/*
* Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package jdk.nashorn.internal.runtime;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.StreamTokenizer;
import java.io.StringReader;
import java.lang.ProcessBuilder.Redirect;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import static jdk.nashorn.internal.runtime.CommandExecutor.RedirectType.*;
import static jdk.nashorn.internal.runtime.ECMAErrors.rangeError;
/**
* The CommandExecutor class provides support for Nashorn's $EXEC
* builtin function. CommandExecutor provides support for command parsing,
* I/O redirection, piping, completion timeouts, # comments, and simple
* environment variable management (cd, setenv, and unsetenv).
*/
class CommandExecutor {
// Size of byte buffers used for piping.
private static final int BUFFER_SIZE = 1024;
// Test to see if running on Windows.
private static final boolean IS_WINDOWS =
AccessController.doPrivileged((PrivilegedAction<Boolean>)() -> {
return System.getProperty("os.name").contains("Windows");
});
// Cygwin drive alias prefix.
private static final String CYGDRIVE = "/cygdrive/";
// User's home directory
private static final String HOME_DIRECTORY =
AccessController.doPrivileged((PrivilegedAction<String>)() -> {
return System.getProperty("user.home");
});
// Various types of standard redirects.
enum RedirectType {
NO_REDIRECT,
REDIRECT_INPUT,
REDIRECT_OUTPUT,
REDIRECT_OUTPUT_APPEND,
REDIRECT_ERROR,
REDIRECT_ERROR_APPEND,
REDIRECT_OUTPUT_ERROR_APPEND,
REDIRECT_ERROR_TO_OUTPUT
};
// Prefix strings to standard redirects.
private static final String[] redirectPrefixes = new String[] {
"<",
"0<",
">",
"1>",
">>",
"1>>",
"2>",
"2>>",
"&>",
"2>&1"
};
// Map from redirectPrefixes to RedirectType.
private static final RedirectType[] redirects = new RedirectType[] {
REDIRECT_INPUT,
REDIRECT_INPUT,
REDIRECT_OUTPUT,
REDIRECT_OUTPUT,
REDIRECT_OUTPUT_APPEND,
REDIRECT_OUTPUT_APPEND,
REDIRECT_ERROR,
REDIRECT_ERROR_APPEND,
REDIRECT_OUTPUT_ERROR_APPEND,
REDIRECT_ERROR_TO_OUTPUT
};
/**
* The RedirectInfo class handles checking the next token in a command
* to see if it contains a redirect. If the redirect file does not butt
* against the prefix, then the next token is consumed.
*/
private static class RedirectInfo {
// true if a redirect was encountered on the current command.
private boolean hasRedirects;
// Redirect.PIPE or an input redirect from the command line.
private Redirect inputRedirect;
// Redirect.PIPE or an output redirect from the command line.
private Redirect outputRedirect;
// Redirect.PIPE or an error redirect from the command line.
private Redirect errorRedirect;
// true if the error stream should be merged with output.
private boolean mergeError;
RedirectInfo() {
this.hasRedirects = false;
this.inputRedirect = Redirect.PIPE;
this.outputRedirect = Redirect.PIPE;
this.errorRedirect = Redirect.PIPE;
this.mergeError = false;
}
/**
* check - tests to see if the current token contains a redirect
* @param token current command line token
* @param iterator current command line iterator
* @param cwd current working directory
* @return true if token is consumed
*/
boolean check(String token, final Iterator<String> iterator, final String cwd) {
// Iterate through redirect prefixes to file a match.
for (int i = 0; i < redirectPrefixes.length; i++) {
final String prefix = redirectPrefixes[i];
// If a match is found.
if (token.startsWith(prefix)) {
// Indicate we have at least one redirect (efficiency.)
hasRedirects = true;
// Map prefix to RedirectType.
final RedirectType redirect = redirects[i];
// Strip prefix from token
token = token.substring(prefix.length());
// Get file from either current or next token.
