| #!/usr/bin/env python | 
 |  | 
 | r""" | 
 | This module provides command execution functions such as cmd_fnc and cmd_fnc_u. | 
 | """ | 
 |  | 
 | import os | 
 | import sys | 
 | import subprocess | 
 | import collections | 
 | import signal | 
 | import time | 
 | import re | 
 | import inspect | 
 |  | 
 | import gen_print as gp | 
 | import gen_valid as gv | 
 | import gen_misc as gm | 
 | import func_args as fa | 
 |  | 
 | robot_env = gp.robot_env | 
 |  | 
 | if robot_env: | 
 |     from robot.libraries.BuiltIn import BuiltIn | 
 |  | 
 |  | 
 | # cmd_fnc and cmd_fnc_u should now be considered deprecated.  shell_cmd and t_shell_cmd should be used | 
 | # instead. | 
 | def cmd_fnc(cmd_buf, | 
 |             quiet=None, | 
 |             test_mode=None, | 
 |             debug=0, | 
 |             print_output=1, | 
 |             show_err=1, | 
 |             return_stderr=0, | 
 |             ignore_err=1): | 
 |     r""" | 
 |     Run the given command in a shell and return the shell return code and the output. | 
 |  | 
 |     Description of arguments: | 
 |     cmd_buf                         The command string to be run in a shell. | 
 |     quiet                           Indicates whether this function should run the print_issuing() function | 
 |                                     which prints "Issuing: <cmd string>" to stdout. | 
 |     test_mode                       If test_mode is set, this function will not actually run the command.  If | 
 |                                     print_output is set, it will print "(test_mode) Issuing: <cmd string>" to | 
 |                                     stdout. | 
 |     debug                           If debug is set, this function will print extra debug info. | 
 |     print_output                    If this is set, this function will print the stdout/stderr generated by | 
 |                                     the shell command. | 
 |     show_err                        If show_err is set, this function will print a standardized error report | 
 |                                     if the shell command returns non-zero. | 
 |     return_stderr                   If return_stderr is set, this function will process the stdout and stderr | 
 |                                     streams from the shell command separately.  It will also return stderr in | 
 |                                     addition to the return code and the stdout. | 
 |     """ | 
 |  | 
 |     # Determine default values. | 
 |     quiet = int(gm.global_default(quiet, 0)) | 
 |     test_mode = int(gm.global_default(test_mode, 0)) | 
 |  | 
 |     if debug: | 
 |         gp.print_vars(cmd_buf, quiet, test_mode, debug) | 
 |  | 
 |     err_msg = gv.valid_value(cmd_buf) | 
 |     if err_msg != "": | 
 |         raise ValueError(err_msg) | 
 |  | 
 |     if not quiet: | 
 |         gp.pissuing(cmd_buf, test_mode) | 
 |  | 
 |     if test_mode: | 
 |         if return_stderr: | 
 |             return 0, "", "" | 
 |         else: | 
 |             return 0, "" | 
 |  | 
 |     if return_stderr: | 
 |         err_buf = "" | 
 |         stderr = subprocess.PIPE | 
 |     else: | 
 |         stderr = subprocess.STDOUT | 
 |  | 
 |     sub_proc = subprocess.Popen(cmd_buf, | 
 |                                 bufsize=1, | 
 |                                 shell=True, | 
 |                                 executable='/bin/bash', | 
 |                                 stdout=subprocess.PIPE, | 
 |                                 stderr=stderr) | 
 |     out_buf = "" | 
 |     if return_stderr: | 
 |         for line in sub_proc.stderr: | 
 |             try: | 
 |                 err_buf += line | 
 |             except TypeError: | 
 |                 line = line.decode("utf-8") | 
 |                 err_buf += line | 
 |             if not print_output: | 
 |                 continue | 
 |             gp.gp_print(line) | 
 |     for line in sub_proc.stdout: | 
 |         try: | 
 |             out_buf += line | 
 |         except TypeError: | 
 |             line = line.decode("utf-8") | 
 |             out_buf += line | 
 |         if not print_output: | 
 |             continue | 
 |         gp.gp_print(line) | 
 |     if print_output and not robot_env: | 
 |         sys.stdout.flush() | 
