def cleanup():
while spawned_pids:
pid = spawned_pids.pop()
try:
# With waitpid and WNOHANG, only check the
# first element of the tuple since the second
# element may vary (bug #337465).
if os.waitpid(pid, os.WNOHANG)[0] == 0:
os.kill(pid, signal.SIGTERM)
os.waitpid(pid, 0)
except OSError:
# This pid has been cleaned up outside
# of spawn().
pass
def cleanup():
while spawned_pids:
pid = spawned_pids.pop()
try:
# With waitpid and WNOHANG, only check the
# first element of the tuple since the second
# element may vary (bug #337465).
if os.waitpid(pid, os.WNOHANG)[0] == 0:
os.kill(pid, signal.SIGTERM)
os.waitpid(pid, 0)
except OSError:
# This pid has been cleaned up outside
# of spawn().
pass
def spawn(mycommand,
env={},
opt_name=None,
fd_pipes=None,
returnpid=False,
uid=None,
gid=None,
groups=None,
umask=None,
logfile=None,
path_lookup=True,
pre_exec=None):
"""
Spawns a given command.
@param mycommand: the command to execute
@type mycommand: String or List (Popen style list)
@param env: A dict of Key=Value pairs for env variables
@type env: Dictionary
@param opt_name: an optional name for the spawn'd process (defaults to the binary name)
@type opt_name: String
@param fd_pipes: A dict of mapping for pipes, { '0': stdin, '1': stdout } for example
@type fd_pipes: Dictionary
@param returnpid: Return the Process IDs for a successful spawn.
NOTE: This requires the caller clean up all the PIDs, otherwise spawn will clean them.
@type returnpid: Boolean
@param uid: User ID to spawn as; useful for dropping privilages
@type uid: Integer
@param gid: Group ID to spawn as; useful for dropping privilages
@type gid: Integer
@param groups: Group ID's to spawn in: useful for having the process run in multiple group contexts.
@type groups: List
@param umask: An integer representing the umask for the process (see man chmod for umask details)
@type umask: Integer
@param logfile: name of a file to use for logging purposes
@type logfile: String
@param path_lookup: If the binary is not fully specified then look for it in PATH
@type path_lookup: Boolean
@param pre_exec: A function to be called with no arguments just prior to the exec call.
@type pre_exec: callable
logfile requires stdout and stderr to be assigned to this process (ie not pointed
somewhere else.)
"""
# mycommand is either a str or a list
if isinstance(mycommand, basestring):
mycommand = mycommand.split()
if sys.hexversion < 0x3000000:
# Avoid a potential UnicodeEncodeError from os.execve().
env_bytes = {}
for k, v in env.items():
env_bytes[_unicode_encode(k, encoding=_encodings['content'])] = \
_unicode_encode(v, encoding=_encodings['content'])
env = env_bytes
del env_bytes
# If an absolute path to an executable file isn't given
# search for it unless we've been told not to.
binary = mycommand[0]
if binary not in (BASH_BINARY, SANDBOX_BINARY, FAKEROOT_BINARY) and \
(not os.path.isabs(binary) or not os.path.isfile(binary)
or not os.access(binary, os.X_OK)):
binary = path_lookup and find_binary(binary) or None
if not binary:
raise CommandNotFound(mycommand[0])
# If we haven't been told what file descriptors to use
# default to propagating our stdin, stdout and stderr.
if fd_pipes is None:
fd_pipes = {
0: sys.stdin.fileno(),
1: sys.stdout.fileno(),
2: sys.stderr.fileno(),
}
# mypids will hold the pids of all processes created.
mypids = []
if logfile:
# Using a log file requires that stdout and stderr
# are assigned to the process we're running.
if 1 not in fd_pipes or 2 not in fd_pipes:
raise ValueError(fd_pipes)
# Create a pipe
(pr, pw) = os.pipe()
# Create a tee process, giving it our stdout and stderr
# as well as the read end of the pipe.
mypids.extend(
spawn(('tee', '-i', '-a', logfile),
returnpid=True,
fd_pipes={
0: pr,
1: fd_pipes[1],
2: fd_pipes[2]
}))
# We don't need the read end of the pipe, so close it.
os.close(pr)
# Assign the write end of the pipe to our stdout and stderr.
fd_pipes[1] = pw
fd_pipes[2] = pw
pid = os.fork()
if pid == 0:
try:
_exec(binary, mycommand, opt_name, fd_pipes, env, gid, groups, uid,
umask, pre_exec)
except SystemExit:
raise
except Exception as e:
# We need to catch _any_ exception so that it doesn't
# propagate out of this function and cause exiting
# with anything other than os._exit()
sys.stderr.write("%s:\n %s\n" % (e, " ".join(mycommand)))
traceback.print_exc()
sys.stderr.flush()
os._exit(1)
if not isinstance(pid, int):
raise AssertionError("fork returned non-integer: %s" % (repr(pid), ))
# Add the pid to our local and the global pid lists.
mypids.append(pid)
spawned_pids.append(pid)
# If we started a tee process the write side of the pipe is no
# longer needed, so close it.
if logfile:
os.close(pw)
# If the caller wants to handle cleaning up the processes, we tell
# it about all processes that were created.
if returnpid:
return mypids
# Otherwise we clean them up.
while mypids:
# Pull the last reader in the pipe chain. If all processes
# in the pipe are well behaved, it will die when the process
# it is reading from dies.
pid = mypids.pop(0)
# and wait for it.
retval = os.waitpid(pid, 0)[1]
# When it's done, we can remove it from the
# global pid list as well.
spawned_pids.remove(pid)
if retval:
# If it failed, kill off anything else that
# isn't dead yet.
for pid in mypids:
# With waitpid and WNOHANG, only check the
# first element of the tuple since the second
# element may vary (bug #337465).
if os.waitpid(pid, os.WNOHANG)[0] == 0:
os.kill(pid, signal.SIGTERM)
os.waitpid(pid, 0)
spawned_pids.remove(pid)
# If it got a signal, return the signal that was sent.
if (retval & 0xff):
return ((retval & 0xff) << 8)
# Otherwise, return its exit code.
return (retval >> 8)
# Everything succeeded
return 0
def spawn(mycommand, env={}, opt_name=None, fd_pipes=None, returnpid=False,
uid=None, gid=None, groups=None, umask=None, logfile=None,
path_lookup=True, pre_exec=None):
"""
Spawns a given command.
