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