File file = null;
if (redirect != REDIRECT_ERROR_TO_OUTPUT) {
// Nothing left of current token.
if (token.length() == 0) {
if (iterator.hasNext()) {
// Use next token.
token = iterator.next();
} else {
// Send to null device if not provided.
token = IS_WINDOWS ? "NUL:" : "/dev/null";
}
}
// Redirect file.
file = resolvePath(cwd, token).toFile();
}
// Define redirect based on prefix.
switch (redirect) {
case REDIRECT_INPUT:
inputRedirect = Redirect.from(file);
break;
case REDIRECT_OUTPUT:
outputRedirect = Redirect.to(file);
break;
case REDIRECT_OUTPUT_APPEND:
outputRedirect = Redirect.appendTo(file);
break;
case REDIRECT_ERROR:
errorRedirect = Redirect.to(file);
break;
case REDIRECT_ERROR_APPEND:
errorRedirect = Redirect.appendTo(file);
break;
case REDIRECT_OUTPUT_ERROR_APPEND:
outputRedirect = Redirect.to(file);
errorRedirect = Redirect.to(file);
mergeError = true;
break;
case REDIRECT_ERROR_TO_OUTPUT:
mergeError = true;
break;
default:
return false;
}
// Indicate token is consumed.
return true;
}
}
// No redirect found.
return false;
}
/**
* apply - apply the redirects to the current ProcessBuilder.
* @param pb current ProcessBuilder
*/
void apply(final ProcessBuilder pb) {
// Only if there was redirects (saves new structure in ProcessBuilder.)
if (hasRedirects) {
// If output and error are the same file then merge.
final File outputFile = outputRedirect.file();
final File errorFile = errorRedirect.file();
if (outputFile != null && outputFile.equals(errorFile)) {
mergeError = true;
}
// Apply redirects.
pb.redirectInput(inputRedirect);
pb.redirectOutput(outputRedirect);
pb.redirectError(errorRedirect);
pb.redirectErrorStream(mergeError);
}
}
}
/**
* The Piper class is responsible for copying from an InputStream to an
* OutputStream without blocking the current thread.
*/
private static class Piper implements java.lang.Runnable {
// Stream to copy from.
private final InputStream input;
// Stream to copy to.
private final OutputStream output;
private final Thread thread;
Piper(final InputStream input, final OutputStream output) {
this.input = input;
this.output = output;
this.thread = new Thread(this, "$EXEC Piper");
}
/**
* start - start the Piper in a new daemon thread
* @return this Piper
*/
Piper start() {
thread.setDaemon(true);
thread.start();
return this;
}
/**
* run - thread action
*/
@Override
public void run() {
try {
// Buffer for copying.
final byte[] b = new byte[BUFFER_SIZE];
// Read from the InputStream until EOF.
int read;
while (-1 < (read = input.read(b, 0, b.length))) {
// Write available date to OutputStream.
output.write(b, 0, read);
}
} catch (final Exception e) {
// Assume the worst.
throw new RuntimeException("Broken pipe", e);
} finally {
// Make sure the streams are closed.
try {
input.close();
} catch (final IOException e) {
// Don't care.
}
try {
output.close();
} catch (final IOException e) {
// Don't care.
}
}
}
public void join() throws InterruptedException {
thread.join();
}
// Exit thread.
}
// Process exit statuses.
static final int EXIT_SUCCESS = 0;
static final int EXIT_FAILURE = 1;
// Copy of environment variables used by all processes.
private Map<String, String> environment;
// Input string if provided on CommandExecutor call.
private String inputString;
// Output string if required from CommandExecutor call.
private String outputString;
// Error string if required from CommandExecutor call.
private String errorString;
// Last process exit code.
private int exitCode;
// Input stream if provided on CommandExecutor call.
private InputStream inputStream;
// Output stream if provided on CommandExecutor call.
private OutputStream outputStream;
// Error stream if provided on CommandExecutor call.
private OutputStream errorStream;
// Ordered collection of current or piped ProcessBuilders.
private List<ProcessBuilder> processBuilders = new ArrayList<>();
CommandExecutor() {
this.environment = new HashMap<>();
this.inputString = "";
this.outputString = "";
this.errorString = "";
this.exitCode = EXIT_SUCCESS;
this.inputStream = null;
this.outputStream = null;
this.errorStream = null;
this.processBuilders = new ArrayList<>();
}
/**
* envVarValue - return the value of the environment variable key, or
* deflt if not found.
* @param key name of environment variable
* @param deflt value to return if not found
* @return value of the environment variable
*/
private String envVarValue(final String key, final String deflt) {
return environment.getOrDefault(key, deflt);
}
/**
* envVarLongValue - return the value of the environment variable key as a
* long value.
* @param key name of environment variable
* @return long value of the environment variable
*/
private long envVarLongValue(final String key) {
try {
return Long.parseLong(envVarValue(key, "0"));
} catch (final NumberFormatException ex) {
return 0L;
}
}
/**
* envVarBooleanValue - return the value of the environment variable key as a
* boolean value. true if the value was non-zero, false otherwise.
