1 files changed, 147 insertions, 148 deletions
diff --git a/bitbake/lib/bb/daemonize.py b/bitbake/lib/bb/daemonize.py
index 1a8bb379f4..a944af2238 100644
--- a/bitbake/lib/bb/daemonize.py
+++ b/bitbake/lib/bb/daemonize.py
@@ -3,17 +3,17 @@ Python Deamonizing helper
 Configurable daemon behaviors:
-   1.) The current working directory set to the "/" directory.
+    1.) The current working directory set to the "/" directory.
-   2.) The current file creation mode mask set to 0.
+    2.) The current file creation mode mask set to 0.
-   3.) Close all open files (1024). 
+    3.) Close all open files (1024). 
-   4.) Redirect standard I/O streams to "/dev/null".
+    4.) Redirect standard I/O streams to "/dev/null".
 A failed call to fork() now raises an exception.
 References:
-   1) Advanced Programming in the Unix Environment: W. Richard Stevens
+    1) Advanced Programming in the Unix Environment: W. Richard Stevens
-   2) Unix Programming Frequently Asked Questions:
+    2) Unix Programming Frequently Asked Questions:
-         http://www.erlenstar.demon.co.uk/unix/faq_toc.html
+            http://www.erlenstar.demon.co.uk/unix/faq_toc.html
 Modified to allow a function to be daemonized and return for 
 bitbake use by Richard Purdie
@@ -24,8 +24,8 @@ __copyright__ = "Copyright (C) 2005 Chad J. Schroeder"
 __version__ = "0.2"
 # Standard Python modules.
-import os               # Miscellaneous OS interfaces.
+import os                    # Miscellaneous OS interfaces.
-import sys              # System-specific parameters and functions.
+import sys                  # System-specific parameters and functions.
 # Default daemon parameters.
 # File mode creation mask of the daemon.
@@ -37,155 +37,154 @@ MAXFD = 1024
 # The standard I/O file descriptors are redirected to /dev/null by default.
 if (hasattr(os, "devnull")):
-   REDIRECT_TO = os.devnull
+    REDIRECT_TO = os.devnull
 else:
-   REDIRECT_TO = "/dev/null"
+    REDIRECT_TO = "/dev/null"
 def createDaemon(function, logfile):
-   """
+    """
-   Detach a process from the controlling terminal and run it in the
+    Detach a process from the controlling terminal and run it in the
-   background as a daemon, returning control to the caller.
+    background as a daemon, returning control to the caller.
-   """
+    """
-   try:
+    try:
-      # Fork a child process so the parent can exit.  This returns control to
+        # Fork a child process so the parent can exit.  This returns control to
-      # the command-line or shell.  It also guarantees that the child will not
+        # the command-line or shell.  It also guarantees that the child will not
-      # be a process group leader, since the child receives a new process ID
+        # be a process group leader, since the child receives a new process ID
-      # and inherits the parent's process group ID.  This step is required
+        # and inherits the parent's process group ID.  This step is required
-      # to insure that the next call to os.setsid is successful.
+        # to insure that the next call to os.setsid is successful.
-      pid = os.fork()
+        pid = os.fork()
-   except OSError, e:
+    except OSError, e:
-      raise Exception, "%s [%d]" % (e.strerror, e.errno)
+        raise Exception, "%s [%d]" % (e.strerror, e.errno)
-   if (pid == 0):       # The first child.
+    if (pid == 0):      # The first child.
-      # To become the session leader of this new session and the process group
+        # To become the session leader of this new session and the process group
-      # leader of the new process group, we call os.setsid().  The process is
+        # leader of the new process group, we call os.setsid().  The process is
-      # also guaranteed not to have a controlling terminal.
+        # also guaranteed not to have a controlling terminal.
-      os.setsid()
+        os.setsid()
-      # Is ignoring SIGHUP necessary?
+        # Is ignoring SIGHUP necessary?
-      #
+        #
-      # It's often suggested that the SIGHUP signal should be ignored before
+        # It's often suggested that the SIGHUP signal should be ignored before
-      # the second fork to avoid premature termination of the process.  The
+        # the second fork to avoid premature termination of the process.  The
-      # reason is that when the first child terminates, all processes, e.g.
