-# $Id$
-# $URL$
-
"""A few things that didn't seem to fit anywhere else."""
-import os
+import os, os.path
import pwd
import tempfile
import fcntl
import errno
import threading
import subprocess
+import shutil
import logger
os.setsid()
if os.fork() != 0: os._exit(0)
os.chdir('/')
- os.umask(0)
+ os.umask(0022)
devnull = os.open(os.devnull, os.O_RDWR)
os.dup2(devnull, 0)
# xxx fixme - this is just to make sure that nothing gets stupidly lost - should use devnull
####################
# manage files
def pid_file():
- """We use a pid file to ensure that only one copy of NM is running at a given time. If successful, this function will write a pid file containing the pid of the current process. The return value is the pid of the other running process, or None otherwise."""
+ """We use a pid file to ensure that only one copy of NM is running at a given time.
+If successful, this function will write a pid file containing the pid of the current process.
+The return value is the pid of the other running process, or None otherwise."""
other_pid = None
if os.access(PID_FILE, os.F_OK): # check for a pid file
handle = open(PID_FILE) # pid file exists, read it
def write_file(filename, do_write, **kw_args):
"""Write file <filename> atomically by opening a temporary file, using <do_write> to write that file, and then renaming the temporary file."""
- os.rename(write_temp_file(do_write, **kw_args), filename)
+ shutil.move(write_temp_file(do_write, **kw_args), filename)
def write_temp_file(do_write, mode=None, uidgid=None):
fd, temporary_filename = tempfile.mkstemp()
return temporary_filename
# replace a target file with a new contents - checks for changes
-# return True if a change occurred, in which case
-# chown/chmod settings should be taken care of
-def replace_file_with_string (target, new_contents):
+# can handle chmod if requested
+# can also remove resulting file if contents are void, if requested
+# performs atomically:
+# writes in a tmp file, which is then renamed (from sliverauth originally)
+# returns True if a change occurred, or the file is deleted
+def replace_file_with_string (target, new_contents, chmod=None, remove_if_empty=False):
try:
current=file(target).read()
except:
current=""
- # xxx if verbose, report diffs...
if current==new_contents:
+ # if turns out to be an empty string, and remove_if_empty is set,
+ # then make sure to trash the file if it exists
+ if remove_if_empty and not new_contents and os.path.isfile(target):
+ logger.verbose("tools.replace_file_with_string: removing file %s"%target)
+ try: os.unlink(target)
+ finally: return True
return False
- # overwrite target file
- f=file(target,'w')
- f.write(new_contents)
- f.close()
+ # overwrite target file: create a temp in the same directory
+ path=os.path.dirname(target) or '.'
+ fd, name = tempfile.mkstemp('','repl',path)
+ os.write(fd,new_contents)
+ os.close(fd)
+ if os.path.exists(target):
+ os.unlink(target)
+ shutil.move(name,target)
+ if chmod: os.chmod(target,chmod)
return True
-# not needed yet - should that unlink the new file ?
-#def replace_file_with_file (target, new):
-# return replace_file_with_string (target, file(new).read())
####################
# utilities functions to get (cached) information from the node