xref: /external/chromium_org/build/android/pylib/cmd_helper.py

# Copyright (c) 2012 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""A wrapper for subprocess to make calling shell commands easier."""

import os
import logging
import pipes
import signal
import subprocess
import tempfile

import constants


def Call(args, stdout=None, stderr=None, shell=None, cwd=None, env=None):
  return subprocess.call(
      args=args, cwd=cwd, stdout=stdout, stderr=stderr,
      shell=shell, close_fds=True, env=env,
      preexec_fn=lambda: signal.signal(signal.SIGPIPE, signal.SIG_DFL))


def RunCmd(args, cwd=None):
  """Opens a subprocess to execute a program and returns its return value.

  Args:
    args: A string or a sequence of program arguments. The program to execute is
      the string or the first item in the args sequence.
    cwd: If not None, the subprocess's current directory will be changed to
      |cwd| before it's executed.

  Returns:
    Return code from the command execution.
  """
  logging.info(str(args) + ' ' + (cwd or ''))
  return Call(args, cwd=cwd)


def GetCmdOutput(args, cwd=None, shell=False):
  """Open a subprocess to execute a program and returns its output.

  Args:
    args: A string or a sequence of program arguments. The program to execute is
      the string or the first item in the args sequence.
    cwd: If not None, the subprocess's current directory will be changed to
      |cwd| before it's executed.
    shell: Whether to execute args as a shell command.

  Returns:
    Captures and returns the command's stdout.
    Prints the command's stderr to logger (which defaults to stdout).
  """
  (_, output) = GetCmdStatusAndOutput(args, cwd, shell)
  return output


def GetCmdStatusAndOutput(args, cwd=None, shell=False):
  """Executes a subprocess and returns its exit code and output.

  Args:
    args: A string or a sequence of program arguments. The program to execute is
      the string or the first item in the args sequence.
    cwd: If not None, the subprocess's current directory will be changed to
      |cwd| before it's executed.
    shell: Whether to execute args as a shell command.

  Returns:
    The tuple (exit code, output).
  """
  if isinstance(args, basestring):
    args_repr = args
    if not shell:
      raise Exception('string args must be run with shell=True')
  elif shell:
    raise Exception('array args must be run with shell=False')
  else:
    args_repr = ' '.join(map(pipes.quote, args))

  s = '[host]'
  if cwd:
    s += ':' + cwd
  s += '> ' + args_repr
  logging.info(s)
  tmpout = tempfile.TemporaryFile(bufsize=0)
  tmperr = tempfile.TemporaryFile(bufsize=0)
  exit_code = Call(args, cwd=cwd, stdout=tmpout, stderr=tmperr, shell=shell)
  tmperr.seek(0)
  stderr = tmperr.read()
  tmperr.close()
  if stderr:
    logging.critical(stderr)
  tmpout.seek(0)
  stdout = tmpout.read()
  tmpout.close()
  if len(stdout) > 4096:
    logging.debug('Truncated output:')
  logging.debug(stdout[:4096])
  return (exit_code, stdout)


class OutDirectory(object):
  _out_directory = os.path.join(constants.DIR_SOURCE_ROOT,
      os.environ.get('CHROMIUM_OUT_DIR','out'))
  @staticmethod
  def set(out_directory):
    OutDirectory._out_directory = out_directory
  @staticmethod
  def get():
    return OutDirectory._out_directory