@param mycommand: the command to execute
@type mycommand: String or List (Popen style list)
@param env: A dict of Key=Value pairs for env variables
@type env: Dictionary
@param opt_name: an optional name for the spawn'd process (defaults to the binary name)
@type opt_name: String
@param fd_pipes: A dict of mapping for pipes, { '0': stdin, '1': stdout } for example
@type fd_pipes: Dictionary
@param returnpid: Return the Process IDs for a successful spawn.
NOTE: This requires the caller clean up all the PIDs, otherwise spawn will clean them.
@type returnpid: Boolean
@param uid: User ID to spawn as; useful for dropping privilages
@type uid: Integer
@param gid: Group ID to spawn as; useful for dropping privilages
@type gid: Integer
@param groups: Group ID's to spawn in: useful for having the process run in multiple group contexts.
@type groups: List
@param umask: An integer representing the umask for the process (see man chmod for umask details)
@type umask: Integer
@param logfile: name of a file to use for logging purposes
@type logfile: String
@param path_lookup: If the binary is not fully specified then look for it in PATH
@type path_lookup: Boolean
@param pre_exec: A function to be called with no arguments just prior to the exec call.
@type pre_exec: callable
logfile requires stdout and stderr to be assigned to this process (ie not pointed
somewhere else.)
"""
# mycommand is either a str or a list
if isinstance(mycommand, basestring):
mycommand = mycommand.split()
if sys.hexversion < 0x3000000:
# Avoid a potential UnicodeEncodeError from os.execve().
env_bytes = {}
for k, v in env.items():
env_bytes[_unicode_encode(k, encoding=_encodings['content'])] = \
_unicode_encode(v, encoding=_encodings['content'])
env = env_bytes
del env_bytes
# If an absolute path to an executable file isn't given
# search for it unless we've been told not to.
binary = mycommand[0]
if binary not in (BASH_BINARY, SANDBOX_BINARY, FAKEROOT_BINARY) and \
(not os.path.isabs(binary) or not os.path.isfile(binary)
or not os.access(binary, os.X_OK)):
binary = path_lookup and find_binary(binary) or None
if not binary:
raise CommandNotFound(mycommand[0])
# If we haven't been told what file descriptors to use
# default to propagating our stdin, stdout and stderr.
if fd_pipes is None:
fd_pipes = {
0:sys.stdin.fileno(),
1:sys.stdout.fileno(),
2:sys.stderr.fileno(),
}
# mypids will hold the pids of all processes created.
mypids = []
if logfile:
# Using a log file requires that stdout and stderr
# are assigned to the process we're running.
if 1 not in fd_pipes or 2 not in fd_pipes:
raise ValueError(fd_pipes)
# Create a pipe
(pr, pw) = os.pipe()
# Create a tee process, giving it our stdout and stderr
# as well as the read end of the pipe.
mypids.extend(spawn(('tee', '-i', '-a', logfile),
returnpid=True, fd_pipes={0:pr,
1:fd_pipes[1], 2:fd_pipes[2]}))
# We don't need the read end of the pipe, so close it.
os.close(pr)
# Assign the write end of the pipe to our stdout and stderr.
fd_pipes[1] = pw
fd_pipes[2] = pw
pid = os.fork()
if pid == 0:
try:
_exec(binary, mycommand, opt_name, fd_pipes,
env, gid, groups, uid, umask, pre_exec)
except SystemExit:
raise
except Exception as e:
# We need to catch _any_ exception so that it doesn't
# propagate out of this function and cause exiting
# with anything other than os._exit()
sys.stderr.write("%s:\n %s\n" % (e, " ".join(mycommand)))
traceback.print_exc()
sys.stderr.flush()
os._exit(1)
if not isinstance(pid, int):
raise AssertionError("fork returned non-integer: %s" % (repr(pid),))
# Add the pid to our local and the global pid lists.
mypids.append(pid)
spawned_pids.append(pid)
# If we started a tee process the write side of the pipe is no
# longer needed, so close it.
if logfile:
os.close(pw)
# If the caller wants to handle cleaning up the processes, we tell
# it about all processes that were created.
if returnpid:
return mypids
# Otherwise we clean them up.
while mypids:
# Pull the last reader in the pipe chain. If all processes
# in the pipe are well behaved, it will die when the process
# it is reading from dies.
pid = mypids.pop(0)
# and wait for it.
retval = os.waitpid(pid, 0)[1]
# When it's done, we can remove it from the
# global pid list as well.
spawned_pids.remove(pid)
if retval:
# If it failed, kill off anything else that
# isn't dead yet.
for pid in mypids:
# With waitpid and WNOHANG, only check the
# first element of the tuple since the second
# element may vary (bug #337465).
if os.waitpid(pid, os.WNOHANG)[0] == 0:
os.kill(pid, signal.SIGTERM)
os.waitpid(pid, 0)
spawned_pids.remove(pid)
# If it got a signal, return the signal that was sent.
if (retval & 0xff):
return ((retval & 0xff) << 8)
# Otherwise, return its exit code.
return (retval >> 8)
# Everything succeeded
return 0