* @param key name of environment variable
* @return boolean value of the environment variable
*/
private boolean envVarBooleanValue(final String key) {
return envVarLongValue(key) != 0;
}
/**
* stripQuotes - strip quotes from token if present. Quoted tokens kept
* quotes to prevent search for redirects.
* @param token token to strip
* @return stripped token
*/
private static String stripQuotes(String token) {
if ((token.startsWith("\"") && token.endsWith("\"")) ||
token.startsWith("\'") && token.endsWith("\'")) {
token = token.substring(1, token.length() - 1);
}
return token;
}
/**
* resolvePath - resolves a path against a current working directory.
* @param cwd current working directory
* @param fileName name of file or directory
* @return resolved Path to file
*/
private static Path resolvePath(final String cwd, final String fileName) {
return Paths.get(sanitizePath(cwd)).resolve(fileName).normalize();
}
/**
* builtIn - checks to see if the command is a builtin and performs
* appropriate action.
* @param cmd current command
* @param cwd current working directory
* @return true if was a builtin command
*/
private boolean builtIn(final List<String> cmd, final String cwd) {
switch (cmd.get(0)) {
// Set current working directory.
case "cd":
final boolean cygpath = IS_WINDOWS && cwd.startsWith(CYGDRIVE);
// If zero args then use home directory as cwd else use first arg.
final String newCWD = cmd.size() < 2 ? HOME_DIRECTORY : cmd.get(1);
// Normalize the cwd
final Path cwdPath = resolvePath(cwd, newCWD);
// Check if is a directory.
final File file = cwdPath.toFile();
if (!file.exists()) {
reportError("file.not.exist", file.toString());
return true;
} else if (!file.isDirectory()) {
reportError("not.directory", file.toString());
return true;
}
// Set PWD environment variable to be picked up as cwd.
// Make sure Cygwin paths look like Unix paths.
String scwd = cwdPath.toString();
if (cygpath && scwd.length() >= 2 &&
Character.isLetter(scwd.charAt(0)) && scwd.charAt(1) == ':') {
scwd = CYGDRIVE + Character.toLowerCase(scwd.charAt(0)) + "/" + scwd.substring(2);
}
environment.put("PWD", scwd);
return true;
// Set an environment variable.
case "setenv":
if (3 <= cmd.size()) {
final String key = cmd.get(1);
final String value = cmd.get(2);
environment.put(key, value);
}
return true;
// Unset an environment variable.
case "unsetenv":
if (2 <= cmd.size()) {
final String key = cmd.get(1);
environment.remove(key);
}
return true;
}
return false;
}
/**
* preprocessCommand - scan the command for redirects, and sanitize the
* executable path
* @param tokens command tokens
* @param cwd current working directory
* @param redirectInfo redirection information
* @return tokens remaining for actual command
*/
private List<String> preprocessCommand(final List<String> tokens,
final String cwd, final RedirectInfo redirectInfo) {
// Tokens remaining for actual command.
final List<String> command = new ArrayList<>();
// iterate through all tokens.
final Iterator<String> iterator = tokens.iterator();
while (iterator.hasNext()) {
final String token = iterator.next();
// Check if is a redirect.
if (redirectInfo.check(token, iterator, cwd)) {
// Don't add to the command.
continue;
}
// Strip quotes and add to command.
command.add(stripQuotes(token));
}
if (command.size() > 0) {
command.set(0, sanitizePath(command.get(0)));
}
return command;
}
/**
* Sanitize a path in case the underlying platform is Cygwin. In that case,
* convert from the {@code /cygdrive/x} drive specification to the usual
* Windows {@code X:} format.
*
* @param d a String representing a path
* @return a String representing the same path in a form that can be
* processed by the underlying platform
*/
private static String sanitizePath(final String d) {
if (!IS_WINDOWS || (IS_WINDOWS && !d.startsWith(CYGDRIVE))) {
return d;
}
final String pd = d.substring(CYGDRIVE.length());
if (pd.length() >= 2 && pd.charAt(1) == '/') {
// drive letter plus / -> convert /cygdrive/x/... to X:/...
return pd.charAt(0) + ":" + pd.substring(1);
} else if (pd.length() == 1) {
// just drive letter -> convert /cygdrive/x to X:
return pd.charAt(0) + ":";
}
// remaining case: /cygdrive/ -> can't convert
return d;
}
/**
* createProcessBuilder - create a ProcessBuilder for the command.