 |     sub_proc.communicate() | 
 |     shell_rc = sub_proc.returncode | 
 |     if shell_rc != 0: | 
 |         err_msg = "The prior shell command failed.\n" | 
 |         err_msg += gp.sprint_var(shell_rc, gp.hexa()) | 
 |         if not print_output: | 
 |             err_msg += "out_buf:\n" + out_buf | 
 |  | 
 |         if show_err: | 
 |             gp.print_error_report(err_msg) | 
 |         if not ignore_err: | 
 |             if robot_env: | 
 |                 BuiltIn().fail(err_msg) | 
 |             else: | 
 |                 raise ValueError(err_msg) | 
 |  | 
 |     if return_stderr: | 
 |         return shell_rc, out_buf, err_buf | 
 |     else: | 
 |         return shell_rc, out_buf | 
 |  | 
 |  | 
 | def cmd_fnc_u(cmd_buf, | 
 |               quiet=None, | 
 |               debug=None, | 
 |               print_output=1, | 
 |               show_err=1, | 
 |               return_stderr=0, | 
 |               ignore_err=1): | 
 |     r""" | 
 |     Call cmd_fnc with test_mode=0.  See cmd_fnc (above) for details. | 
 |  | 
 |     Note the "u" in "cmd_fnc_u" stands for "unconditional". | 
 |     """ | 
 |  | 
 |     return cmd_fnc(cmd_buf, test_mode=0, quiet=quiet, debug=debug, | 
 |                    print_output=print_output, show_err=show_err, | 
 |                    return_stderr=return_stderr, ignore_err=ignore_err) | 
 |  | 
 |  | 
 | def parse_command_string(command_string): | 
 |     r""" | 
 |     Parse a bash command-line command string and return the result as a dictionary of parms. | 
 |  | 
 |     This can be useful for answering questions like "What did the user specify as the value for parm x in the | 
 |     command string?". | 
 |  | 
 |     This function expects the command string to follow the following posix conventions: | 
 |     - Short parameters: | 
 |       -<parm name><space><arg value> | 
 |     - Long parameters: | 
 |       --<parm name>=<arg value> | 
 |  | 
 |     The first item in the string will be considered to be the command.  All values not conforming to the | 
 |     specifications above will be considered positional parms.  If there are multiple parms with the same | 
 |     name, they will be put into a list (see illustration below where "-v" is specified multiple times). | 
 |  | 
 |     Description of argument(s): | 
 |     command_string                  The complete command string including all parameters and arguments. | 
 |  | 
 |     Sample input: | 
 |  | 
 |     robot_cmd_buf:                                    robot -v OPENBMC_HOST:dummy1 -v keyword_string:'Set | 
 |     Auto Reboot  no' -v lib_file_path:/home/user1/git/openbmc-test-automation/lib/utils.robot -v quiet:0 -v | 
 |     test_mode:0 -v debug:0 --outputdir='/home/user1/status/children/' | 
 |     --output=dummy1.Auto_reboot.170802.124544.output.xml --log=dummy1.Auto_reboot.170802.124544.log.html | 
 |     --report=dummy1.Auto_reboot.170802.124544.report.html | 
 |     /home/user1/git/openbmc-test-automation/extended/run_keyword.robot | 
 |  | 
 |     Sample output: | 
 |  | 
 |     robot_cmd_buf_dict: | 
 |       robot_cmd_buf_dict[command]:                    robot | 
 |       robot_cmd_buf_dict[v]: | 
 |         robot_cmd_buf_dict[v][0]:                     OPENBMC_HOST:dummy1 | 
 |         robot_cmd_buf_dict[v][1]:                     keyword_string:Set Auto Reboot no | 
 |         robot_cmd_buf_dict[v][2]: | 
 |         lib_file_path:/home/user1/git/openbmc-test-automation/lib/utils.robot | 
 |         robot_cmd_buf_dict[v][3]:                     quiet:0 | 
 |         robot_cmd_buf_dict[v][4]:                     test_mode:0 | 
 |         robot_cmd_buf_dict[v][5]:                     debug:0 | 
 |       robot_cmd_buf_dict[outputdir]:                  /home/user1/status/children/ | 
 |       robot_cmd_buf_dict[output]:                     dummy1.Auto_reboot.170802.124544.output.xml | 
 |       robot_cmd_buf_dict[log]:                        dummy1.Auto_reboot.170802.124544.log.html | 
 |       robot_cmd_buf_dict[report]:                     dummy1.Auto_reboot.170802.124544.report.html | 
 |       robot_cmd_buf_dict[positional]: | 
 |       /home/user1/git/openbmc-test-automation/extended/run_keyword.robot | 
 |     """ | 
 |  | 
