File: Synopsis/process.py
 1#
 2# Copyright (C) 2003 Stefan Seefeld
 3# All rights reserved.
 4# Licensed to the public under the terms of the GNU LGPL (>= 2),
 5# see the file COPYING for details.
 6#
 7
 8from Processor import Processor, Error
 9import IR
10from getoptions import get_options
11
12import sys
13
14def error(msg):
15    """Write an error message and exit."""
16    sys.stderr.write(msg)
17    sys.stderr.write('\n')
18    sys.exit(-1)
19
20def process(argv = sys.argv, **commands):
21    """Accept a set of commands and process according to command line options.
22    The typical call will start with the name of the processor to be executed,
23    followed by a set of parameters, followed by non-parameter arguments.
24    All parameters are either of the form 'name=value', or '--name=value'.
25    The first form expects 'value' to be valid python, the second a string.
26    The remaining non-parameter arguments are associated with the 'input'
27    parameter.
28    Once this initialization is done, the named command's 'process' method
29    is executed.
30    """
31
32    #first make sure the function was called with the correct argument types
33    for c in commands:
34        if not isinstance(commands[c], Processor):
35            error("command '%s' isn't a valid processor"%c)
36
37    if len(argv) < 2:
38        error("Usage : %s <command> [args] [input files]"%argv[0])
39
40    elif argv[1] == '--help':
41        print "Usage: %s --help"%argv[0]
42        print "   or: %s <command> --help"%argv[0]
43        print "   or: %s <command> [parameters]"%argv[0]
44        print ""
45        print "Available commands:"
46        for c in commands:
47            print "   %s"%c
48        sys.exit(0)
49
50    command = argv[1]
51    args = argv[2:]
52
53    if '--help' in args:
54        print "Parameters for command '%s'"%command
55        parameters = commands[command].get_parameters()
56        tab = max(map(lambda x:len(x), parameters.keys()))
57        for p in parameters:
58            print "   %-*s     %s"%(tab, p, parameters[p].doc)
59        sys.exit(0)
60
61    props = {}
62    # process all option arguments...
63    for o, a in get_options(args): props[o.replace('-', '_')] = a
64
65    # ...and keep remaining (non-option) arguments as 'input'
66    if args: props['input'] = args
67
68    if command in commands:
69        ir = IR.IR()
70        try:
71            commands[command].process(ir, **props)
72        except Error, e:
73            error(str(e))
74        except KeyboardInterrupt, e:
75            print 'KeyboardInterrupt'
76        except IOError, e:
77            error(str(e))
78    else:
79        error('no command "%s"'%command)
80
81