen-offset
   buf = HELLO['string'][offset:offset+size]
  else:
   buf = ''
  return buf

def main():
 usage="""
Userspace hello example


""" + Fuse.fusage
 syslog.openlog('hellofuse', syslog.LOG_PID, syslog.LOG_KERN)
 syslog.syslog(syslog.LOG_INFO, 'starting FUSE "hello world"')
 server = HelloFS(version="%prog " + fuse.__version__,
  usage=usage,
  dash_s_do='setsingle')
 server.parse(values=server, errex=1)
 server.main()

if __name__=='__main__':
 if len(sys.argv) < 2:
  sys.argv.append(HELLO['mountpoint'])
 main()