ScriptingFunctions.java revision 1407:ad3c4bdf0cf6
1/* 2 * Copyright (c) 2010, 2015, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26package jdk.nashorn.internal.runtime; 27 28import static jdk.nashorn.internal.lookup.Lookup.MH; 29import static jdk.nashorn.internal.runtime.ECMAErrors.rangeError; 30import static jdk.nashorn.internal.runtime.ECMAErrors.typeError; 31import static jdk.nashorn.internal.runtime.ScriptRuntime.UNDEFINED; 32 33import java.io.BufferedReader; 34import java.io.File; 35import java.io.IOException; 36import java.io.InputStreamReader; 37import java.io.OutputStreamWriter; 38import java.io.StreamTokenizer; 39import java.io.StringReader; 40import java.lang.invoke.MethodHandle; 41import java.lang.invoke.MethodHandles; 42import java.util.ArrayList; 43import java.util.Arrays; 44import java.util.List; 45import java.util.Map; 46import jdk.nashorn.internal.objects.NativeArray; 47 48/** 49 * Global functions supported only in scripting mode. 50 */ 51public final class ScriptingFunctions { 52 53 /** Handle to implementation of {@link ScriptingFunctions#readLine} - Nashorn extension */ 54 public static final MethodHandle READLINE = findOwnMH("readLine", Object.class, Object.class, Object.class); 55 56 /** Handle to implementation of {@link ScriptingFunctions#readFully} - Nashorn extension */ 57 public static final MethodHandle READFULLY = findOwnMH("readFully", Object.class, Object.class, Object.class); 58 59 /** Handle to implementation of {@link ScriptingFunctions#exec} - Nashorn extension */ 60 public static final MethodHandle EXEC = findOwnMH("exec", Object.class, Object.class, Object[].class); 61 62 /** EXEC name - special property used by $EXEC API. */ 63 public static final String EXEC_NAME = "$EXEC"; 64 65 /** OUT name - special property used by $EXEC API. */ 66 public static final String OUT_NAME = "$OUT"; 67 68 /** ERR name - special property used by $EXEC API. */ 69 public static final String ERR_NAME = "$ERR"; 70 71 /** EXIT name - special property used by $EXEC API. */ 72 public static final String EXIT_NAME = "$EXIT"; 73 74 /** THROW_ON_ERROR name - special property of the $EXEC function used by $EXEC API. */ 75 public static final String THROW_ON_ERROR_NAME = "throwOnError"; 76 77 /** Names of special properties used by $ENV API. */ 78 public static final String ENV_NAME = "$ENV"; 79 80 /** Name of the environment variable for the current working directory. */ 81 public static final String PWD_NAME = "PWD"; 82 83 private ScriptingFunctions() { 84 } 85 86 /** 87 * Nashorn extension: global.readLine (scripting-mode-only) 88 * Read one line of input from the standard input. 89 * 90 * @param self self reference 91 * @param prompt String used as input prompt 92 * 93 * @return line that was read 94 * 95 * @throws IOException if an exception occurs 96 */ 97 public static Object readLine(final Object self, final Object prompt) throws IOException { 98 if (prompt != UNDEFINED) { 99 System.out.print(JSType.toString(prompt)); 100 } 101 final BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); 102 return reader.readLine(); 103 } 104 105 /** 106 * Nashorn extension: Read the entire contents of a text file and return as String. 107 * 108 * @param self self reference 109 * @param file The input file whose content is read. 110 * 111 * @return String content of the input file. 112 * 113 * @throws IOException if an exception occurs 114 */ 115 public static Object readFully(final Object self, final Object file) throws IOException { 116 File f = null; 117 118 if (file instanceof File) { 119 f = (File)file; 120 } else if (JSType.isString(file)) { 121 f = new java.io.File(((CharSequence)file).toString()); 122 } 123 124 if (f == null || !f.isFile()) { 125 throw typeError("not.a.file", ScriptRuntime.safeToString(file)); 126 } 127 128 return new String(Source.readFully(f)); 129 } 130 131 /** 132 * Nashorn extension: exec a string in a separate process. 133 * 134 * @param self self reference 135 * @param args string to execute, input and additional arguments, to be appended to {@code string}. Additional 136 * arguments can be passed as either one JavaScript array, whose elements will be converted to 137 * strings; or as a sequence of varargs, each of which will be converted to a string. 138 * 139 * @return output string from the request 140 * 141 * @throws IOException if any stream access fails 142 * @throws InterruptedException if execution is interrupted 143 */ 144 public static Object exec(final Object self, final Object... args) throws IOException, InterruptedException { 145 // Current global is need to fetch additional inputs and for additional results. 146 final ScriptObject global = Context.getGlobal(); 147 final Object string = args.length > 0? args[0] : UNDEFINED; 148 final Object input = args.length > 1? args[1] : UNDEFINED; 149 final Object[] argv = (args.length > 2)? Arrays.copyOfRange(args, 2, args.length) : ScriptRuntime.EMPTY_ARRAY; 150 // Assemble command line, process additional arguments. 151 final List<String> cmdLine = tokenizeString(JSType.toString(string)); 152 final Object[] additionalArgs = argv.length == 1 && argv[0] instanceof NativeArray ? 153 ((NativeArray) argv[0]).asObjectArray() : 154 argv; 155 for (Object arg : additionalArgs) { 156 cmdLine.add(JSType.toString(arg)); 157 } 158 159 // Set up initial process. 160 final ProcessBuilder processBuilder = new ProcessBuilder(cmdLine); 161 162 // Current ENV property state. 