+        # reason is that when the first child terminates, all processes, e.g.
-      # the second child, in the orphaned group will be sent a SIGHUP.
+        # the second child, in the orphaned group will be sent a SIGHUP.
-      #
+        #
-      # "However, as part of the session management system, there are exactly
+        # "However, as part of the session management system, there are exactly
-      # two cases where SIGHUP is sent on the death of a process:
+        # two cases where SIGHUP is sent on the death of a process:
-      #
+        #
-      #   1) When the process that dies is the session leader of a session that
+        #    1) When the process that dies is the session leader of a session that
-      #      is attached to a terminal device, SIGHUP is sent to all processes
+        #        is attached to a terminal device, SIGHUP is sent to all processes
-      #      in the foreground process group of that terminal device.
+        #        in the foreground process group of that terminal device.
-      #   2) When the death of a process causes a process group to become
+        #    2) When the death of a process causes a process group to become
-      #      orphaned, and one or more processes in the orphaned group are
+        #        orphaned, and one or more processes in the orphaned group are
-      #      stopped, then SIGHUP and SIGCONT are sent to all members of the
+        #        stopped, then SIGHUP and SIGCONT are sent to all members of the
-      #      orphaned group." [2]
+        #        orphaned group." [2]
-      #
+        #
-      # The first case can be ignored since the child is guaranteed not to have
+        # The first case can be ignored since the child is guaranteed not to have
-      # a controlling terminal.  The second case isn't so easy to dismiss.
+        # a controlling terminal.  The second case isn't so easy to dismiss.
-      # The process group is orphaned when the first child terminates and
+        # The process group is orphaned when the first child terminates and
-      # POSIX.1 requires that every STOPPED process in an orphaned process
+        # POSIX.1 requires that every STOPPED process in an orphaned process
-      # group be sent a SIGHUP signal followed by a SIGCONT signal.  Since the
+        # group be sent a SIGHUP signal followed by a SIGCONT signal.  Since the
-      # second child is not STOPPED though, we can safely forego ignoring the
+        # second child is not STOPPED though, we can safely forego ignoring the
-      # SIGHUP signal.  In any case, there are no ill-effects if it is ignored.
+        # SIGHUP signal.  In any case, there are no ill-effects if it is ignored.
-      #
+        #
-      # import signal           # Set handlers for asynchronous events.
+        # import signal              # Set handlers for asynchronous events.
-      # signal.signal(signal.SIGHUP, signal.SIG_IGN)
+        # signal.signal(signal.SIGHUP, signal.SIG_IGN)
-      try:
+        try:
-         # Fork a second child and exit immediately to prevent zombies.  This
+            # Fork a second child and exit immediately to prevent zombies.  This
-         # causes the second child process to be orphaned, making the init
+            # causes the second child process to be orphaned, making the init
-         # process responsible for its cleanup.  And, since the first child is
+            # process responsible for its cleanup.  And, since the first child is
-         # a session leader without a controlling terminal, it's possible for
+            # a session leader without a controlling terminal, it's possible for
-         # it to acquire one by opening a terminal in the future (System V-
+            # it to acquire one by opening a terminal in the future (System V-
-         # based systems).  This second fork guarantees that the child is no
+            # based systems).  This second fork guarantees that the child is no
-         # longer a session leader, preventing the daemon from ever acquiring
+            # longer a session leader, preventing the daemon from ever acquiring
-         # a controlling terminal.
+            # a controlling terminal.
-         pid = os.fork()        # Fork a second child.
+            pid = os.fork()     # Fork a second child.
-      except OSError, e:
+        except OSError, e:
-         raise Exception, "%s [%d]" % (e.strerror, e.errno)
+            raise Exception, "%s [%d]" % (e.strerror, e.errno)
-      if (pid == 0):    # The second child.
+        if (pid == 0):  # The second child.
-         # We probably don't want the file mode creation mask inherited from
+            # We probably don't want the file mode creation mask inherited from
-         # the parent, so we give the child complete control over permissions.
+            # the parent, so we give the child complete control over permissions.
-         if UMASK is not None:
+            if UMASK is not None:
-             os.umask(UMASK)
+                os.umask(UMASK)
-      else:
+        else:
-         # Parent (the first child) of the second child.
