How to use the cup.shell.ShellExec function in cup

def _kill_child(pid, sign):
    cmd = 'ps -ef|grep %s|grep -v grep|awk \'{print $2,$3}\'' % (pid)
    ret = cup.shell.ShellExec().run(cmd, 10)
    pids = ret['stdout'].strip().split('\n')
    for proc in pids:
        p_id = proc.split()
        if p_id[1] == pid:
            _kill_child(p_id[0], sign)
        if p_id[0] == pid:
            if len(sign) == 0:
                cup.shell.execshell('kill %s' % pid)
            elif sign == '9' or sign == '-9':
                cup.shell.execshell('kill -9 %s' % pid)
            elif sign == 'SIGSTOP' or sign == '19' or sign == '-19':
                cup.shell.execshell('kill -19 %s' % pid)
            elif sign == 'SIGCONT' or sign == '18' or sign == '-18':
                cup.shell.execshell('kill -18 %s' % pid)
            else:
                cup.log.error('sign error')

exec working directory. Plz use
    :param tostr:
        recipt list, separated by ,
    :param subject:
        subject
    :param body:
        email content
    :param attach:
        email attachment
    :param content_is_html:
        is htm mode opened
    :return:
        return True on success, False otherwise
    """
    decorators.needlinux(mutt_sendmail)
    shellobj = shell.ShellExec()
    temp_cwd = os.getcwd()

    str_att = ''
    cmdstr = ''
    if attach == '':
        if content_is_html is True:
            cmdstr = 'echo "%s"|/usr/bin/mutt -e "my_hdr Content-Type:'\
                'text/html" -s "%s" %s' \
                % (body, subject, tostr)
        else:
            cmdstr = 'echo "%s"|/usr/bin/mutt -s "%s" %s' % (
                body, subject, tostr
            )
    else:
        attlist = attach.strip().split(',')
        attlen = len(attlist)

:return:
        return None if not found. Otherwise, return the pid

    """
    cmd = (
        'ps -ef|grep \'%s\'|grep -v grep|grep -vwE "vim |less |vi |tail |cat |more "'
        '|awk \'{print $2}\''
    ) % (grep_string)
    ret = cup.shell.ShellExec().run(cmd, 10)
    pids = ret['stdout'].strip().split('\n')
    if len(pids) == 0 or len(pids) == 1 and len(pids[0]) == 0:
        return None
    for pid in pids:
        for sel_path in ["cwd", "exe"]:
            cmd = 'ls -l /proc/%s/%s|awk \'{print $11}\' ' % (pid, sel_path)
            ret = cup.shell.ShellExec().run(cmd, 10)
            pid_path = ret['stdout'].strip().strip()
            if pid_path.find(process_path) == 0:
                return pid
    return None

    @decorators.needlinux
    def __is_port_used(port):
        """internal func"""
        cmd = "netstat -nl | grep ':%s '" % (port)
        ret = cup.shell.ShellExec().run(cmd, 10)
        if 0 != ret['returncode']:
            return False
        stdout = ret['stdout'].strip()
        if 0 == len(stdout):
            return False
        else:
            return True
    return __is_port_used(port)

def updatekv(self, confpath, key, val):
        """
        update key with value
        """
        cmd = "%s -c %s -u %s:%s " % (self._modtool, confpath, key, val)
        try_times = 0
        while True:
            ret = cup.shell.ShellExec().run(cmd, 120)
            if(
                ret['returncode'] == 0
                or not ret['returncode']
                or try_times > 1
            ):
                ret['stdout'] = ret['stdout'].decode('gbk')
                ret['stdout'] = ret['stdout'].encode('utf-8')
                # print ret['stdout']
                break
            else:
                try_times += 1
                print('err:updatekv')
                time.sleep(1)

def addkv(self, confpath, key, val):
        """
        add key value into a conf
        """
        cmd = "%s -c %s -i %s:%s &>/dev/null" % (
            self._modtool, confpath, key, val
        )
        try_times = 0
        while True:
            ret = cup.shell.ShellExec().run(cmd, 120)
            if(
                ret['returncode'] == 0
                or not ret['returncode']
                or try_times > 1
            ):
                ret['stdout'] = ret['stdout'].decode('gbk')
                ret['stdout'] = ret['stdout'].encode('utf-8')
                print(ret['stdout'])
                break
            else:
                try_times += 1
                print('err:addkv')
                time.sleep(1)

            if(ret == 0 or try_times > 1):
                print(cmd)

def delkv(self, confpath, key):
        """
        del a key from a conf file
        """
        cmd = "%s -c %s -d %s " % (self._modtool, confpath, key)
        try_times = 0
        while True:
            ret = cup.shell.ShellExec().run(cmd, 120)
            if(
                ret['returncode'] == 0
                or not ret['returncode']
                or try_times > 1
            ):
                ret['stdout'] = ret['stdout'].decode('gbk')
                ret['stdout'] = ret['stdout'].encode('utf-8')
                print(ret['stdout'])
                break
            else:
                try_times += 1
                print('err:delkv')
                time.sleep(1)

            if(ret == 0 or try_times > 1):
                print(cmd)