1#!/usr/bin/env python3
2
3r"""
4See help text for details (--help or -h option)..
5
6Example properties file content:
7quiet=n
8test_mode=y
9pos=file1 file2 file3
10
11Example call:
12
13prop_call.py --prop_file_name=prop_file my_program
14
15The result is that the following command will be run:
16my_program --test_mode=y --quiet=n file1 file2 file3
17"""
18
19from gen_arg import *
20from gen_print import *
21from gen_valid import *
22from gen_misc import *
23from gen_cmd import *
24
25import sys
26import os
27
28save_path_0 = sys.path[0]
29del sys.path[0]
30
31# Restore sys.path[0].
32sys.path.insert(0, save_path_0)
33
34
35parser = argparse.ArgumentParser(
36    usage='%(prog)s [OPTIONS]',
37    description="%(prog)s will call a program using parameters retrieved"
38    + " from the given properties file.",
39    formatter_class=argparse.ArgumentDefaultsHelpFormatter,
40    prefix_chars='-+')
41
42parser.add_argument(
43    '--prop_dir_path',
44    default=os.environ.get("PROP_DIR_PATH", os.getcwd()),
45    help='The path to the directory that contains the properties file.'
46    + '  The default value is environment variable "PROP_DIR_PATH", if'
47    + ' set.  Otherwise, it is the current working directory.')
48
49parser.add_argument(
50    '--prop_file_name',
51    help='The path to a properties file that contains the parameters to'
52    + ' pass to the program.  If the properties file has a ".properties"'
53    + ' extension, the caller need not specify the extension.  The format'
54    + ' of each line in the properties file should be as follows:'
55    + ' <parm_name=parm_value>.  Do not quote the parm value.  To specify'
56    + ' positional parms, use a parm name of "pos".  For example: pos=this'
57    ' value')
58
59parser.add_argument(
60    'program_name',
61    help='The name of the program to be run.')
62
63# Populate stock_list with options we want.
64stock_list = [("test_mode", 0), ("quiet", 1), ("debug", 0)]
65
66
67def exit_function(signal_number=0,
68                  frame=None):
69    r"""
70    Execute whenever the program ends normally or with the signals that we catch (i.e. TERM, INT).
71    """
72
73    dprint_executing()
74    dprint_var(signal_number)
75
76    qprint_pgm_footer()
77
78
79def signal_handler(signal_number,
80                   frame):
81    r"""
82    Handle signals.  Without a function to catch a SIGTERM or SIGINT, our program would terminate immediately
83    with return code 143 and without calling our exit_function.
84    """
85
86    # Our convention is to set up exit_function with atexit.register() so there is no need to explicitly
87    # call exit_function from here.
88
89    dprint_executing()
90
91    # Calling exit prevents us from returning to the code that was running when we received the signal.
92    exit(0)
93
94
95def validate_parms():
96    r"""
97    Validate program parameters, etc.  Return True or False (i.e. pass/fail) accordingly.
98    """
99
100    global prop_dir_path
101    global prop_file_path
102
103    if not valid_dir_path(prop_dir_path):
104        return False
105    prop_dir_path = add_trailing_slash(prop_dir_path)
106
107    if not valid_value(prop_file_name):
108        return False
109
110    prop_file_path = prop_dir_path + prop_file_name
111
112    # If properties file is not found, try adding ".properties" extension.
113    if not os.path.isfile(prop_file_path):
114        alt_prop_file_path = prop_file_path + ".properties"
115        if os.path.isfile(alt_prop_file_path):
116            prop_file_path = alt_prop_file_path
117
118    if not valid_file_path(prop_file_path):
119        return False
120
121    if not valid_value(program_name):
122        return False
123
124    gen_post_validation(exit_function, signal_handler)
125
126    return True
127
128
129def main():
130
131    if not gen_get_options(parser, stock_list):
132        return False
133
134    if not validate_parms():
135        return False
136
137    qprint_pgm_header()
138
139    # Get the parameters from the properties file.
140    properties = my_parm_file(prop_file_path)
141    # The parms (including program name) need to go into a list.
142    parms = [program_name]
143    for key, value in properties.items():
144        if key == "pos":
145            # Process positional parm(s).
146            parms.extend(value.split())
147        else:
148            parms.append("--" + key + "=" + escape_bash_quotes(value))
149
150    # parm_string is only created for display in non-quiet mode.
151    parm_string = " ".join(parms[1:])
152    cmd_buf = program_name + " " + parm_string
153    qprint_issuing(cmd_buf)
154    if not test_mode:
155        os.execvp(program_name, parms)
156
157    return True
158
159
160# Main
161
162if not main():
163    exit(1)
164