def _exec_command_posix( command,
                         use_shell = None,
                         use_tee = None,
                         **env ):
    log.debug('_exec_command_posix(...)')

    if is_sequence(command):
        command_str = ' '.join(list(command))
    else:
        command_str = command

    tmpfile = temp_file_name()
    stsfile = None
    if use_tee:
        stsfile = temp_file_name()
        filter = ''
        if use_tee == 2:
            filter = r'| tr -cd "\n" | tr "\n" "."; echo'
        command_posix = '( %s ; echo $? > %s ) 2>&1 | tee %s %s'\
                      % (command_str, stsfile, tmpfile, filter)
    else:
        stsfile = temp_file_name()
        command_posix = '( %s ; echo $? > %s ) > %s 2>&1'\
                        % (command_str, stsfile, tmpfile)
        #command_posix = '( %s ) > %s 2>&1' % (command_str,tmpfile)

    log.debug('Running os.system(%r)' % (command_posix))
    status = os.system(command_posix)

    if use_tee:
        if status:
            # if command_tee fails then fall back to robust exec_command
            log.warn('_exec_command_posix failed (status=%s)' % status)
            return _exec_command(command, use_shell=use_shell, **env)

    if stsfile is not None:
        f = open_latin1(stsfile, 'r')
        status_text = f.read()
        status = int(status_text)
        f.close()
        os.remove(stsfile)

    f = open_latin1(tmpfile, 'r')
    text = f.read()
    f.close()
    os.remove(tmpfile)

    if text[-1:]=='\n':
        text = text[:-1]

    return status, text

def _exec_command_python(command,
                         exec_command_dir='', **env):
    log.debug('_exec_command_python(...)')

    python_exe = get_pythonexe()
    cmdfile = temp_file_name()
    stsfile = temp_file_name()
    outfile = temp_file_name()

    f = open(cmdfile, 'w')
    f.write('import os\n')
    f.write('import sys\n')
    f.write('sys.path.insert(0,%r)\n' % (exec_command_dir))
    f.write('from exec_command import exec_command\n')
    f.write('del sys.path[0]\n')
    f.write('cmd = %r\n' % command)
    f.write('os.environ = %r\n' % (os.environ))
    f.write('s,o = exec_command(cmd, _with_python=0, **%r)\n' % (env))
    f.write('f=open(%r,"w")\nf.write(str(s))\nf.close()\n' % (stsfile))
    f.write('f=open(%r,"w")\nf.write(o)\nf.close()\n' % (outfile))
    f.close()

    cmd = '%s %s' % (python_exe, cmdfile)
    status = os.system(cmd)
    if status:
        raise RuntimeError("%r failed" % (cmd,))
    os.remove(cmdfile)

    f = open_latin1(stsfile, 'r')
    status = int(f.read())
    f.close()
    os.remove(stsfile)

    f = open_latin1(outfile, 'r')
    text = f.read()
    f.close()
    os.remove(outfile)

    return status, text

def get_f77flags(src):
    """
    Search the first 20 lines of fortran 77 code for line pattern
      `CF77FLAGS(<fcompiler type>)=<f77 flags>`
    Return a dictionary {<fcompiler type>:<f77 flags>}.
    """
    flags = {}
    f = open_latin1(src, 'r')
    i = 0
    for line in f:
        i += 1
        if i>20: break
        m = _f77flags_re.match(line)
        if not m: continue
        fcname = m.group('fcname').strip()
        fflags = m.group('fflags').strip()
        flags[fcname] = split_quoted(fflags)
    f.close()
    return flags

def is_free_format(file):
    """Check if file is in free format Fortran."""
    # f90 allows both fixed and free format, assuming fixed unless
    # signs of free format are detected.
    result = 0
    f = open_latin1(file, 'r')
    line = f.readline()
    n = 10000 # the number of non-comment lines to scan for hints
    if _has_f_header(line):
        n = 0
    elif _has_f90_header(line):
        n = 0
        result = 1
    while n>0 and line:
        line = line.rstrip()
        if line and line[0]!='!':
            n -= 1
            if (line[0]!='\t' and _free_f90_start(line[:5])) or line[-1:]=='&':
                result = 1
                break
        line = f.readline()
    f.close()
    return result

def _exec_command( command, use_shell=None, use_tee = None, **env ):
    log.debug('_exec_command(...)')