+            # Parent (the first child) of the second child.
-         os._exit(0)
+            os._exit(0)
-   else:
+    else:
-      # exit() or _exit()?
+        # exit() or _exit()?
-      # _exit is like exit(), but it doesn't call any functions registered
+        # _exit is like exit(), but it doesn't call any functions registered
-      # with atexit (and on_exit) or any registered signal handlers.  It also
+        # with atexit (and on_exit) or any registered signal handlers.  It also
-      # closes any open file descriptors.  Using exit() may cause all stdio
+        # closes any open file descriptors.  Using exit() may cause all stdio
-      # streams to be flushed twice and any temporary files may be unexpectedly
+        # streams to be flushed twice and any temporary files may be unexpectedly
-      # removed.  It's therefore recommended that child branches of a fork()
+        # removed.  It's therefore recommended that child branches of a fork()
-      # and the parent branch(es) of a daemon use _exit().
+        # and the parent branch(es) of a daemon use _exit().
-      return
+        return
-   # Close all open file descriptors.  This prevents the child from keeping
+    # Close all open file descriptors.  This prevents the child from keeping
-   # open any file descriptors inherited from the parent.  There is a variety
+    # open any file descriptors inherited from the parent.  There is a variety
-   # of methods to accomplish this task.  Three are listed below.
+    # of methods to accomplish this task.  Three are listed below.
-   #
+    #
-   # Try the system configuration variable, SC_OPEN_MAX, to obtain the maximum
+    # Try the system configuration variable, SC_OPEN_MAX, to obtain the maximum
-   # number of open file descriptors to close.  If it doesn't exists, use
+    # number of open file descriptors to close.  If it doesn't exists, use
-   # the default value (configurable).
+    # the default value (configurable).
-   #
+    #
-   # try:
+    # try:
-   #    maxfd = os.sysconf("SC_OPEN_MAX")
+    #     maxfd = os.sysconf("SC_OPEN_MAX")
-   # except (AttributeError, ValueError):
+    # except (AttributeError, ValueError):
-   #    maxfd = MAXFD
+    #     maxfd = MAXFD
-   #
+    #
-   # OR
+    # OR
-   #
+    #
-   # if (os.sysconf_names.has_key("SC_OPEN_MAX")):
+    # if (os.sysconf_names.has_key("SC_OPEN_MAX")):
-   #    maxfd = os.sysconf("SC_OPEN_MAX")
+    #     maxfd = os.sysconf("SC_OPEN_MAX")
-   # else:
+    # else:
-   #    maxfd = MAXFD
+    #     maxfd = MAXFD
-   #
+    #
-   # OR
+    # OR
-   #
+    #
-   # Use the getrlimit method to retrieve the maximum file descriptor number
+    # Use the getrlimit method to retrieve the maximum file descriptor number
-   # that can be opened by this process.  If there is not limit on the
+    # that can be opened by this process.  If there is not limit on the
-   # resource, use the default value.
+    # resource, use the default value.
-   #
+    #
-   import resource              # Resource usage information.
+    import resource             # Resource usage information.
-   maxfd = resource.getrlimit(resource.RLIMIT_NOFILE)[1]
+    maxfd = resource.getrlimit(resource.RLIMIT_NOFILE)[1]
-   if (maxfd == resource.RLIM_INFINITY):
+    if (maxfd == resource.RLIM_INFINITY):
-      maxfd = MAXFD
+        maxfd = MAXFD
  
-   # Iterate through and close all file descriptors.
+    # Iterate through and close all file descriptors.
-#   for fd in range(0, maxfd):
+#    for fd in range(0, maxfd):
-#      try:
+#        try:
-#         os.close(fd)
+#            os.close(fd)
-#      except OSError:  # ERROR, fd wasn't open to begin with (ignored)
+#        except OSError:        # ERROR, fd wasn't open to begin with (ignored)
-#         pass
+#            pass
-   # Redirect the standard I/O file descriptors to the specified file.  Since
+    # Redirect the standard I/O file descriptors to the specified file.  Since
-   # the daemon has no controlling terminal, most daemons redirect stdin,
+    # the daemon has no controlling terminal, most daemons redirect stdin,
-   # stdout, and stderr to /dev/null.  This is done to prevent side-effects
+    # stdout, and stderr to /dev/null.  This is done to prevent side-effects
-   # from reads and writes to the standard I/O file descriptors.