 |     # We want the parms in the string broken down the way bash would do it, so we'll call upon bash to do | 
 |     # that by creating a simple inline bash function. | 
 |     bash_func_def = "function parse { for parm in \"${@}\" ; do" +\ | 
 |         " echo $parm ; done ; }" | 
 |  | 
 |     rc, outbuf = cmd_fnc_u(bash_func_def + " ; parse " + command_string, | 
 |                            quiet=1, print_output=0) | 
 |     command_string_list = outbuf.rstrip("\n").split("\n") | 
 |  | 
 |     command_string_dict = collections.OrderedDict() | 
 |     ix = 1 | 
 |     command_string_dict['command'] = command_string_list[0] | 
 |     while ix < len(command_string_list): | 
 |         if command_string_list[ix].startswith("--"): | 
 |             key, value = command_string_list[ix].split("=") | 
 |             key = key.lstrip("-") | 
 |         elif command_string_list[ix].startswith("-"): | 
 |             key = command_string_list[ix].lstrip("-") | 
 |             ix += 1 | 
 |             try: | 
 |                 value = command_string_list[ix] | 
 |             except IndexError: | 
 |                 value = "" | 
 |         else: | 
 |             key = 'positional' | 
 |             value = command_string_list[ix] | 
 |         if key in command_string_dict: | 
 |             if isinstance(command_string_dict[key], str): | 
 |                 command_string_dict[key] = [command_string_dict[key]] | 
 |             command_string_dict[key].append(value) | 
 |         else: | 
 |             command_string_dict[key] = value | 
 |         ix += 1 | 
 |  | 
 |     return command_string_dict | 
 |  | 
 |  | 
 | # Save the original SIGALRM handler for later restoration by shell_cmd. | 
 | original_sigalrm_handler = signal.getsignal(signal.SIGALRM) | 
 |  | 
 |  | 
 | def shell_cmd_timed_out(signal_number, | 
 |                         frame): | 
 |     r""" | 
 |     Handle an alarm signal generated during the shell_cmd function. | 
 |     """ | 
 |  | 
 |     gp.dprint_executing() | 
 |     global command_timed_out | 
 |     command_timed_out = True | 
 |     # Get subprocess pid from shell_cmd's call stack. | 
 |     sub_proc = gp.get_stack_var('sub_proc', 0) | 
 |     pid = sub_proc.pid | 
 |     gp.dprint_var(pid) | 
 |     # Terminate the child process group. | 
 |     os.killpg(pid, signal.SIGKILL) | 
 |     # Restore the original SIGALRM handler. | 
 |     signal.signal(signal.SIGALRM, original_sigalrm_handler) | 
 |  | 
 |     return | 
 |  | 
 |  | 
 | def shell_cmd(command_string, | 
 |               quiet=None, | 
 |               print_output=None, | 
 |               show_err=1, | 
 |               test_mode=0, | 
 |               time_out=None, | 
 |               max_attempts=1, | 
 |               retry_sleep_time=5, | 
 |               valid_rcs=[0], | 
 |               ignore_err=None, | 
 |               return_stderr=0, | 
 |               fork=0, | 
 |               error_regexes=None): | 
 |     r""" | 
 |     Run the given command string in a shell and return a tuple consisting of the shell return code and the | 
 |     output. | 
 |  | 
 |     Description of argument(s): | 
 |     command_string                  The command string to be run in a shell (e.g. "ls /tmp"). | 
 |     quiet                           If set to 0, this function will print "Issuing: <cmd string>" to stdout. | 
 |                                     When the quiet argument is set to None, this function will assign a | 
 |                                     default value by searching upward in the stack for the quiet variable | 
 |                                     value.  If no such value is found, quiet is set to 0. | 
 |     print_output                    If this is set, this function will print the stdout/stderr generated by | 
 |                                     the shell command to stdout. | 
 |     show_err                        If show_err is set, this function will print a standardized error report | 
 |                                     if the shell command fails (i.e. if the shell command returns a shell_rc | 
 |                                     that is not in valid_rcs).  Note: Error text is only printed if ALL | 
 |                                     attempts to run the command_string fail.  In other words, if the command | 
