core-extra/daemon/core/misc/utils.py
ahrenholz 454d17a245 (Boeing r1774)
added which() function to search full PATH for executable; use it in checkexec()
2013-09-12 19:07:41 +00:00

245 lines
7.2 KiB
Python

#
# CORE
# Copyright (c)2010-2012 the Boeing Company.
# See the LICENSE file included in this distribution.
#
# authors: Tom Goff <thomas.goff@boeing.com>
# Jeff Ahrenholz <jeffrey.m.ahrenholz@boeing.com>
#
'''
utils.py: miscellaneous utility functions, wrappers around some subprocess
procedures.
'''
import subprocess, os, ast
def checkexec(execlist):
for bin in execlist:
if which(bin) is None:
raise EnvironmentError, "executable not found: %s" % bin
def which(program):
''' From: http://stackoverflow.com/questions/377017/test-if-executable-exists-in-python
'''
def is_exe(fpath):
return os.path.isfile(fpath) and os.access(fpath, os.X_OK)
fpath, fname = os.path.split(program)
if fpath:
if is_exe(program):
return program
else:
for path in os.environ["PATH"].split(os.pathsep):
path = path.strip('"')
exe_file = os.path.join(path, program)
if is_exe(exe_file):
return exe_file
return None
def ensurepath(pathlist):
searchpath = os.environ["PATH"].split(":")
for p in set(pathlist):
if p not in searchpath:
os.environ["PATH"] += ":" + p
def maketuple(obj):
if hasattr(obj, "__iter__"):
return tuple(obj)
else:
return (obj,)
def maketuplefromstr(s, type):
s.replace('\\', '\\\\')
return ast.literal_eval(s)
#return tuple(type(i) for i in s[1:-1].split(','))
#r = ()
#for i in s.strip("()").split(','):
# r += (i.strip("' "), )
# chop empty last element from "('a',)" strings
#if r[-1] == '':
# r = r[:-1]
#return r
def call(*args, **kwds):
return subprocess.call(*args, **kwds)
def mutecall(*args, **kwds):
kwds["stdout"] = open(os.devnull, "w")
kwds["stderr"] = subprocess.STDOUT
return call(*args, **kwds)
def check_call(*args, **kwds):
return subprocess.check_call(*args, **kwds)
def mutecheck_call(*args, **kwds):
kwds["stdout"] = open(os.devnull, "w")
kwds["stderr"] = subprocess.STDOUT
return subprocess.check_call(*args, **kwds)
def spawn(*args, **kwds):
return subprocess.Popen(*args, **kwds).pid
def mutespawn(*args, **kwds):
kwds["stdout"] = open(os.devnull, "w")
kwds["stderr"] = subprocess.STDOUT
return subprocess.Popen(*args, **kwds).pid
def detachinit():
if os.fork():
os._exit(0) # parent exits
os.setsid()
def detach(*args, **kwds):
kwds["preexec_fn"] = detachinit
return subprocess.Popen(*args, **kwds).pid
def mutedetach(*args, **kwds):
kwds["preexec_fn"] = detachinit
kwds["stdout"] = open(os.devnull, "w")
kwds["stderr"] = subprocess.STDOUT
return subprocess.Popen(*args, **kwds).pid
def hexdump(s, bytes_per_word = 2, words_per_line = 8):
dump = ""
count = 0
bytes = bytes_per_word * words_per_line
while s:
line = s[:bytes]
s = s[bytes:]
tmp = map(lambda x: ("%02x" * bytes_per_word) % x,
zip(*[iter(map(ord, line))] * bytes_per_word))
if len(line) % 2:
tmp.append("%x" % ord(line[-1]))
dump += "0x%08x: %s\n" % (count, " ".join(tmp))
count += len(line)
return dump[:-1]
def filemunge(pathname, header, text):
''' Insert text at the end of a file, surrounded by header comments.
'''
filedemunge(pathname, header) # prevent duplicates
f = open(pathname, 'a')
f.write("# BEGIN %s\n" % header)
f.write(text)
f.write("# END %s\n" % header)
f.close()
def filedemunge(pathname, header):
''' Remove text that was inserted in a file surrounded by header comments.
'''
f = open(pathname, 'r')
lines = f.readlines()
f.close()
start = None
end = None
for i in range(len(lines)):
if lines[i] == "# BEGIN %s\n" % header:
start = i
elif lines[i] == "# END %s\n" % header:
end = i + 1
if start is None or end is None:
return
f = open(pathname, 'w')
lines = lines[:start] + lines[end:]
f.write("".join(lines))
f.close()
def expandcorepath(pathname, session=None, node=None):
''' Expand a file path given session information.
'''
if session is not None:
pathname = pathname.replace('~', "/home/%s" % session.user)
pathname = pathname.replace('%SESSION%', str(session.sessionid))
pathname = pathname.replace('%SESSION_DIR%', session.sessiondir)
pathname = pathname.replace('%SESSION_USER%', session.user)
if node is not None:
pathname = pathname.replace('%NODE%', str(node.objid))
pathname = pathname.replace('%NODENAME%', node.name)
return pathname
def sysctldevname(devname):
''' Translate a device name to the name used with sysctl.
'''
if devname is None:
return None
return devname.replace(".", "/")
def daemonize(rootdir = "/", umask = 0, close_fds = False, dontclose = (),
stdin = os.devnull, stdout = os.devnull, stderr = os.devnull,
stdoutmode = 0644, stderrmode = 0644, pidfilename = None,
defaultmaxfd = 1024):
''' Run the background process as a daemon.
'''
if not hasattr(dontclose, "__contains__"):
if not isinstance(dontclose, int):
raise TypeError, "dontclose must be an integer"
dontclose = (int(dontclose),)
else:
for fd in dontclose:
if not isinstance(fd, int):
raise TypeError, "dontclose must contain only integers"
# redirect stdin
if stdin:
fd = os.open(stdin, os.O_RDONLY)
os.dup2(fd, 0)
os.close(fd)
# redirect stdout
if stdout:
fd = os.open(stdout, os.O_WRONLY | os.O_CREAT | os.O_APPEND,
stdoutmode)
os.dup2(fd, 1)
if (stdout == stderr):
os.dup2(1, 2)
os.close(fd)
# redirect stderr
if stderr and (stderr != stdout):
fd = os.open(stderr, os.O_WRONLY | os.O_CREAT | os.O_APPEND,
stderrmode)
os.dup2(fd, 2)
os.close(fd)
if os.fork():
os._exit(0) # parent exits
os.setsid()
pid = os.fork()
if pid:
if pidfilename:
try:
f = open(pidfilename, "w")
f.write("%s\n" % pid)
f.close()
except:
pass
os._exit(0) # parent exits
if rootdir:
os.chdir(rootdir)
os.umask(umask)
if close_fds:
try:
maxfd = resource.getrlimit(resource.RLIMIT_NOFILE)[1]
if maxfd == resource.RLIM_INFINITY:
raise ValueError
except:
maxfd = defaultmaxfd
for fd in xrange(3, maxfd):
if fd in dontclose:
continue
try:
os.close(fd)
except:
pass
def readfileintodict(filename, d):
''' Read key=value pairs from a file, into a dict.
Skip comments; strip newline characters and spacing.
'''
with open(filename, 'r') as f:
lines = f.readlines()
for l in lines:
if l[:1] == '#':
continue
try:
key, value = l.split('=', 1)
d[key] = value.strip()
except ValueError:
pass