Initial commit for plugin library

See spec at #1073.
2017-01-13 20:20:33 +08:00
parent 5ead55d67a
commit 1887c6ffb0
11 changed files with 522 additions and 45 deletions
@@ -0,0 +1,146 @@
+package com.github.shadowsocks.utils;
+
+import java.util.ArrayList;
+import java.util.StringTokenizer;
+
+/**
+ * Commandline objects help handling command lines specifying processes to
+ * execute.
+ *
+ * The class can be used to define a command line as nested elements or as a
+ * helper to define a command line by an application.
+ * <p>
+ * <code>
+ * &lt;someelement&gt;<br>
+ * &nbsp;&nbsp;&lt;acommandline executable="/executable/to/run"&gt;<br>
+ * &nbsp;&nbsp;&nbsp;&nbsp;&lt;argument value="argument 1" /&gt;<br>
+ * &nbsp;&nbsp;&nbsp;&nbsp;&lt;argument line="argument_1 argument_2 argument_3" /&gt;<br>
+ * &nbsp;&nbsp;&nbsp;&nbsp;&lt;argument value="argument 4" /&gt;<br>
+ * &nbsp;&nbsp;&lt;/acommandline&gt;<br>
+ * &lt;/someelement&gt;<br>
+ * </code>
+ *
+ * Based on: https://github.com/apache/ant/blob/588ce1f/src/main/org/apache/tools/ant/types/Commandline.java
+ *
+ * Adds support for escape character '\'.
+ *
+ * @author Mygod
+ */
+public final class Commandline {
+    private Commandline() { }
+
+    /**
+     * Quote the parts of the given array in way that makes them
+     * usable as command line arguments.
+     * @param line the list of arguments to quote.
+     * @return empty string for null or no command, else every argument split
+     * by spaces and quoted by quoting rules.
+     */
+    public static String toString(String[] line) {
+        // empty path return empty string
+        if (line == null || line.length == 0) {
+            return "";
+        }
+        // path containing one or more elements
+        final StringBuilder result = new StringBuilder();
+        for (int i = 0; i < line.length; i++) {
+            if (i > 0) {
+                result.append(' ');
+            }
+            for (int j = 0; j < line[i].length(); ++j) {
+                char ch = line[i].charAt(j);
+                switch (ch) {
+                    case ' ': case '\\': case '"': case '\'': result.append('\\');  // intentionally no break
+                    default: result.append(ch);
+                }
+            }
+        }
+        return result.toString();
+    }
+
+    /**
+     * Crack a command line.
+     * @param toProcess the command line to process.
+     * @return the command line broken into strings.
+     * An empty or null toProcess parameter results in a zero sized array.
+     */
+    public static String[] translateCommandline(String toProcess) {
+        if (toProcess == null || toProcess.length() == 0) {
+            //no command? no string
+            return new String[0];
+        }
+        // parse with a simple finite state machine
+
+        final int normal = 0;
+        final int inQuote = 1;
+        final int inDoubleQuote = 2;
+        int state = normal;
+        final StringTokenizer tok = new StringTokenizer(toProcess, "\\\"\' ", true);
+        final ArrayList<String> result = new ArrayList<>();
+        final StringBuilder current = new StringBuilder();
+        boolean lastTokenHasBeenQuoted = false;
+        boolean lastTokenIsSlash = false;
+
+        while (tok.hasMoreTokens()) {
+            String nextTok = tok.nextToken();
+            switch (state) {
+                case inQuote:
+                    if ("\'".equals(nextTok)) {
+                        lastTokenHasBeenQuoted = true;
+                        state = normal;
+                    } else {
+                        current.append(nextTok);
+                    }
+                    break;
+                case inDoubleQuote:
+                    if ("\"".equals(nextTok)) {
+                        if (lastTokenIsSlash) {
+                            current.append(nextTok);
+                            lastTokenIsSlash = false;
+                        } else {
+                            lastTokenHasBeenQuoted = true;
+                            state = normal;
+                        }
+                    } else if ("\\".equals(nextTok)) {
+                        if (lastTokenIsSlash) {
+                            current.append(nextTok);
+                            lastTokenIsSlash = false;
+                        } else lastTokenIsSlash = true;
+                    } else {
+                        if (lastTokenIsSlash) {
+                            current.append("\\");   // unescaped
+                            lastTokenIsSlash = false;
+                        }
+                        current.append(nextTok);
+                    }
+                    break;
+                default:
+                    if (lastTokenIsSlash) {
+                        current.append(nextTok);
+                        lastTokenIsSlash = false;
+                    } else if ("\\".equals(nextTok)) lastTokenIsSlash = true; else if ("\'".equals(nextTok)) {
+                        state = inQuote;
+                    } else if ("\"".equals(nextTok)) {
+                        state = inDoubleQuote;
+                    } else if (" ".equals(nextTok)) {
+                        if (lastTokenHasBeenQuoted || current.length() != 0) {
+                            result.add(current.toString());
+                            current.setLength(0);
+                        }
+                    } else {
+                        current.append(nextTok);
+                    }
+                    lastTokenHasBeenQuoted = false;
+                    break;
+            }
+        }
+        if (lastTokenHasBeenQuoted || current.length() != 0) {
+            result.add(current.toString());
+        }
+        if (state == inQuote || state == inDoubleQuote) {
+            throw new IllegalArgumentException("unbalanced quotes in " + toProcess);
+        }
+        if (lastTokenIsSlash) throw new IllegalArgumentException("escape character following nothing in " + toProcess);
+        return result.toArray(new String[result.size()]);
+    }
+}