+    # from reads and writes to the standard I/O file descriptors.
-   # This call to open is guaranteed to return the lowest file descriptor,
+    # This call to open is guaranteed to return the lowest file descriptor,
-   # which will be 0 (stdin), since it was closed above.
+    # which will be 0 (stdin), since it was closed above.
-#   os.open(REDIRECT_TO, os.O_RDWR)     # standard input (0)
+#    os.open(REDIRECT_TO, os.O_RDWR)    # standard input (0)
-   # Duplicate standard input to standard output and standard error.
+    # Duplicate standard input to standard output and standard error.
-#   os.dup2(0, 1)                       # standard output (1)
+#    os.dup2(0, 1)                      # standard output (1)
-#   os.dup2(0, 2)                       # standard error (2)
+#    os.dup2(0, 2)                      # standard error (2)
-   si = file('/dev/null', 'r')
+    si = file('/dev/null', 'r')
-   so = file(logfile, 'w')
+    so = file(logfile, 'w')
-   se = so
+    se = so
-   # Replace those fds with our own
+    # Replace those fds with our own
-   os.dup2(si.fileno(), sys.stdin.fileno())
+    os.dup2(si.fileno(), sys.stdin.fileno())
-   os.dup2(so.fileno(), sys.stdout.fileno())
+    os.dup2(so.fileno(), sys.stdout.fileno())
-   os.dup2(se.fileno(), sys.stderr.fileno())
+    os.dup2(se.fileno(), sys.stderr.fileno())
-   function()
+    function()
-   os._exit(0)
+    os._exit(0)

diff --git a/bitbake/lib/bb/daemonize.py b/bitbake/lib/bb/daemonize.py index 1a8bb379f4..a944af2238 100644 --- a/bitbake/lib/bb/daemonize.py +++ b/bitbake/lib/bb/daemonize.py
@@ -3,17 +3,17 @@ Python Deamonizing helper
3		3
4	Configurable daemon behaviors:	4	Configurable daemon behaviors:
5		5
6	1.) The current working directory set to the "/" directory.	6	1.) The current working directory set to the "/" directory.
7	2.) The current file creation mode mask set to 0.	7	2.) The current file creation mode mask set to 0.
8	3.) Close all open files (1024).	8	3.) Close all open files (1024).
9	4.) Redirect standard I/O streams to "/dev/null".	9	4.) Redirect standard I/O streams to "/dev/null".
10		10
11	A failed call to fork() now raises an exception.	11	A failed call to fork() now raises an exception.
12		12
13	References:	13	References:
14	1) Advanced Programming in the Unix Environment: W. Richard Stevens	14	1) Advanced Programming in the Unix Environment: W. Richard Stevens
15	2) Unix Programming Frequently Asked Questions:	15	2) Unix Programming Frequently Asked Questions:
16	http://www.erlenstar.demon.co.uk/unix/faq_toc.html	16	http://www.erlenstar.demon.co.uk/unix/faq_toc.html
17		17
18	Modified to allow a function to be daemonized and return for	18	Modified to allow a function to be daemonized and return for
19	bitbake use by Richard Purdie	19	bitbake use by Richard Purdie
@@ -24,8 +24,8 @@ __copyright__ = "Copyright (C) 2005 Chad J. Schroeder"
24	__version__ = "0.2"	24	__version__ = "0.2"
25		25
26	# Standard Python modules.	26	# Standard Python modules.
27	import os # Miscellaneous OS interfaces.	27	import os # Miscellaneous OS interfaces.
28	import sys # System-specific parameters and functions.	28	import sys # System-specific parameters and functions.
29		29
30	# Default daemon parameters.	30	# Default daemon parameters.
31	# File mode creation mask of the daemon.	31	# File mode creation mask of the daemon.
@@ -37,155 +37,154 @@ MAXFD = 1024
37		37
38	# The standard I/O file descriptors are redirected to /dev/null by default.	38	# The standard I/O file descriptors are redirected to /dev/null by default.