    if use_shell is None:
        use_shell = os.name=='posix'
    if use_tee is None:
        use_tee = os.name=='posix'
    using_command = 0
    if use_shell:
        # We use shell (unless use_shell==0) so that wildcards can be
        # used.
        sh = os.environ.get('SHELL', '/bin/sh')
        if is_sequence(command):
            argv = [sh, '-c', ' '.join(list(command))]
        else:
            argv = [sh, '-c', command]
    else:
        # On NT, DOS we avoid using command.com as it's exit status is
        # not related to the exit status of a command.
        if is_sequence(command):
            argv = command[:]
        else:
            argv = shlex.split(command)

    if hasattr(os, 'spawnvpe'):
        spawn_command = os.spawnvpe
    else:
        spawn_command = os.spawnve
        argv[0] = find_executable(argv[0]) or argv[0]
        if not os.path.isfile(argv[0]):
            log.warn('Executable %s does not exist' % (argv[0]))
            if os.name in ['nt', 'dos']:
                # argv[0] might be internal command
                argv = [os.environ['COMSPEC'], '/C'] + argv
                using_command = 1

    _so_has_fileno = _supports_fileno(sys.stdout)
    _se_has_fileno = _supports_fileno(sys.stderr)
    so_flush = sys.stdout.flush
    se_flush = sys.stderr.flush
    if _so_has_fileno:
        so_fileno = sys.stdout.fileno()
        so_dup = os.dup(so_fileno)
    if _se_has_fileno:
        se_fileno = sys.stderr.fileno()
        se_dup = os.dup(se_fileno)

    outfile = temp_file_name()
    fout = open(outfile, 'w')
    if using_command:
        errfile = temp_file_name()
        ferr = open(errfile, 'w')

    log.debug('Running %s(%s,%r,%r,os.environ)' \
              % (spawn_command.__name__, os.P_WAIT, argv[0], argv))

    argv0 = argv[0]
    if not using_command:
        argv[0] = quote_arg(argv0)

    so_flush()
    se_flush()
    if _so_has_fileno:
        os.dup2(fout.fileno(), so_fileno)

    if _se_has_fileno:
        if using_command:
            #XXX: disabled for now as it does not work from cmd under win32.
            #     Tests fail on msys
            os.dup2(ferr.fileno(), se_fileno)
        else:
            os.dup2(fout.fileno(), se_fileno)
    try:
        status = spawn_command(os.P_WAIT, argv0, argv, os.environ)
    except OSError:
        errmess = str(get_exception())
        status = 999
        sys.stderr.write('%s: %s'%(errmess, argv[0]))

    so_flush()
    se_flush()
    if _so_has_fileno:
        os.dup2(so_dup, so_fileno)
    if _se_has_fileno:
        os.dup2(se_dup, se_fileno)

    fout.close()
    fout = open_latin1(outfile, 'r')
    text = fout.read()
    fout.close()
    os.remove(outfile)

    if using_command:
        ferr.close()
        ferr = open_latin1(errfile, 'r')
        errmess = ferr.read()
        ferr.close()
        os.remove(errfile)
        if errmess and not status:
            # Not sure how to handle the case where errmess
#.........这里部分代码省略.........

def has_f90_header(src):
    f = open_latin1(src, 'r')
    line = f.readline()
    f.close()
    return _has_f90_header(line) or _has_fix_header(line)

#.........这里部分代码省略.........
    so_flush = sys.stdout.flush
    se_flush = sys.stderr.flush
    if _so_has_fileno:
        so_fileno = sys.stdout.fileno()
        so_dup = os.dup(so_fileno)
    if _se_has_fileno:
        se_fileno = sys.stderr.fileno()
        se_dup = os.dup(se_fileno)

    outfile = temp_file_name()
    fout = open(outfile, 'w')
    if using_command:
        errfile = temp_file_name()
        ferr = open(errfile, 'w')

    log.debug('Running %s(%s,%r,%r,os.environ)' \
              % (spawn_command.__name__, os.P_WAIT, argv[0], argv))

    if sys.version_info[0] >= 3 and os.name == 'nt':
        # Pre-encode os.environ, discarding un-encodable entries,
        # to avoid it failing during encoding as part of spawn. Failure
        # is possible if the environment contains entries that are not
        # encoded using the system codepage as windows expects.
        #
        # This is not necessary on unix, where os.environ is encoded
        # using the surrogateescape error handler and decoded using
        # it as part of spawn.
        encoded_environ = {}
        for k, v in os.environ.items():
            try:
                encoded_environ[k.encode(sys.getfilesystemencoding())] = v.encode(
                    sys.getfilesystemencoding())
            except UnicodeEncodeError:
                log.debug("ignoring un-encodable env entry %s", k)
    else:
        encoded_environ = os.environ

    argv0 = argv[0]
    if not using_command:
        argv[0] = quote_arg(argv0)

    so_flush()
    se_flush()
    if _so_has_fileno:
        os.dup2(fout.fileno(), so_fileno)

