def start(self):
try:
os.fstat(self._savefd)
except OSError:
raise ValueError("saved filedescriptor not valid, "
"did you call start() twice?")
if self.targetfd == 0 and not self.tmpfile:
fd = os.open(devnullpath, os.O_RDONLY)
os.dup2(fd, 0)
os.close(fd)
if hasattr(self, '_oldsys'):
setattr(sys, patchsysdict[self.targetfd], DontReadFromInput())
else:
os.dup2(self.tmpfile.fileno(), self.targetfd)
if hasattr(self, '_oldsys'):
setattr(sys, patchsysdict[self.targetfd], self.tmpfile)
python类dup2()的实例源码
def daemonize():
# See http://www.erlenstar.demon.co.uk/unix/faq_toc.html#TOC16
if os.fork(): # launch child and...
os._exit(0) # kill off parent
os.setsid()
if os.fork(): # launch child and...
os._exit(0) # kill off parent again.
os.umask(077)
null=os.open('/dev/null', os.O_RDWR)
for i in range(3):
try:
os.dup2(null, i)
except OSError, e:
if e.errno != errno.EBADF:
raise
os.close(null)
def __init__(self, cmd, bufsize=-1):
_cleanup()
self.cmd = cmd
p2cread, p2cwrite = os.pipe()
c2pread, c2pwrite = os.pipe()
self.pid = os.fork()
if self.pid == 0:
# Child
os.dup2(p2cread, 0)
os.dup2(c2pwrite, 1)
os.dup2(c2pwrite, 2)
self._run_child(cmd)
os.close(p2cread)
self.tochild = os.fdopen(p2cwrite, 'w', bufsize)
os.close(c2pwrite)
self.fromchild = os.fdopen(c2pread, 'r', bufsize)
def __init__(self, stream, filename):
self._stream = stream
self._fd = stream.fileno()
self._filename = filename
# Keep original stream for later
self._uncaptured_fd = os.dup(self._fd)
# Open file to save stream to
cap_fd = os.open(self._filename,
os.O_CREAT | os.O_TRUNC | os.O_WRONLY,
0600)
# Send stream to this file
self._stream.flush()
os.dup2(cap_fd, self._fd)
os.close(cap_fd)
def __init__(self, stream, filename):
self._stream = stream
self._fd = stream.fileno()
self._filename = filename
# Keep original stream for later
self._uncaptured_fd = os.dup(self._fd)
# Open file to save stream to
cap_fd = os.open(self._filename,
os.O_CREAT | os.O_TRUNC | os.O_WRONLY,
0600)
# Send stream to this file
self._stream.flush()
os.dup2(cap_fd, self._fd)
os.close(cap_fd)
def daemonize(self):
try:
pid = os.fork()
if pid > 0:
sys.exit(0)
except OSError, e:
sys.stderr.write("fork #1 failed: %d (%s)\n" % (e.errno, e.strerror))
sys.exit(1)
os.chdir("/")
os.setsid()
os.umask(0)
try:
pid = os.fork()
if pid > 0:
sys.exit(0)
except OSError, e:
sys.stderr.write("fork #2 failed: %d (%s)\n" % (e.errno, e.strerror))
sys.exit(1)
sys.stdout.flush()
sys.stderr.flush()
si = file(self.stdin, 'r')
so = file(self.stdout, 'a+')
se = file(self.stderr, 'a+', 0)
os.dup2(si.fileno(), sys.stdin.fileno())
os.dup2(so.fileno(), sys.stdout.fileno())
os.dup2(se.fileno(), sys.stderr.fileno())
atexit.register(self.delpid)
pid = str(os.getpid())
file(self.pidfile,'w+').write("%s\n" % pid)
def daemonize(double_fork=True):
'''Puts process in the background using usual UNIX best practices.'''
try:
os.umask(0o22)
except Exception as e:
raise Exception("Unable to change file creation mask: %s" % e)
os.chdir('/')
# First fork
if double_fork:
try:
pid = os.fork()
if pid > 0:
os._exit(0)
except OSError as e:
raise Exception("Error on first fork: [%d] %s" % (e.errno, e.strerr,))
os.setsid()
# Second fork
try:
pid = os.fork()
if pid > 0:
os._exit(0)
except OSError as e:
raise Exception("Error on second fork: [%d] %s" % (e.errno, e.strerr,))
close_open_files()
os.dup2(os.open(os.devnull, os.O_RDWR), sys.stdin.fileno())
os.dup2(os.open(os.devnull, os.O_RDWR), sys.stdout.fileno())
os.dup2(os.open(os.devnull, os.O_RDWR), sys.stderr.fileno())
def start(self):
""" Setup the redirection.
"""
if not self.started:
self.oldhandle = os.dup(self.fd)
self.piper, self.pipew = os.pipe()
os.dup2(self.pipew, self.fd)
os.close(self.pipew)
self.started = True
def stop(self):
""" Unset the redirection and return the captured output.
"""
if self.started:
self.flush()
os.dup2(self.oldhandle, self.fd)
os.close(self.oldhandle)
f = os.fdopen(self.piper, 'r')
output = f.read()
f.close()
self.started = False
return output
else:
return ''
def start(self):
""" Setup the redirection.
"""
if not self.started:
self.oldhandle = os.dup(self.fd)
self.piper, self.pipew = os.pipe()
os.dup2(self.pipew, self.fd)
os.close(self.pipew)
self.started = True
def stop(self):
""" Unset the redirection and return the captured output.
