Update from Google.
--
MOE_MIGRATED_REVID=85702957
diff --git a/src/main/java/com/google/devtools/build/lib/shell/ShellUtils.java b/src/main/java/com/google/devtools/build/lib/shell/ShellUtils.java
new file mode 100644
index 0000000..5157f34
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/shell/ShellUtils.java
@@ -0,0 +1,145 @@
+// Copyright 2014 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.devtools.build.lib.shell;
+
+import java.util.List;
+
+/**
+ * Utility functions for Bourne shell commands, including escaping and
+ * tokenizing.
+ */
+public abstract class ShellUtils {
+
+ private ShellUtils() {}
+
+ /**
+ * Characters that have no special meaning to the shell.
+ */
+ private static final String SAFE_PUNCTUATION = "@%-_+:,./";
+
+ /**
+ * Quotes a word so that it can be used, without further quoting,
+ * as an argument (or part of an argument) in a shell command.
+ */
+ public static String shellEscape(String word) {
+ int len = word.length();
+ if (len == 0) {
+ // Empty string is a special case: needs to be quoted to ensure that it gets
+ // treated as a separate argument.
+ return "''";
+ }
+ for (int ii = 0; ii < len; ii++) {
+ char c = word.charAt(ii);
+ // We do this positively so as to be sure we don't inadvertently forget
+ // any unsafe characters.
+ if (!Character.isLetterOrDigit(c) && SAFE_PUNCTUATION.indexOf(c) == -1) {
+ // replace() actually means "replace all".
+ return "'" + word.replace("'", "'\\''") + "'";
+ }
+ }
+ return word;
+ }
+
+ /**
+ * Given an argv array such as might be passed to execve(2), returns a string
+ * that can be copied and pasted into a Bourne shell for a similar effect.
+ */
+ public static String prettyPrintArgv(List<String> argv) {
+ StringBuilder buf = new StringBuilder();
+ for (String arg: argv) {
+ if (buf.length() > 0) {
+ buf.append(' ');
+ }
+ buf.append(shellEscape(arg));
+ }
+ return buf.toString();
+ }
+
+
+ /**
+ * Thrown by tokenize method if there is an error
+ */
+ public static class TokenizationException extends Exception {
+ TokenizationException(String message) {
+ super(message);
+ }
+ }
+
+ /**
+ * Populates the passed list of command-line options extracted from {@code
+ * optionString}, which is a string containing multiple options, delimited in
+ * a Bourne shell-like manner.
+ *
+ * @param options the list to be populated with tokens.
+ * @param optionString the string to be tokenized.
+ * @throws TokenizationException if there was an error (such as an
+ * unterminated quotation).
+ */
+ public static void tokenize(List<String> options, String optionString)
+ throws TokenizationException {
+ // See test suite for examples.
+ //
+ // Note: backslash escapes the following character, except within a
+ // single-quoted region where it is literal.
+
+ StringBuilder token = new StringBuilder();
+ boolean forceToken = false;
+ char quotation = '\0'; // NUL, '\'' or '"'
+ for (int ii = 0, len = optionString.length(); ii < len; ii++) {
+ char c = optionString.charAt(ii);
+ if (quotation != '\0') { // in quotation
+ if (c == quotation) { // end of quotation
+ quotation = '\0';
+ } else if (c == '\\' && quotation == '"') { // backslash in "-quotation
+ if (++ii == len) {
+ throw new TokenizationException("backslash at end of string");
+ }
+ c = optionString.charAt(ii);
+ if (c != '\\' && c != '"') {
+ token.append('\\');
+ }
+ token.append(c);
+ } else { // regular char, in quotation
+ token.append(c);
+ }
+ } else { // not in quotation
+ if (c == '\'' || c == '"') { // begin single/double quotation
+ quotation = c;
+ forceToken = true;
+ } else if (c == ' ' || c == '\t') { // space, not quoted
+ if (forceToken || token.length() > 0) {
+ options.add(token.toString());
+ token = new StringBuilder();
+ forceToken = false;
+ }
+ } else if (c == '\\') { // backslash, not quoted
+ if (++ii == len) {
+ throw new TokenizationException("backslash at end of string");
+ }
+ token.append(optionString.charAt(ii));
+ } else { // regular char, not quoted
+ token.append(c);
+ }
+ }
+ }
+ if (quotation != '\0') {
+ throw new TokenizationException("unterminated quotation");
+ }
+ if (forceToken || token.length() > 0) {
+ options.add(token.toString());
+ }
+ }
+
+}