39	if (hasattr(os, "devnull")):	39	if (hasattr(os, "devnull")):
40	REDIRECT_TO = os.devnull	40	REDIRECT_TO = os.devnull
41	else:	41	else:
42	REDIRECT_TO = "/dev/null"	42	REDIRECT_TO = "/dev/null"
43		43
44	def createDaemon(function, logfile):	44	def createDaemon(function, logfile):
45	"""	45	"""
46	Detach a process from the controlling terminal and run it in the	46	Detach a process from the controlling terminal and run it in the
47	background as a daemon, returning control to the caller.	47	background as a daemon, returning control to the caller.
48	"""	48	"""
49		49
50	try:	50	try:
51	# Fork a child process so the parent can exit. This returns control to	51	# Fork a child process so the parent can exit. This returns control to
52	# the command-line or shell. It also guarantees that the child will not	52	# the command-line or shell. It also guarantees that the child will not
53	# be a process group leader, since the child receives a new process ID	53	# be a process group leader, since the child receives a new process ID
54	# and inherits the parent's process group ID. This step is required	54	# and inherits the parent's process group ID. This step is required
55	# to insure that the next call to os.setsid is successful.	55	# to insure that the next call to os.setsid is successful.
56	pid = os.fork()	56	pid = os.fork()
57	except OSError, e:	57	except OSError, e:
58	raise Exception, "%s [%d]" % (e.strerror, e.errno)	58	raise Exception, "%s [%d]" % (e.strerror, e.errno)
59		59
60	if (pid == 0): # The first child.	60	if (pid == 0): # The first child.
61	# To become the session leader of this new session and the process group	61	# To become the session leader of this new session and the process group
62	# leader of the new process group, we call os.setsid(). The process is	62	# leader of the new process group, we call os.setsid(). The process is
63	# also guaranteed not to have a controlling terminal.	63	# also guaranteed not to have a controlling terminal.
64	os.setsid()	64	os.setsid()
65		65
66	# Is ignoring SIGHUP necessary?	66	# Is ignoring SIGHUP necessary?
67	#	67	#
68	# It's often suggested that the SIGHUP signal should be ignored before	68	# It's often suggested that the SIGHUP signal should be ignored before
69	# the second fork to avoid premature termination of the process. The	69	# the second fork to avoid premature termination of the process. The
70	# reason is that when the first child terminates, all processes, e.g.	70	# reason is that when the first child terminates, all processes, e.g.
71	# the second child, in the orphaned group will be sent a SIGHUP.	71	# the second child, in the orphaned group will be sent a SIGHUP.
72	#	72	#
73	# "However, as part of the session management system, there are exactly	73	# "However, as part of the session management system, there are exactly
74	# two cases where SIGHUP is sent on the death of a process:	74	# two cases where SIGHUP is sent on the death of a process:
75	#	75	#
76	# 1) When the process that dies is the session leader of a session that	76	# 1) When the process that dies is the session leader of a session that
77	# is attached to a terminal device, SIGHUP is sent to all processes	77	# is attached to a terminal device, SIGHUP is sent to all processes
78	# in the foreground process group of that terminal device.	78	# in the foreground process group of that terminal device.
79	# 2) When the death of a process causes a process group to become	79	# 2) When the death of a process causes a process group to become
80	# orphaned, and one or more processes in the orphaned group are	80	# orphaned, and one or more processes in the orphaned group are
81	# stopped, then SIGHUP and SIGCONT are sent to all members of the	81	# stopped, then SIGHUP and SIGCONT are sent to all members of the
82	# orphaned group." [2]	82	# orphaned group." [2]
83	#	83	#
84	# The first case can be ignored since the child is guaranteed not to have	84	# The first case can be ignored since the child is guaranteed not to have
85	# a controlling terminal. The second case isn't so easy to dismiss.	85	# a controlling terminal. The second case isn't so easy to dismiss.
