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| 1 | +# Software License Agreement (BSD License) |
| 2 | +# |
| 3 | +# Copyright (c) 2008, Willow Garage, Inc. |
| 4 | +# All rights reserved. |
| 5 | +# |
| 6 | +# Redistribution and use in source and binary forms, with or without |
| 7 | +# modification, are permitted provided that the following conditions |
| 8 | +# are met: |
| 9 | +# |
| 10 | +# * Redistributions of source code must retain the above copyright |
| 11 | +# notice, this list of conditions and the following disclaimer. |
| 12 | +# * Redistributions in binary form must reproduce the above |
| 13 | +# copyright notice, this list of conditions and the following |
| 14 | +# disclaimer in the documentation and/or other materials provided |
| 15 | +# with the distribution. |
| 16 | +# * Neither the name of Willow Garage, Inc. nor the names of its |
| 17 | +# contributors may be used to endorse or promote products derived |
| 18 | +# from this software without specific prior written permission. |
| 19 | +# |
| 20 | +# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 21 | +# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 22 | +# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| 23 | +# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| 24 | +# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 25 | +# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| 26 | +# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| 27 | +# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| 28 | +# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 29 | +# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN |
| 30 | +# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 31 | +# POSSIBILITY OF SUCH DAMAGE. |
| 32 | +# |
| 33 | +# Revision $Id: substitution_args.py 15178 2011-10-10 21:22:53Z kwc $ |
| 34 | + |
| 35 | +""" |
| 36 | +Library for processing XML substitution args. |
| 37 | +""" |
| 38 | + |
| 39 | +import os |
| 40 | + |
| 41 | +try: |
| 42 | + from cStringIO import StringIO # Python 2.x |
| 43 | +except ImportError: |
| 44 | + from io import StringIO # Python 3.x |
| 45 | + |
| 46 | + |
| 47 | +class SubstitutionException(Exception): |
| 48 | + """ |
| 49 | + Base class for exceptions in substitution_args routines |
| 50 | + """ |
| 51 | + pass |
| 52 | +class ArgException(SubstitutionException): |
| 53 | + """ |
| 54 | + Exception for missing $(arg) values |
| 55 | + """ |
| 56 | + pass |
| 57 | + |
| 58 | +def _split_command(resolved, command_with_args): |
| 59 | + cmd = '$(%s)' % command_with_args |
| 60 | + idx1 = resolved.find(cmd) |
| 61 | + idx2 = idx1 + len(cmd) |
| 62 | + return resolved[0:idx1], resolved[idx2:] |
| 63 | + |
| 64 | + |
| 65 | +def _separate_first_path(value): |
| 66 | + idx = value.find(' ') |
| 67 | + if idx < 0: |
| 68 | + path, rest = value, '' |
| 69 | + else: |
| 70 | + path, rest = value[0:idx], value[idx:] |
| 71 | + return path, rest |
| 72 | + |
| 73 | + |
| 74 | +def _sanitize_path(path): |
| 75 | + path = path.replace('/', os.sep) |
| 76 | + path = path.replace('\\', os.sep) |
| 77 | + return path |
| 78 | + |
| 79 | + |
| 80 | +def _arg(resolved, a, args, context): |
| 81 | + """ |
| 82 | + process $(arg) arg |
| 83 | + |
| 84 | + :returns: updated resolved argument, ``str`` |
| 85 | + :raises: :exc:`ArgException` If arg invalidly specified |
| 86 | + """ |
| 87 | + if len(args) == 0: |
| 88 | + raise SubstitutionException("$(arg var) must specify an environment variable [%s]"%(a)) |
| 89 | + elif len(args) > 1: |
| 90 | + raise SubstitutionException("$(arg var) may only specify one arg [%s]"%(a)) |
| 91 | + |
| 92 | + if 'arg' not in context: |
| 93 | + context['arg'] = {} |
| 94 | + arg_context = context['arg'] |
| 95 | + |
| 96 | + arg_name = args[0] |
| 97 | + if arg_name in arg_context: |
| 98 | + arg_value = arg_context[arg_name] |
| 99 | + return resolved.replace("$(%s)"%a, arg_value) |
| 100 | + else: |
| 101 | + raise ArgException(arg_name) |
| 102 | + |
| 103 | + |
| 104 | +def resolve_args(arg_str, context=None, resolve_anon=True): |
| 105 | + """ |
