1#!/usr/bin/env python
2
3r"""
4This module provides valuable argument processing functions like
5gen_get_options and sprint_args.
6"""
7
8import sys
9import __builtin__
10import atexit
11import signal
12import argparse
13
14import gen_print as gp
15
16default_string = '  The default value is "%(default)s".'
17
18
19def gen_get_options(parser,
20                    stock_list=[]):
21
22    r"""
23    Parse the command line arguments using the parser object passed and return
24    True/False (i.e. pass/fail).  Also set the following built in values:
25
26    __builtin__.quiet      This value is used by the qprint functions.
27    __builtin__.test_mode  This value is used by command processing functions.
28    __builtin__.debug      This value is used by the dprint functions.
29    __builtin__.arg_obj    This value is used by print_program_header, etc.
30    __builtin__.parser     This value is used by print_program_header, etc.
31
32    Description of arguments:
33    parser                          A parser object.  See argparse module
34                                    documentation for details.
35    stock_list                      The caller can use this parameter to
36                                    request certain stock parameters offered
37                                    by this function.  For example, this
38                                    function will define a "quiet" option upon
39                                    request.  This includes stop help text and
40                                    parm checking.  The stock_list is a list
41                                    of tuples each of which consists of an
42                                    arg_name and a default value.  Example:
43                                    stock_list = [("test_mode", 0), ("quiet",
44                                    1), ("debug", 0)]
45    """
46
47    # This is a list of stock parms that we support.
48    master_stock_list = ["quiet", "test_mode", "debug", "loglevel"]
49
50    # Process stock_list.
51    for ix in range(0, len(stock_list)):
52        if len(stock_list[ix]) < 1:
53            gp.print_error_report("Programmer error - stock_list[" + str(ix) +
54                                  "] is supposed to be a tuple containing at" +
55                                  " least one element which is the name of" +
56                                  " the desired stock parameter:\n" +
57                                  gp.sprint_var(stock_list))
58            return False
59        if type(stock_list[ix]) is tuple:
60            arg_name = stock_list[ix][0]
61            default = stock_list[ix][1]
62        else:
63            arg_name = stock_list[ix]
64            default = None
65
66        if arg_name not in master_stock_list:
67            gp.pvar(arg_name)
68            gp.print_error_report("Programmer error - \"" + arg_name +
69                                  "\" not found found in stock list:\n" +
70                                  gp.sprint_var(master_stock_list))
71            return False
72
73        if arg_name == "quiet":
74            if default is None:
75                default = 0
76            parser.add_argument(
77                '--quiet',
78                default=default,
79                type=int,
80                choices=[1, 0],
81                help='If this parameter is set to "1", %(prog)s' +
82                     ' will print only essential information, i.e. it will' +
83                     ' not echo parameters, echo commands, print the total' +
84                     ' run time, etc.' + default_string)
85        elif arg_name == "test_mode":
86            if default is None:
87                default = 0
88            parser.add_argument(
89                '--test_mode',
90                default=default,
91                type=int,
92                choices=[1, 0],
93                help='This means that %(prog)s should go through all the' +
94                     ' motions but not actually do anything substantial.' +
95                     '  This is mainly to be used by the developer of' +
96                     ' %(prog)s.' + default_string)
97        elif arg_name == "debug":
98            if default is None:
99                default = 0
100            parser.add_argument(
101                '--debug',
102                default=default,
103                type=int,
104                choices=[1, 0],
105                help='If this parameter is set to "1", %(prog)s will print' +
106                     ' additional debug information.  This is mainly to be' +
107                     ' used by the developer of %(prog)s.' + default_string)
108        elif arg_name == "loglevel":
109            if default is None:
110                default = "info"
111            parser.add_argument(
112                '--loglevel',