86	# The process group is orphaned when the first child terminates and	86	# The process group is orphaned when the first child terminates and
87	# POSIX.1 requires that every STOPPED process in an orphaned process	87	# POSIX.1 requires that every STOPPED process in an orphaned process
88	# group be sent a SIGHUP signal followed by a SIGCONT signal. Since the	88	# group be sent a SIGHUP signal followed by a SIGCONT signal. Since the
89	# second child is not STOPPED though, we can safely forego ignoring the	89	# second child is not STOPPED though, we can safely forego ignoring the
90	# SIGHUP signal. In any case, there are no ill-effects if it is ignored.	90	# SIGHUP signal. In any case, there are no ill-effects if it is ignored.
91	#	91	#
92	# import signal # Set handlers for asynchronous events.	92	# import signal # Set handlers for asynchronous events.
93	# signal.signal(signal.SIGHUP, signal.SIG_IGN)	93	# signal.signal(signal.SIGHUP, signal.SIG_IGN)
94		94
95	try:	95	try:
96	# Fork a second child and exit immediately to prevent zombies. This	96	# Fork a second child and exit immediately to prevent zombies. This
97	# causes the second child process to be orphaned, making the init	97	# causes the second child process to be orphaned, making the init
98	# process responsible for its cleanup. And, since the first child is	98	# process responsible for its cleanup. And, since the first child is
99	# a session leader without a controlling terminal, it's possible for	99	# a session leader without a controlling terminal, it's possible for
100	# it to acquire one by opening a terminal in the future (System V-	100	# it to acquire one by opening a terminal in the future (System V-
101	# based systems). This second fork guarantees that the child is no	101	# based systems). This second fork guarantees that the child is no
102	# longer a session leader, preventing the daemon from ever acquiring	102	# longer a session leader, preventing the daemon from ever acquiring
103	# a controlling terminal.	103	# a controlling terminal.
104	pid = os.fork() # Fork a second child.	104	pid = os.fork() # Fork a second child.
105	except OSError, e:	105	except OSError, e:
106	raise Exception, "%s [%d]" % (e.strerror, e.errno)	106	raise Exception, "%s [%d]" % (e.strerror, e.errno)
107		107
108	if (pid == 0): # The second child.	108	if (pid == 0): # The second child.
109	# We probably don't want the file mode creation mask inherited from	109	# We probably don't want the file mode creation mask inherited from
110	# the parent, so we give the child complete control over permissions.	110	# the parent, so we give the child complete control over permissions.
111	if UMASK is not None:	111	if UMASK is not None:
112	os.umask(UMASK)	112	os.umask(UMASK)
113	else:	113	else:
114	# Parent (the first child) of the second child.	114	# Parent (the first child) of the second child.
115	os._exit(0)	115	os._exit(0)
116	else:	116	else:
117	# exit() or _exit()?	117	# exit() or _exit()?
118	# _exit is like exit(), but it doesn't call any functions registered	118	# _exit is like exit(), but it doesn't call any functions registered
119	# with atexit (and on_exit) or any registered signal handlers. It also	119	# with atexit (and on_exit) or any registered signal handlers. It also
120	# closes any open file descriptors. Using exit() may cause all stdio	120	# closes any open file descriptors. Using exit() may cause all stdio
121	# streams to be flushed twice and any temporary files may be unexpectedly	121	# streams to be flushed twice and any temporary files may be unexpectedly
122	# removed. It's therefore recommended that child branches of a fork()	122	# removed. It's therefore recommended that child branches of a fork()
123	# and the parent branch(es) of a daemon use _exit().	123	# and the parent branch(es) of a daemon use _exit().
124	return	124	return
125		125
126	# Close all open file descriptors. This prevents the child from keeping	126	# Close all open file descriptors. This prevents the child from keeping
127	# open any file descriptors inherited from the parent. There is a variety	127	# open any file descriptors inherited from the parent. There is a variety
128	# of methods to accomplish this task. Three are listed below.	128	# of methods to accomplish this task. Three are listed below.
129	#	129	#
130	# Try the system configuration variable, SC_OPEN_MAX, to obtain the maximum	130	# Try the system configuration variable, SC_OPEN_MAX, to obtain the maximum
131	# number of open file descriptors to close. If it doesn't exists, use	131	# number of open file descriptors to close. If it doesn't exists, use
132	# the default value (configurable).	132	# the default value (configurable).