| 106 | + Resolves substitution args (see wiki spec U{http://ros.org/wiki/roslaunch}). |
| 107 | +
|
| 108 | + @param arg_str: string to resolve zero or more substitution args |
| 109 | + in. arg_str may be None, in which case resolve_args will |
| 110 | + return None |
| 111 | + @type arg_str: str |
| 112 | + @param context dict: (optional) dictionary for storing results of |
| 113 | + the 'anon' and 'arg' substitution args. multiple calls to |
| 114 | + resolve_args should use the same context so that 'anon' |
| 115 | + substitions resolve consistently. If no context is provided, a |
| 116 | + new one will be created for each call. Values for the 'arg' |
| 117 | + context should be stored as a dictionary in the 'arg' key. |
| 118 | + @type context: dict |
| 119 | + @param resolve_anon bool: If True (default), will resolve $(anon |
| 120 | + foo). If false, will leave these args as-is. |
| 121 | + @type resolve_anon: bool |
| 122 | +
|
| 123 | + @return str: arg_str with substitution args resolved |
| 124 | + @rtype: str |
| 125 | + @raise SubstitutionException: if there is an error resolving substitution args |
| 126 | + """ |
| 127 | + if context is None: |
| 128 | + context = {} |
| 129 | + #parse found substitution args |
| 130 | + if not arg_str: |
| 131 | + return arg_str |
| 132 | + # first resolve variables like 'env' and 'arg' |
| 133 | + commands = { |
| 134 | + 'arg': _arg, |
| 135 | + } |
| 136 | + resolved = _resolve_args(arg_str, context, resolve_anon, commands) |
| 137 | + # than resolve 'find' as it requires the subsequent path to be expanded already |
| 138 | + |
| 139 | + resolved = _resolve_args(resolved, context, resolve_anon, commands) |
| 140 | + return resolved |
| 141 | + |
| 142 | +def _resolve_args(arg_str, context, resolve_anon, commands): |
| 143 | + valid = ['arg'] |
| 144 | + resolved = arg_str |
| 145 | + for a in _collect_args(arg_str): |
| 146 | + splits = [s for s in a.split(' ') if s] |
| 147 | + if not splits[0] in valid: |
| 148 | + raise SubstitutionException("Unknown substitution command [%s]. Valid commands are %s"%(a, valid)) |
| 149 | + command = splits[0] |
| 150 | + args = splits[1:] |
| 151 | + if command in commands: |
| 152 | + resolved = commands[command](resolved, a, args, context) |
| 153 | + return resolved |
| 154 | + |
| 155 | +_OUT = 0 |
| 156 | +_DOLLAR = 1 |
| 157 | +_LP = 2 |
| 158 | +_IN = 3 |
| 159 | +def _collect_args(arg_str): |
| 160 | + """ |
| 161 | + State-machine parser for resolve_args. Substitution args are of the form: |
| 162 | + $(find package_name)/scripts/foo.py $(export some/attribute blar) non-relevant stuff |
| 163 | + |
| 164 | + @param arg_str: argument string to parse args from |
| 165 | + @type arg_str: str |
| 166 | + @raise SubstitutionException: if args are invalidly specified |
| 167 | + @return: list of arguments |
| 168 | + @rtype: [str] |
| 169 | + """ |
| 170 | + buff = StringIO() |
| 171 | + args = [] |
| 172 | + state = _OUT |
| 173 | + for c in arg_str: |
| 174 | + # No escapes supported |
| 175 | + if c == '$': |
| 176 | + if state == _OUT: |
| 177 | + state = _DOLLAR |
| 178 | + elif state == _DOLLAR: |
| 179 | + pass |
| 180 | + else: |
| 181 | + raise SubstitutionException("Dollar signs '$' cannot be inside of substitution args [%s]"%arg_str) |
| 182 | + elif c == '(': |
| 183 | + if state == _DOLLAR: |
| 184 | + state = _LP |
| 185 | + elif state != _OUT: |
| 186 | + raise SubstitutionException("Invalid left parenthesis '(' in substitution args [%s]"%arg_str) |
| 187 | + elif c == ')': |
| 188 | + if state == _IN: |
| 189 | + #save contents of collected buffer |
| 190 | + args.append(buff.getvalue()) |
| 191 | + buff.truncate(0) |
| 192 | + buff.seek(0) |
| 193 | + state = _OUT |
| 194 | + else: |
| 195 | + state = _OUT |
| 196 | + elif state == _DOLLAR: |
| 197 | + # left paren must immediately follow dollar sign to enter _IN state |
| 198 | + state = _OUT |
| 199 | + elif state == _LP: |
| 200 | + state = _IN |
| 201 | + |
| 202 | + if state == _IN: |
| 203 | + buff.write(c) |
| 204 | + return args |
| 205 | + |
| 206 | + |
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