import logging import signal import subprocess logger = logging.getLogger('BitBake.Process') def subprocess_setup(): # Python installs a SIGPIPE handler by default. This is usually not what # non-Python subprocesses expect. signal.signal(signal.SIGPIPE, signal.SIG_DFL) class CmdError(RuntimeError): def __init__(self, command, message=None): self.command = command self.message = message def __str__(self): if not isinstance(self.command, basestring): cmd = subprocess.list2cmdline(self.command) else: cmd = self.command msg = "Execution of '%s' failed" % cmd if self.message: msg += ': %s' % self.message return msg class NotFoundError(CmdError): def __str__(self): return CmdError.__str__(self) + ": command not found" class ExecutionError(CmdError): def __init__(self, command, exitcode, stdout = None, stderr = None): CmdError.__init__(self, command) self.exitcode = exitcode self.stdout = stdout self.stderr = stderr def __str__(self): message = "" if self.stderr: message += self.stderr if self.stdout: message += self.stdout if message: message = ":\n" + message return (CmdError.__str__(self) + " with exit code %s" % self.exitcode + message) class Popen(subprocess.Popen): defaults = { "close_fds": True, "preexec_fn": subprocess_setup, "stdout": subprocess.PIPE, "stderr": subprocess.STDOUT, "stdin": subprocess.PIPE, "shell": False, } def __init__(self, *args, **kwargs): options = dict(self.defaults) options.update(kwargs) subprocess.Popen.__init__(self, *args, **options) def _logged_communicate(pipe, log, input): if pipe.stdin: if input is not None: pipe.stdin.write(input) pipe.stdin.close() bufsize = 512 outdata, errdata = [], [] while pipe.poll() is None: if pipe.stdout is not None: data = pipe.stdout.read(bufsize) if data is not None: outdata.append(data) log.write(data) if pipe.stderr is not None: data = pipe.stderr.read(bufsize) if data is not None: errdata.append(data) log.write(data) return ''.join(outdata), ''.join(errdata) def run(cmd, input=None, **options): """Convenience function to run a command and return its output, raising an exception when the command fails""" if isinstance(cmd, basestring) and not "shell" in options: options["shell"] = True log = options.get('log') if 'log' in options: del options['log'] try: pipe = Popen(cmd, **options) except OSError, exc: if exc.errno == 2: raise NotFoundError(cmd) else: raise CmdError(cmd, exc) if log: stdout, stderr = _logged_communicate(pipe, log, input) else: stdout, stderr = pipe.communicate(input) if pipe.returncode != 0: raise ExecutionError(cmd, pipe.returncode, stdout, stderr) return stdout, stderr