133	#	133	#
134	# try:	134	# try:
135	# maxfd = os.sysconf("SC_OPEN_MAX")	135	# maxfd = os.sysconf("SC_OPEN_MAX")
136	# except (AttributeError, ValueError):	136	# except (AttributeError, ValueError):
137	# maxfd = MAXFD	137	# maxfd = MAXFD
138	#	138	#
139	# OR	139	# OR
140	#	140	#
141	# if (os.sysconf_names.has_key("SC_OPEN_MAX")):	141	# if (os.sysconf_names.has_key("SC_OPEN_MAX")):
142	# maxfd = os.sysconf("SC_OPEN_MAX")	142	# maxfd = os.sysconf("SC_OPEN_MAX")
143	# else:	143	# else:
144	# maxfd = MAXFD	144	# maxfd = MAXFD
145	#	145	#
146	# OR	146	# OR
147	#	147	#
148	# Use the getrlimit method to retrieve the maximum file descriptor number	148	# Use the getrlimit method to retrieve the maximum file descriptor number
149	# that can be opened by this process. If there is not limit on the	149	# that can be opened by this process. If there is not limit on the
150	# resource, use the default value.	150	# resource, use the default value.
151	#	151	#
152	import resource # Resource usage information.	152	import resource # Resource usage information.
153	maxfd = resource.getrlimit(resource.RLIMIT_NOFILE)[1]	153	maxfd = resource.getrlimit(resource.RLIMIT_NOFILE)[1]
154	if (maxfd == resource.RLIM_INFINITY):	154	if (maxfd == resource.RLIM_INFINITY):
155	maxfd = MAXFD	155	maxfd = MAXFD
156		156
157	# Iterate through and close all file descriptors.	157	# Iterate through and close all file descriptors.
158	# for fd in range(0, maxfd):	158	# for fd in range(0, maxfd):
159	# try:	159	# try:
160	# os.close(fd)	160	# os.close(fd)
161	# except OSError: # ERROR, fd wasn't open to begin with (ignored)	161	# except OSError: # ERROR, fd wasn't open to begin with (ignored)
162	# pass	162	# pass
163		163
164	# Redirect the standard I/O file descriptors to the specified file. Since	164	# Redirect the standard I/O file descriptors to the specified file. Since
165	# the daemon has no controlling terminal, most daemons redirect stdin,	165	# the daemon has no controlling terminal, most daemons redirect stdin,
166	# stdout, and stderr to /dev/null. This is done to prevent side-effects	166	# stdout, and stderr to /dev/null. This is done to prevent side-effects
167	# from reads and writes to the standard I/O file descriptors.	167	# from reads and writes to the standard I/O file descriptors.
168		168
169	# This call to open is guaranteed to return the lowest file descriptor,	169	# This call to open is guaranteed to return the lowest file descriptor,
170	# which will be 0 (stdin), since it was closed above.	170	# which will be 0 (stdin), since it was closed above.
171	# os.open(REDIRECT_TO, os.O_RDWR) # standard input (0)	171	# os.open(REDIRECT_TO, os.O_RDWR) # standard input (0)
172		172
173	# Duplicate standard input to standard output and standard error.	173	# Duplicate standard input to standard output and standard error.
174	# os.dup2(0, 1) # standard output (1)	174	# os.dup2(0, 1) # standard output (1)
175	# os.dup2(0, 2) # standard error (2)	175	# os.dup2(0, 2) # standard error (2)
176		176
177		177
178	si = file('/dev/null', 'r')	178	si = file('/dev/null', 'r')
179	so = file(logfile, 'w')	179	so = file(logfile, 'w')
180	se = so	180	se = so
181		181
182		182
183	# Replace those fds with our own	183	# Replace those fds with our own
184	os.dup2(si.fileno(), sys.stdin.fileno())	184	os.dup2(si.fileno(), sys.stdin.fileno())
185	os.dup2(so.fileno(), sys.stdout.fileno())	185	os.dup2(so.fileno(), sys.stdout.fileno())
186	os.dup2(se.fileno(), sys.stderr.fileno())	186	os.dup2(se.fileno(), sys.stderr.fileno())
187		187
188	function()	188	function()
189
190	os._exit(0)
191		189
		190	os._exit(0)