 |                                     execution is ultimately successful, initial failures are hidden. | 
 |     test_mode                       If test_mode is set, this function will not actually run the command.  If | 
 |                                     print_output is also set, this function will print "(test_mode) Issuing: | 
 |                                     <cmd string>" to stdout.  A caller should call shell_cmd directly if they | 
 |                                     wish to have the command string run unconditionally.  They should call | 
 |                                     the t_shell_cmd wrapper (defined below) if they wish to run the command | 
 |                                     string only if the prevailing test_mode variable is set to 0. | 
 |     time_out                        A time-out value expressed in seconds.  If the command string has not | 
 |                                     finished executing within <time_out> seconds, it will be halted and | 
 |                                     counted as an error. | 
 |     max_attempts                    The max number of attempts that should be made to run the command string. | 
 |     retry_sleep_time                The number of seconds to sleep between attempts. | 
 |     valid_rcs                       A list of integers indicating which shell_rc values are not to be | 
 |                                     considered errors. | 
 |     ignore_err                      Ignore error means that a failure encountered by running the command | 
 |                                     string will not be raised as a python exception.  When the ignore_err | 
 |                                     argument is set to None, this function will assign a default value by | 
 |                                     searching upward in the stack for the ignore_err variable value.  If no | 
 |                                     such value is found, ignore_err is set to 1. | 
 |     return_stderr                   If return_stderr is set, this function will process the stdout and stderr | 
 |                                     streams from the shell command separately.  In such a case, the tuple | 
 |                                     returned by this function will consist of three values rather than just | 
 |                                     two: rc, stdout, stderr. | 
 |     fork                            Run the command string asynchronously (i.e. don't wait for status of the | 
 |                                     child process and don't try to get stdout/stderr) and return the Popen | 
 |                                     object created by the subprocess.popen() function.  See the kill_cmd | 
 |                                     function for details on how to process the popen object. | 
 |     error_regexes                   A list of regular expressions to be used to identify errors in the | 
 |                                     command output.  If there is a match for any of these regular | 
 |                                     expressions, the command will be considered a failure and the shell_rc | 
 |                                     will be set to -1.  For example, if error_regexes = ['ERROR:'] and the | 
 |                                     command output contains 'ERROR:  Unrecognized option', it will be counted | 
 |                                     as an error even if the command returned 0.  This is useful when running | 
 |                                     commands that do not always return non-zero on error. | 
 |     """ | 
 |  | 
 |     err_msg = gv.valid_value(command_string) | 
 |     if err_msg: | 
 |         raise ValueError(err_msg) | 
 |  | 
 |     # Assign default values to some of the arguments to this function. | 
 |     quiet = int(gm.dft(quiet, gp.get_stack_var('quiet', 0))) | 
 |     print_output = int(gm.dft(print_output, not quiet)) | 
 |     show_err = int(show_err) | 
 |     ignore_err = int(gm.dft(ignore_err, gp.get_stack_var('ignore_err', 1))) | 
 |  | 
 |     gp.qprint_issuing(command_string, test_mode) | 
 |     if test_mode: | 
 |         return (0, "", "") if return_stderr else (0, "") | 
 |  | 
 |     # Convert a string python dictionary definition to a dictionary. | 
