39  * It should not be modified other than the package declaration above,

    40  * the copyright year and this comment.

    87     /**

    88      * Process the given environment variable and appends any Win32-style

    89      * command files for the specified command line arguments and return

    90      * the resulting arguments. A command file argument

    91      * is of the form '@file' where 'file' is the name of the file whose

    92      * contents are to be parsed for additional arguments. The contents of

    93      * the command file are parsed using StreamTokenizer and the original

    94      * '@file' argument replaced with the resulting tokens. Recursive command

    95      * files are not supported. The '@' character itself can be quoted with

    96      * the sequence '@@'.

    97      * @param envVariable the env variable to process

    98      * @param args the arguments that may contain @files

    99      * @return the arguments, with environment variable's content and expansion of @files

   100      * @throws IOException if there is a problem reading any of the @files

   101      * @throws UnmatchedQuote

   102      */

   103     public static List<String> parse(String envVariable, List<String> args)

   104             throws IOException, UnmatchedQuote {

   105 

   106         List<String> inArgs = new ArrayList<>();

   107         appendParsedEnvVariables(inArgs, envVariable);

   108         inArgs.addAll(args);

   109         List<String> newArgs = new ArrayList<>();

   110         appendParsedCommandArgs(newArgs, inArgs);

   111         return newArgs;

   112     }

   113 

   114     /**

   115      * Process the given environment variable and appends any Win32-style

   116      * command files for the specified command line arguments and return

   117      * the resulting arguments. A command file argument

   118      * is of the form '@file' where 'file' is the name of the file whose

   119      * contents are to be parsed for additional arguments. The contents of

   120      * the command file are parsed using StreamTokenizer and the original

   121      * '@file' argument replaced with the resulting tokens. Recursive command

   122      * files are not supported. The '@' character itself can be quoted with

   123      * the sequence '@@'.

   124      * @param envVariable the env variable to process

   125      * @param args the arguments that may contain @files

   126      * @return the arguments, with environment variable's content and expansion of @files

   127      * @throws IOException if there is a problem reading any of the @files

   128      * @throws UnmatchedQuote

   129      */

   130     public static String[] parse(String envVariable, String[] args) throws IOException, UnmatchedQuote {

   131         List<String> out = parse(envVariable, Arrays.asList(args));

   132         return out.toArray(new String[out.size()]);

   133     }

   134 

   252 

   253     @SuppressWarnings("fallthrough")

   254     private static void appendParsedEnvVariables(List<String> newArgs, String envVariable)

   255             throws UnmatchedQuote {

   256 

   257         if (envVariable == null) {

   258             return;

   259         }

   260         String in = System.getenv(envVariable);

   261         if (in == null || in.trim().isEmpty()) {

   262             return;

   263         }

   264 

   265         final char NUL = (char)0;

   266         final int len = in.length();

   267 

   268         int pos = 0;

   269         StringBuilder sb = new StringBuilder();

   270         char quote = NUL;

   271         char ch;

   272 

   273         loop:

   274         while (pos < len) {

   275             ch = in.charAt(pos);

   276             switch (ch) {

   277                 case '\"': case '\'':

   278                     if (quote == NUL) {

   279                         quote = ch;

   280                     } else if (quote == ch) {

   281                         quote = NUL;

   282                     } else {

   283                         sb.append(ch);

   284                     }

   285                     pos++;

   286                     break;

   287                 case '\f': case '\n': case '\r': case '\t': case ' ':

   288                     if (quote == NUL) {

   289                         newArgs.add(sb.toString());

   290                         sb.setLength(0);

   291                         while (ch == '\f' || ch == '\n' || ch == '\r' || ch == '\t' || ch == ' ') {

   292                             pos++;

   293                             if (pos >= len) {

   294                                 break loop;

   295                             }

   296                             ch = in.charAt(pos);

   297                         }

   298                         break;

   299                     }

   300                     // fall through

   301                 default:

   302                     sb.append(ch);

   303                     pos++;

   304             }

   305         }

   306         if (sb.length() != 0) {

   307             newArgs.add(sb.toString());

   308         }

   309         if (quote != NUL) {

   310             throw new UnmatchedQuote(envVariable);

   311         }

   312     }

   313 

   314     public static class UnmatchedQuote extends Exception {

   315         private static final long serialVersionUID = 0;

   316 

   317         public final String variableName;

   318 

   319         UnmatchedQuote(String variable) {

   320             this.variableName = variable;

   321         }

   322     }