    if _se_has_fileno:
        if using_command:
            #XXX: disabled for now as it does not work from cmd under win32.
            #     Tests fail on msys
            os.dup2(ferr.fileno(), se_fileno)
        else:
            os.dup2(fout.fileno(), se_fileno)
    try:
        status = spawn_command(os.P_WAIT, argv0, argv, encoded_environ)
    except Exception:
        errmess = str(get_exception())
        status = 999
        sys.stderr.write('%s: %s'%(errmess, argv[0]))

    so_flush()
    se_flush()
    if _so_has_fileno:
        os.dup2(so_dup, so_fileno)
        os.close(so_dup)
    if _se_has_fileno:
        os.dup2(se_dup, se_fileno)
        os.close(se_dup)

    fout.close()
    fout = open_latin1(outfile, 'r')
    text = fout.read()
    fout.close()
    os.remove(outfile)

    if using_command:
        ferr.close()
        ferr = open_latin1(errfile, 'r')
        errmess = ferr.read()
        ferr.close()
        os.remove(errfile)
        if errmess and not status:
            # Not sure how to handle the case where errmess
            # contains only warning messages and that should
            # not be treated as errors.
            #status = 998
            if text:
                text = text + '\n'
            #text = '%sCOMMAND %r FAILED: %s' %(text,command,errmess)
            text = text + errmess
            print (errmess)
    if text[-1:]=='\n':
        text = text[:-1]
    if status is None:
        status = 0

    if use_tee:
        print (text)

    return status, text

#.........这里部分代码省略.........
    if _so_has_fileno:
        so_fileno = sys.stdout.fileno()
        so_dup = os.dup(so_fileno)
    if _se_has_fileno:
        se_fileno = sys.stderr.fileno()
        se_dup = os.dup(se_fileno)

    outfile = temp_file_name()
    fout = open(outfile, "w")
    if using_command:
        errfile = temp_file_name()
        ferr = open(errfile, "w")

    log.debug("Running %s(%s,%r,%r,os.environ)" % (spawn_command.__name__, os.P_WAIT, argv[0], argv))

    if env and sys.version_info[0] >= 3 and os.name == "nt":
        # Pre-encode os.environ, discarding un-encodable entries,
        # to avoid it failing during encoding as part of spawn. Failure
        # is possible if the environment contains entries that are not
        # encoded using the system codepage as windows expects.
        #
        # This is not necessary on unix, where os.environ is encoded
        # using the surrogateescape error handler and decoded using
        # it as part of spawn.
        encoded_environ = {}
        for k, v in os.environ.items():
            try:
                encoded_environ[k.encode(sys.getfilesystemencoding())] = v.encode(sys.getfilesystemencoding())
            except UnicodeEncodeError:
                log.debug("ignoring un-encodable env entry %s", k)
    else:
        encoded_environ = os.environ

    argv0 = argv[0]
    if not using_command:
        argv[0] = quote_arg(argv0)

    so_flush()
    se_flush()
    if _so_has_fileno:
        os.dup2(fout.fileno(), so_fileno)

    if _se_has_fileno:
        if using_command:
            # XXX: disabled for now as it does not work from cmd under win32.
            #     Tests fail on msys
            os.dup2(ferr.fileno(), se_fileno)
        else:
            os.dup2(fout.fileno(), se_fileno)
    try:
        # Use spawnv in favor of spawnve, unless necessary
        if env:
            status = spawn_command(os.P_WAIT, argv0, argv, encoded_environ)
        else:
            status = spawn_command(os.P_WAIT, argv0, argv)
    except Exception:
        errmess = str(get_exception())
        status = 999
        sys.stderr.write("%s: %s" % (errmess, argv[0]))

    so_flush()
    se_flush()
    if _so_has_fileno:
        os.dup2(so_dup, so_fileno)
        os.close(so_dup)
    if _se_has_fileno:
        os.dup2(se_dup, se_fileno)
        os.close(se_dup)

    fout.close()
    fout = open_latin1(outfile, "r")
    text = fout.read()
    fout.close()
    os.remove(outfile)

    if using_command:
        ferr.close()
        ferr = open_latin1(errfile, "r")
        errmess = ferr.read()
        ferr.close()
        os.remove(errfile)
        if errmess and not status:
            # Not sure how to handle the case where errmess
            # contains only warning messages and that should
            # not be treated as errors.
            # status = 998
            if text:
                text = text + "\n"
            # text = '%sCOMMAND %r FAILED: %s' %(text,command,errmess)
            text = text + errmess
            print(errmess)
    if text[-1:] == "\n":
        text = text[:-1]
    if status is None:
        status = 0

    if use_tee:
        print(text)

    return status, text