 |     valid_rcs = fa.source_to_object(valid_rcs) | 
 |     # Convert each list entry to a signed value. | 
 |     valid_rcs = [gm.to_signed(x) for x in valid_rcs] | 
 |  | 
 |     stderr = subprocess.PIPE if return_stderr else subprocess.STDOUT | 
 |  | 
 |     # Write all output to func_out_history_buf rather than directly to stdout.  This allows us to decide | 
 |     # what to print after all attempts to run the command string have been made.  func_out_history_buf will | 
 |     # contain the complete history from the current invocation of this function. | 
 |     global command_timed_out | 
 |     command_timed_out = False | 
 |     func_out_history_buf = "" | 
 |     for attempt_num in range(1, max_attempts + 1): | 
 |         sub_proc = subprocess.Popen(command_string, | 
 |                                     preexec_fn=os.setsid, | 
 |                                     bufsize=1, | 
 |                                     shell=True, | 
 |                                     universal_newlines=True, | 
 |                                     executable='/bin/bash', | 
 |                                     stdout=subprocess.PIPE, | 
 |                                     stderr=stderr) | 
 |         if fork: | 
 |             return sub_proc | 
 |  | 
 |         if time_out: | 
 |             command_timed_out = False | 
 |             # Designate a SIGALRM handling function and set alarm. | 
 |             signal.signal(signal.SIGALRM, shell_cmd_timed_out) | 
 |             signal.alarm(time_out) | 
 |         try: | 
 |             stdout_buf, stderr_buf = sub_proc.communicate() | 
 |         except IOError: | 
 |             command_timed_out = True | 
 |         # Restore the original SIGALRM handler and clear the alarm. | 
 |         signal.signal(signal.SIGALRM, original_sigalrm_handler) | 
 |         signal.alarm(0) | 
 |  | 
 |         # Output from this loop iteration is written to func_out_buf for later processing.  This can include | 
 |         # stdout, stderr and our own error messages. | 
 |         func_out_buf = "" | 
 |         if print_output: | 
 |             if return_stderr: | 
 |                 func_out_buf += stderr_buf | 
 |             func_out_buf += stdout_buf | 
 |         shell_rc = sub_proc.returncode | 
 |         if shell_rc in valid_rcs: | 
 |             # Check output for text indicating there is an error. | 
 |             if error_regexes and re.match('|'.join(error_regexes), stdout_buf): | 
 |                 shell_rc = -1 | 
 |             else: | 
 |                 break | 
 |         err_msg = "The prior shell command failed.\n" | 
 |         err_msg += gp.sprint_var(attempt_num) | 
 |         err_msg += gp.sprint_vars(command_string, command_timed_out, time_out) | 
 |         err_msg += gp.sprint_varx("child_pid", sub_proc.pid) | 
 |         err_msg += gp.sprint_vars(shell_rc, valid_rcs, fmt=gp.hexa()) | 
 |         if error_regexes: | 
 |             err_msg += gp.sprint_vars(error_regexes) | 
 |         if not print_output: | 
 |             if return_stderr: | 
 |                 err_msg += "stderr_buf:\n" + stderr_buf | 
 |             err_msg += "stdout_buf:\n" + stdout_buf | 
 |         if show_err: | 
 |             func_out_buf += gp.sprint_error_report(err_msg) | 
 |         if attempt_num < max_attempts: | 
 |             cmd_buf = "time.sleep(" + str(retry_sleep_time) + ")" | 
 |             if show_err: | 
 |                 func_out_buf += gp.sprint_issuing(cmd_buf) | 
 |             exec(cmd_buf) | 
 |         func_out_history_buf += func_out_buf | 
 |  | 
 |     if shell_rc in valid_rcs: | 
 |         gp.gp_print(func_out_buf) | 
 |     else: | 
 |         if show_err: | 
 |             gp.gp_print(func_out_history_buf, stream='stderr') | 
 |         else: | 
 |             # There is no error information to show so just print output from last loop iteration. | 
 |             gp.gp_print(func_out_buf) | 
 |         if not ignore_err: | 
 |             # If the caller has already asked to show error info, avoid repeating that in the failure message. | 
 |             err_msg = "The prior shell command failed.\n" if show_err \ | 
 |                 else err_msg | 
 |             if robot_env: | 