113                default=default,
114                type=str,
115                choices=['DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL',
116                         'debug', 'info', 'warning', 'error', 'critical'],
117                help='If this parameter is set to "1", %(prog)s will print' +
118                     ' additional debug information.  This is mainly to be' +
119                     ' used by the developer of %(prog)s.' + default_string)
120
121    arg_obj = parser.parse_args()
122
123    __builtin__.quiet = 0
124    __builtin__.test_mode = 0
125    __builtin__.debug = 0
126    __builtin__.loglevel = 'WARNING'
127    for ix in range(0, len(stock_list)):
128        if type(stock_list[ix]) is tuple:
129            arg_name = stock_list[ix][0]
130            default = stock_list[ix][1]
131        else:
132            arg_name = stock_list[ix]
133            default = None
134        if arg_name == "quiet":
135            __builtin__.quiet = arg_obj.quiet
136        elif arg_name == "test_mode":
137            __builtin__.test_mode = arg_obj.test_mode
138        elif arg_name == "debug":
139            __builtin__.debug = arg_obj.debug
140        elif arg_name == "loglevel":
141            __builtin__.loglevel = arg_obj.loglevel
142
143    __builtin__.arg_obj = arg_obj
144    __builtin__.parser = parser
145
146    # For each command line parameter, create a corresponding global variable
147    # and assign it the appropriate value.  For example, if the command line
148    # contained "--last_name='Smith', we'll create a global variable named
149    # "last_name" with the value "Smith".
150    module = sys.modules['__main__']
151    for key in arg_obj.__dict__:
152        setattr(module, key, getattr(__builtin__.arg_obj, key))
153
154    return True
155
156
157def set_pgm_arg(var_value,
158                var_name=None):
159
160    r"""
161    Set the value of the arg_obj.__dict__ entry named in var_name with the
162    var_value provided.  Also, set corresponding global variable.
163
164    Description of arguments:
165    var_value                       The value to set in the variable.
166    var_name                        The name of the variable to set.  This
167                                    defaults to the name of the variable used
168                                    for var_value when calling this function.
169    """
170
171    if var_name is None:
172        var_name = gp.get_arg_name(None, 1, 2)
173
174    arg_obj.__dict__[var_name] = var_value
175    module = sys.modules['__main__']
176    setattr(module, var_name, var_value)
177    if var_name == "quiet":
178        __builtin__.quiet = var_value
179    elif var_name == "debug":
180        __builtin__.debug = var_value
181    elif var_name == "test_mode":
182        __builtin__.test_mode = var_value
183
184
185# Put this in gen_opt.py or gen_parm.py or gen_arg.py.
186def sprint_args(arg_obj,
187                indent=0):
188
189    r"""
190    sprint_var all of the arguments found in arg_obj and return the result as
191    a string.
192
193    Description of arguments:
194    arg_obj                         An argument object such as is returned by
195                                    the argparse parse_args() method.
196    indent                          The number of spaces to indent each line
197                                    of output.
198    """
199
200    loc_col1_width = gp.col1_width + indent
201
202    buffer = ""
203
204    for key in arg_obj.__dict__:
205        buffer += gp.sprint_varx(key, getattr(arg_obj, key), 0, indent,
206                                 loc_col1_width)
207
208    return buffer
209
210
211def gen_post_validation(exit_function=None,
212                        signal_handler=None):
213
214    r"""
215    Do generic post-validation processing.  By "post", we mean that this is to
216    be called from a validation function after the caller has done any
217    validation desired.  If the calling program passes exit_function and
218    signal_handler parms, this function will register them.  In other words,
219    it will make the signal_handler functions get called for SIGINT and
220    SIGTERM and will make the exit_function function run prior to the
221    termination of the program.
222
223    Description of arguments:
224    exit_function                   A function object pointing to the caller's
225                                    exit function.
226    signal_handler                  A function object pointing to the caller's
227                                    signal_handler function.
228    """
229
230    if exit_function is not None:
231        atexit.register(exit_function)
232    if signal_handler is not None:
233        signal.signal(signal.SIGINT, signal_handler)
234        signal.signal(signal.SIGTERM, signal_handler)
235