def git(self, cmd, extra_args=(), capture_stdout=False,
capture_stderr=False, check=True, cwd=None):
'''Helper for running a git command using metadata from a Project
instance.
:param cmd: git command as a string (or list of strings); all strings
are formatted using self.format() before use.
:param extra_args: sequence of additional arguments to pass to the git
command (useful mostly if cmd is a string).
:param capture_stdout: True if stdout should be captured into the
returned object instead of being printed.
:param capture_stderr: Like capture_stdout, but for stderr. Use with
caution as it prevents error messages from being
shown to the user.
:param check: True if a subprocess.CalledProcessError should be raised
if the git command finishes with a non-zero return code.
:param cwd: directory to run command in (default: self.abspath)
Returns a CompletedProcess (which is back-ported for Python 3.4).'''
_warn_once_if_no_git()
if isinstance(cmd, str):
cmd_list = shlex.split(cmd)
else:
cmd_list = list(cmd)
extra_args = list(extra_args)
if cwd is None:
cwd = self.abspath
args = ['git'] + [self.format(arg) for arg in cmd_list] + extra_args
cmd_str = util.quote_sh_list(args)
log.dbg("running '{}'".format(cmd_str), 'in', cwd,
level=log.VERBOSE_VERY)
popen = subprocess.Popen(
args, cwd=cwd,
stdout=subprocess.PIPE if capture_stdout else None,
stderr=subprocess.PIPE if capture_stderr else None)
stdout, stderr = popen.communicate()
dbg_msg = "'{}' in {} finished with exit status {}".format(
cmd_str, cwd, popen.returncode)
if capture_stdout:
dbg_msg += " and wrote {} to stdout".format(stdout)
if capture_stderr:
dbg_msg += " and wrote {} to stderr".format(stderr)
log.dbg(dbg_msg, level=log.VERBOSE_VERY)
if check and popen.returncode:
raise subprocess.CalledProcessError(popen.returncode, cmd_list,
output=stdout, stderr=stderr)
else:
return CompletedProcess(popen.args, popen.returncode,
stdout, stderr)