 |                 BuiltIn().fail(err_msg) | 
 |             else: | 
 |                 raise ValueError(err_msg) | 
 |  | 
 |     return (shell_rc, stdout_buf, stderr_buf) if return_stderr \ | 
 |         else (shell_rc, stdout_buf) | 
 |  | 
 |  | 
 | def t_shell_cmd(command_string, **kwargs): | 
 |     r""" | 
 |     Search upward in the the call stack to obtain the test_mode argument, add it to kwargs and then call | 
 |     shell_cmd and return the result. | 
 |  | 
 |     See shell_cmd prolog for details on all arguments. | 
 |     """ | 
 |  | 
 |     if 'test_mode' in kwargs: | 
 |         error_message = "Programmer error - test_mode is not a valid" +\ | 
 |             " argument to this function." | 
 |         gp.print_error_report(error_message) | 
 |         exit(1) | 
 |  | 
 |     test_mode = int(gp.get_stack_var('test_mode', 0)) | 
 |     kwargs['test_mode'] = test_mode | 
 |  | 
 |     return shell_cmd(command_string, **kwargs) | 
 |  | 
 |  | 
 | def kill_cmd(popen, sig=signal.SIGTERM): | 
 |     r""" | 
 |     Kill the subprocess represented by the Popen object and return a tuple consisting of the shell return | 
 |     code and the output. | 
 |  | 
 |     This function is meant to be used as the follow-up for a call to shell_cmd(..., fork=1). | 
 |  | 
 |     Example: | 
 |     popen = shell_cmd("some_pgm.py", fork=1) | 
 |     ... | 
 |     shell_rc, output = kill_cmd(popen) | 
 |  | 
 |     Description of argument(s): | 
 |     popen                           A Popen object returned by the subprocess.Popen() command. | 
 |     sig                             The signal to be sent to the child process. | 
 |     """ | 
 |  | 
 |     gp.dprint_var(popen.pid) | 
 |     os.killpg(popen.pid, sig) | 
 |     stdout, stderr = popen.communicate() | 
 |     shell_rc = popen.returncode | 
 |     return (shell_rc, stdout, stderr) if stderr else (shell_rc, stdout) | 
 |  | 
 |  | 
 | def re_order_kwargs(stack_frame_ix, **kwargs): | 
 |     r""" | 
 |     Re-order the kwargs to match the order in which they were specified on a function invocation and return | 
 |     as an ordered dictionary. | 
 |  | 
 |     Note that this re_order_kwargs function should not be necessary in python versions 3.6 and beyond. | 
 |  | 
 |     Example: | 
 |  | 
 |     The caller calls func1 like this: | 
 |  | 
 |     func1('mike', arg1='one', arg2='two', arg3='three') | 
 |  | 
 |     And func1 is defined as follows: | 
 |  | 
 |     def func1(first_arg, **kwargs): | 
 |  | 
 |         kwargs = re_order_kwargs(first_arg_num=2, stack_frame_ix=3, **kwargs) | 
 |  | 
 |     The kwargs dictionary before calling re_order_kwargs (where order is not guaranteed): | 
 |  | 
 |     kwargs: | 
 |       kwargs[arg3]:          three | 
 |       kwargs[arg2]:          two | 
 |       kwargs[arg1]:          one | 
 |  | 
 |     The kwargs dictionary after calling re_order_kwargs: | 
 |  | 
 |     kwargs: | 
 |       kwargs[arg1]:          one | 
 |       kwargs[arg2]:          two | 
 |       kwargs[arg3]:          three | 
 |  | 
 |     Note that the re-ordered kwargs match the order specified on the call to func1. | 
 |  | 
 |     Description of argument(s): | 
 |     stack_frame_ix                  The stack frame of the function whose kwargs values must be re-ordered. | 
 |                                     0 is the stack frame of re_order_kwargs, 1 is the stack from of its | 
 |                                     caller and so on. | 
 |     kwargs                          The keyword argument dictionary which is to be re-ordered. | 
 |     """ | 
 |  | 
 |     new_kwargs = collections.OrderedDict() | 
 |  | 
 |     # Get position number of first keyword on the calling line of code. | 
 |     (args, varargs, keywords, locals) =\ | 
 |         inspect.getargvalues(inspect.stack()[stack_frame_ix][0]) | 
 |     first_kwarg_pos = 1 + len(args) | 
 |     if varargs is not None: | 
 |         first_kwarg_pos += len(locals[varargs]) | 
 |     for arg_num in range(first_kwarg_pos, first_kwarg_pos + len(kwargs)): | 
 |         # This will result in an arg_name value such as "arg1='one'". | 
 |         arg_name = gp.get_arg_name(None, arg_num, stack_frame_ix + 2) | 
 |         # Continuing with the prior example, the following line will result | 