163 final Object env = global.get(ENV_NAME); 164 if (env instanceof ScriptObject) { 165 final ScriptObject envProperties = (ScriptObject)env; 166 167 // If a working directory is present, use it. 168 final Object pwd = envProperties.get(PWD_NAME); 169 if (pwd != UNDEFINED) { 170 final File pwdFile = new File(JSType.toString(pwd)); 171 if (pwdFile.exists()) { 172 processBuilder.directory(pwdFile); 173 } 174 } 175 176 // Set up ENV variables. 177 final Map<String, String> environment = processBuilder.environment(); 178 environment.clear(); 179 for (final Map.Entry<Object, Object> entry : envProperties.entrySet()) { 180 environment.put(JSType.toString(entry.getKey()), JSType.toString(entry.getValue())); 181 } 182 } 183 184 // Start the process. 185 final Process process = processBuilder.start(); 186 final IOException exception[] = new IOException[2]; 187 188 // Collect output. 189 final StringBuilder outBuffer = new StringBuilder(); 190 final Thread outThread = new Thread(new Runnable() { 191 @Override 192 public void run() { 193 final char buffer[] = new char[1024]; 194 try (final InputStreamReader inputStream = new InputStreamReader(process.getInputStream())) { 195 for (int length; (length = inputStream.read(buffer, 0, buffer.length)) != -1; ) { 196 outBuffer.append(buffer, 0, length); 197 } 198 } catch (final IOException ex) { 199 exception[0] = ex; 200 } 201 } 202 }, "$EXEC output"); 203 204 // Collect errors. 205 final StringBuilder errBuffer = new StringBuilder(); 206 final Thread errThread = new Thread(new Runnable() { 207 @Override 208 public void run() { 209 final char buffer[] = new char[1024]; 210 try (final InputStreamReader inputStream = new InputStreamReader(process.getErrorStream())) { 211 for (int length; (length = inputStream.read(buffer, 0, buffer.length)) != -1; ) { 212 errBuffer.append(buffer, 0, length); 213 } 214 } catch (final IOException ex) { 215 exception[1] = ex; 216 } 217 } 218 }, "$EXEC error"); 219 220 // Start gathering output. 221 outThread.start(); 222 errThread.start(); 223 224 // If input is present, pass on to process. 225 if (!JSType.nullOrUndefined(input)) { 226 try (OutputStreamWriter outputStream = new OutputStreamWriter(process.getOutputStream())) { 227 final String in = JSType.toString(input); 228 outputStream.write(in, 0, in.length()); 229 } catch (final IOException ex) { 230 // Process was not expecting input. May be normal state of affairs. 231 } 232 } 233 234 // Wait for the process to complete. 235 final int exit = process.waitFor(); 236 outThread.join(); 237 errThread.join(); 238 239 final String out = outBuffer.toString(); 240 final String err = errBuffer.toString(); 241 242 // Set globals for secondary results. 243 global.set(OUT_NAME, out, 0); 244 global.set(ERR_NAME, err, 0); 245 global.set(EXIT_NAME, exit, 0); 246 247 // Propagate exception if present. 248 for (final IOException element : exception) { 249 if (element != null) { 250 throw element; 251 } 252 } 253 254 // if we got a non-zero exit code ("failure"), then we have to decide to throw error or not 255 if (exit != 0) { 256 // get the $EXEC function object from the global object 257 final Object exec = global.get(EXEC_NAME); 258 assert exec instanceof ScriptObject : EXEC_NAME + " is not a script object!"; 259 260 // Check if the user has set $EXEC.throwOnError property to true. If so, throw RangeError 261 // If that property is not set or set to false, then silently proceed with the rest. 262 if (JSType.toBoolean(((ScriptObject)exec).get(THROW_ON_ERROR_NAME))) { 263 throw rangeError("exec.returned.non.zero", ScriptRuntime.safeToString(exit)); 264 } 265 } 266 267 // Return the result from stdout. 268 return out; 269 } 270 271 private static MethodHandle findOwnMH(final String name, final Class<?> rtype, final Class<?>... types) { 272 return MH.findStatic(MethodHandles.lookup(), ScriptingFunctions.class, name, MH.type(rtype, types)); 273 } 274 275 /** 276 * Break a string into tokens, honoring quoted arguments and escaped spaces. 277 * 278 * @param str a {@link String} to tokenize. 279 * @return a {@link List} of {@link String}s representing the tokens that 280 * constitute the string. 281 * @throws IOException in case {@link StreamTokenizer#nextToken()} raises it. 282 */ 283 public static List<String> tokenizeString(final String str) throws IOException { 284 final StreamTokenizer tokenizer = new StreamTokenizer(new StringReader(str)); 285 tokenizer.resetSyntax(); 286 tokenizer.wordChars(0, 255); 287 tokenizer.whitespaceChars(0, ' '); 288 tokenizer.commentChar('#'); 289 tokenizer.quoteChar('"'); 290 tokenizer.quoteChar('\''); 291 final List<String> tokenList = new ArrayList<>(); 292 final StringBuilder toAppend = new StringBuilder(); 293 while (tokenizer.nextToken() != StreamTokenizer.TT_EOF) { 294 final String s = tokenizer.sval; 295 // The tokenizer understands about honoring quoted strings and recognizes 296 // them as one token that possibly contains multiple space-separated words. 297 // It does not recognize quoted spaces, though, and will split after the 298 // escaping \ character. This is handled here. 299 if (s.endsWith("\\")) { 300 // omit trailing \, append space instead 301 toAppend.append(s.substring(0, s.length() - 1)).append(' '); 302 } else { 303 tokenList.add(toAppend.append(s).toString()); 304 toAppend.setLength(0); 305 } 306 } 307 if (toAppend.length() != 0) { 308 tokenList.add(toAppend.toString()); 309 } 310 return tokenList; 311 } 312} 313