"""
if self.started:
self.flush()
os.dup2(self.oldhandle, self.fd)
os.close(self.oldhandle)
f = os.fdopen(self.piper, 'r')
output = f.read()
f.close()
self.started = False
return output
else:
return ''
def __init__(self, cmd, capturestderr=False, bufsize=-1):
"""The parameter 'cmd' is the shell command to execute in a
sub-process. On UNIX, 'cmd' may be a sequence, in which case arguments
will be passed directly to the program without shell intervention (as
with os.spawnv()). If 'cmd' is a string it will be passed to the shell
(as with os.system()). The 'capturestderr' flag, if true, specifies
that the object should capture standard error output of the child
process. The default is false. If the 'bufsize' parameter is
specified, it specifies the size of the I/O buffers to/from the child
process."""
_cleanup()
self.cmd = cmd
p2cread, p2cwrite = os.pipe()
c2pread, c2pwrite = os.pipe()
if capturestderr:
errout, errin = os.pipe()
self.pid = os.fork()
if self.pid == 0:
# Child
os.dup2(p2cread, 0)
os.dup2(c2pwrite, 1)
if capturestderr:
os.dup2(errin, 2)
self._run_child(cmd)
os.close(p2cread)
self.tochild = os.fdopen(p2cwrite, 'w', bufsize)
os.close(c2pwrite)
self.fromchild = os.fdopen(c2pread, 'r', bufsize)
if capturestderr:
os.close(errin)
self.childerr = os.fdopen(errout, 'r', bufsize)
else:
self.childerr = None
def freopen(f, mode, stream):
oldf = open(f, mode)
oldfd = oldf.fileno()
newfd = stream.fileno()
os.close(newfd)
os.dup2(oldfd, newfd)
def daemonize(stdin="/dev/null", stdout="/dev/null", stderr="/dev/null"):
'''
Daemonize current script
'''
try:
pid = os.fork()
if pid > 0:
sys.exit(0)
except OSError, e:
sys.stderr.write ("fork #1 failed: (%d) %s\n" % (e.errno, e.strerror) )
sys.exit(1)
os.chdir("/")
os.umask(0)
os.setsid()
try:
pid = os.fork()
if pid > 0:
sys.exit(0)
except OSError, e:
sys.stderr.write ("fork #2 failed: (%d) %s\n" % (e.errno, e.strerror) )
sys.exit(1)
stdin_par = os.path.dirname(stdin)
stdout_par = os.path.dirname(stdout)
stderr_par = os.path.dirname(stderr)
if not stdin_par:
os.path.makedirs(stdin_par)
if not stdout_par:
os.path.makedirs(stdout_par)
if not stderr_par:
os.path.makedirs(stderr_par)
si = open(stdin, 'r')
so = open(stdout, 'a+')
se = open(stderr, 'a+', 0)
os.dup2(si.fileno(), sys.stdin.fileno())
os.dup2(so.fileno(), sys.stdout.fileno())
os.dup2(se.fileno(), sys.stderr.fileno())
def cli(ctx, index):
# Get settings from CustomScriptForLinux extension configurations
waagent.LoggerInit('/var/log/waagent.log', '/dev/null')
ctx.meta["settings"] = settings = get_settings()
ctx.meta["index-file"] = index
group = ctx.command
commands = sorted([c for c in group.commands])
# start logging to stdout and install.log
sys.stdout = os.fdopen(sys.stdout.fileno(), 'w', 0)
username = settings["username"]
log_file = os.path.join("/home", username, "pcf_install.log")
tee = Popen(["tee", log_file], stdin=PIPE)
os.dup2(tee.stdin.fileno(), sys.stdout.fileno())
os.dup2(tee.stdin.fileno(), sys.stderr.fileno())
if ctx.invoked_subcommand is None:
for command in commands:
command = re.sub('\d{2}_', '', command)
print "Running {0}...".format(command)
ctx.invoke(eval(command))
else:
pass
def redirect(self):
sys.stdout.flush()
sys.stderr.flush()
os.dup2(self.input.fileno(), sys.stdin.fileno())
os.dup2(self.output.fileno(), sys.stdout.fileno())
os.dup2(self.output.fileno(), sys.stderr.fileno())
def redirect(self):
sys.stdout.flush()
sys.stderr.flush()
os.dup2(self.input.fileno(), sys.stdin.fileno())
os.dup2(self.output.fileno(), sys.stdout.fileno())
os.dup2(self.output.fileno(), sys.stderr.fileno())
def redirect(self):
sys.stdout.flush()
sys.stderr.flush()
os.dup2(self.input.fileno(), sys.stdin.fileno())
os.dup2(self.output.fileno(), sys.stdout.fileno())
os.dup2(self.output.fileno(), sys.stderr.fileno())
def redirect(self):
sys.stdout.flush()
sys.stderr.flush()
os.dup2(self.stdin.fileno(), sys.stdin.fileno())
os.dup2(self.stdout.fileno(), sys.stdout.fileno())
os.dup2(self.stderr.fileno(), sys.stderr.fileno())
# private only
def redirect(self):
sys.stdout.flush()
sys.stderr.flush()
os.dup2(self.input.fileno(), sys.stdin.fileno())
os.dup2(self.output.fileno(), sys.stdout.fileno())
os.dup2(self.output.fileno(), sys.stderr.fileno())