 |         # in key being set to 'arg1'. | 
 |         key = arg_name.split('=')[0] | 
 |         new_kwargs[key] = kwargs[key] | 
 |  | 
 |     return new_kwargs | 
 |  | 
 |  | 
 | def default_arg_delim(arg_dashes): | 
 |     r""" | 
 |     Return the default argument delimiter value for the given arg_dashes value. | 
 |  | 
 |     Note: this function is useful for functions that manipulate bash command line arguments (e.g. --parm=1 or | 
 |     -parm 1). | 
 |  | 
 |     Description of argument(s): | 
 |     arg_dashes                      The argument dashes specifier (usually, "-" or "--"). | 
 |     """ | 
 |  | 
 |     if arg_dashes == "--": | 
 |         return "=" | 
 |  | 
 |     return " " | 
 |  | 
 |  | 
 | def create_command_string(command, *pos_parms, **options): | 
 |     r""" | 
 |     Create and return a bash command string consisting of the given arguments formatted as text. | 
 |  | 
 |     The default formatting of options is as follows: | 
 |  | 
 |     <single dash><option name><space delim><option value> | 
 |  | 
 |     Example: | 
 |  | 
 |     -parm value | 
 |  | 
 |     The caller can change the kind of dashes/delimiters used by specifying "arg_dashes" and/or "arg_delims" | 
 |     as options.  These options are processed specially by the create_command_string function and do NOT get | 
 |     inserted into the resulting command string.  All options following the arg_dashes/arg_delims options will | 
 |     then use the specified values for dashes/delims.  In the special case of arg_dashes equal to "--", the | 
 |     arg_delim will automatically be changed to "=".  See examples below. | 
 |  | 
 |     Quoting rules: | 
 |  | 
 |     The create_command_string function will single quote option values as needed to prevent bash expansion. | 
 |     If the caller wishes to defeat this action, they may single or double quote the option value themselves. | 
 |     See examples below. | 
 |  | 
 |     pos_parms are NOT automatically quoted.  The caller is advised to either explicitly add quotes or to use | 
 |     the quote_bash_parm functions to quote any pos_parms. | 
 |  | 
 |     Examples: | 
 |  | 
 |     command_string = create_command_string('cd', '~') | 
 |  | 
 |     Result: | 
 |     cd ~ | 
 |  | 
 |     Note that the pos_parm ("~") does NOT get quoted, as per the aforementioned rules.  If quotes are | 
 |     desired, they may be added explicitly by the caller: | 
 |  | 
 |     command_string = create_command_string('cd', '\'~\'') | 
 |  | 
 |     Result: | 
 |     cd '~' | 
 |  | 
 |     command_string = create_command_string('grep', '\'^[^ ]*=\'', | 
 |         '/tmp/myfile', i=None, m='1', arg_dashes='--', color='always') | 
 |  | 
 |     Result: | 
 |     grep -i -m 1 --color=always '^[^ ]*=' /tmp/myfile | 
 |  | 
 |     In the preceding example, note the use of None to cause the "i" parm to be treated as a flag (i.e. no | 
 |     argument value is generated).  Also, note the use of arg_dashes to change the type of dashes used on all | 
 |     subsequent options.  The following example is equivalent to the prior.  Note that quote_bash_parm is used | 
 |     instead of including the quotes explicitly. | 
 |  | 
 |     command_string = create_command_string('grep', quote_bash_parm('^[^ ]*='), | 
 |         '/tmp/myfile', i=None,  m='1', arg_dashes='--', color='always') | 
 |  | 
 |     Result: | 
 |     grep -i -m 1 --color=always '^[^ ]*=' /tmp/myfile | 
 |  | 
 |     In the following example, note the automatic quoting of the password option, as per the aforementioned | 
 |     rules. | 
 |  | 
 |     command_string = create_command_string('my_pgm', '/tmp/myfile', i=None, | 
 |         m='1', arg_dashes='--', password='${my_pw}') | 
 |  | 
 |     However, let's say that the caller wishes to have bash expand the password value.  To achieve this, the | 
 |     caller can use double quotes: | 
 |  | 
 |     command_string = create_command_string('my_pgm', '/tmp/myfile', i=None, | 
 |         m='1', arg_dashes='--', password='"${my_pw}"') | 
 |  | 
 |     Result: | 
 |     my_pgm -i -m 1 --password="${my_pw}" /tmp/myfile | 
 |  | 
 |     command_string = create_command_string('ipmitool', 'power status', | 
 |         I='lanplus', C='3', 'p=623', U='root', P='0penBmc', H='xx.xx.xx.xx') | 
 |  | 
 |     Result: | 
 |     ipmitool -I lanplus -C 3 -p 623 -U root -P 0penBmc -H xx.xx.xx.xx power status | 
 |  | 
 |     By default create_command_string will take measures to preserve the order of the callers options.  In | 
 |     some cases, this effort may fail (as when calling directly from a robot program).  In this case, the | 
 |     caller can accept the responsibility of keeping an ordered list of options by calling this function with | 
 |     the last positional parm as some kind of dictionary (preferably an OrderedDict) and avoiding the use of | 
 |     any actual option args. | 
 |  | 
 |     Example: | 
 |     kwargs = collections.OrderedDict([('pass', 0), ('fail', 0)]) | 
 |     command_string = create_command_string('my program', 'pos_parm1', kwargs) | 
 |  | 
 |     Result: | 
 |  | 
 |     my program -pass 0 -fail 0 pos_parm1 | 
 |  | 
 |     Note to programmers who wish to write a wrapper to this function:  If the python version is less than | 
 |     3.6, to get the options to be processed correctly, the wrapper function must include a _stack_frame_ix_ | 
 |     keyword argument to allow this function to properly re-order options: | 
 |  | 
 |     def create_ipmi_ext_command_string(command, **kwargs): | 
 |  | 
 |         return create_command_string('ipmitool', command, _stack_frame_ix_=2, | 
 |             **kwargs) | 
 |  | 
 |     Example call of wrapper function: | 
 |  | 
 |     command_string = create_ipmi_ext_command_string('power status', I='lanplus') | 
 |  | 
 |     Description of argument(s): | 
 |     command                         The command (e.g. "cat", "sort", "ipmitool", etc.). | 
 |     pos_parms                       The positional parms for the command (e.g. PATTERN, FILENAME, etc.). | 
 |                                     These will be placed at the end of the resulting command string. | 
 |     options                         The command options (e.g. "-m 1", "--max-count=NUM", etc.).  Note that if | 
 |                                     the value of any option is None, then it will be understood to be a flag | 
 |                                     (for which no value is required). | 
 |     """ | 
 |  | 
 |     arg_dashes = "-" | 
 |     delim = default_arg_delim(arg_dashes) | 
 |  | 
 |     command_string = command | 
 |  | 
 |     if len(pos_parms) > 0 and gp.is_dict(pos_parms[-1]): | 
 |         # Convert pos_parms from tuple to list. | 
 |         pos_parms = list(pos_parms) | 
 |         # Re-assign options to be the last pos_parm value (which is a dictionary). | 
 |         options = pos_parms[-1] | 
 |         # Now delete the last pos_parm. | 
 |         del pos_parms[-1] | 
 |     else: | 
 |         # Either get stack_frame_ix from the caller via options or set it to the default value. | 
 |         stack_frame_ix = options.pop('_stack_frame_ix_', 1) | 
 |         if gm.python_version < gm.ordered_dict_version: | 
 |             # Re-establish the original options order as specified on the original line of code.  This | 
 |             # function depends on correct order. | 
 |             options = re_order_kwargs(stack_frame_ix, **options) | 
 |     for key, value in options.items(): | 
 |         # Check for special values in options and process them. | 
 |         if key == "arg_dashes": | 
 |             arg_dashes = str(value) | 
 |             delim = default_arg_delim(arg_dashes) | 
 |             continue | 
 |         if key == "arg_delim": | 
 |             delim = str(value) | 
 |             continue | 
 |         # Format the options elements into the command string. | 
 |         command_string += " " + arg_dashes + key | 
 |         if value is not None: | 
 |             command_string += delim | 
 |             if re.match(r'^(["].*["]|[\'].*[\'])$', str(value)): | 
 |                 # Already quoted. | 
 |                 command_string += str(value) | 
 |             else: | 
 |                 command_string += gm.quote_bash_parm(str(value)) | 
 |     # Finally, append the pos_parms to the end of the command_string.  Use filter to eliminate blank pos | 
 |     # parms. | 
 |     command_string = ' '.join([command_string] + list(filter(None, pos_parms))) | 
 |  | 
 |     return command_string |