* @param command command tokens
* @param cwd current working directory
* @param redirectInfo redirect information
*/
private void createProcessBuilder(final List<String> command,
final String cwd, final RedirectInfo redirectInfo) {
// Create new ProcessBuilder.
final ProcessBuilder pb = new ProcessBuilder(command);
// Set current working directory.
pb.directory(new File(sanitizePath(cwd)));
// Map environment variables.
final Map<String, String> processEnvironment = pb.environment();
processEnvironment.clear();
processEnvironment.putAll(environment);
// Apply redirects.
redirectInfo.apply(pb);
// Add to current list of commands.
processBuilders.add(pb);
}
/**
* command - process the command
* @param tokens tokens of the command
* @param isPiped true if the output of this command should be piped to the next
*/
private void command(final List<String> tokens, final boolean isPiped) {
// Test to see if we should echo the command to output.
if (envVarBooleanValue("JJS_ECHO")) {
System.out.println(String.join(" ", tokens));
}
// Get the current working directory.
final String cwd = envVarValue("PWD", HOME_DIRECTORY);
// Preprocess the command for redirects.
final RedirectInfo redirectInfo = new RedirectInfo();
final List<String> command = preprocessCommand(tokens, cwd, redirectInfo);
// Skip if empty or a built in.
if (command.isEmpty() || builtIn(command, cwd)) {
return;
}
// Create ProcessBuilder with cwd and redirects set.
createProcessBuilder(command, cwd, redirectInfo);
// If piped, wait for the next command.
if (isPiped) {
return;
}
// Fetch first and last ProcessBuilder.
final ProcessBuilder firstProcessBuilder = processBuilders.get(0);
final ProcessBuilder lastProcessBuilder = processBuilders.get(processBuilders.size() - 1);
// Determine which streams have not be redirected from pipes.
boolean inputIsPipe = firstProcessBuilder.redirectInput() == Redirect.PIPE;
boolean outputIsPipe = lastProcessBuilder.redirectOutput() == Redirect.PIPE;
boolean errorIsPipe = lastProcessBuilder.redirectError() == Redirect.PIPE;
final boolean inheritIO = envVarBooleanValue("JJS_INHERIT_IO");
// If not redirected and inputStream is current processes' input.
if (inputIsPipe && (inheritIO || inputStream == System.in)) {
// Inherit current processes' input.
firstProcessBuilder.redirectInput(Redirect.INHERIT);
inputIsPipe = false;
}
// If not redirected and outputStream is current processes' output.
if (outputIsPipe && (inheritIO || outputStream == System.out)) {
// Inherit current processes' output.
lastProcessBuilder.redirectOutput(Redirect.INHERIT);
outputIsPipe = false;
}
// If not redirected and errorStream is current processes' error.
if (errorIsPipe && (inheritIO || errorStream == System.err)) {
// Inherit current processes' error.
lastProcessBuilder.redirectError(Redirect.INHERIT);
errorIsPipe = false;
}
// Start the processes.
final List<Process> processes = new ArrayList<>();
for (final ProcessBuilder pb : processBuilders) {
try {
processes.add(pb.start());
} catch (final IOException ex) {
reportError("unknown.command", String.join(" ", pb.command()));
return;
}
}
// Clear processBuilders for next command.
processBuilders.clear();
// Get first and last process.
final Process firstProcess = processes.get(0);
final Process lastProcess = processes.get(processes.size() - 1);
// Prepare for string based i/o if no redirection or provided streams.
ByteArrayOutputStream byteOutputStream = null;
ByteArrayOutputStream byteErrorStream = null;
final List<Piper> piperThreads = new ArrayList<>();
// If input is not redirected.
if (inputIsPipe) {
// If inputStream other than System.in is provided.
if (inputStream != null) {
// Pipe inputStream to first process output stream.
piperThreads.add(new Piper(inputStream, firstProcess.getOutputStream()).start());
} else {
// Otherwise assume an input string has been provided.
piperThreads.add(new Piper(new ByteArrayInputStream(inputString.getBytes()), firstProcess.getOutputStream()).start());
}
}
// If output is not redirected.
if (outputIsPipe) {
// If outputStream other than System.out is provided.
if (outputStream != null ) {
// Pipe outputStream from last process input stream.
piperThreads.add(new Piper(lastProcess.getInputStream(), outputStream).start());
} else {
// Otherwise assume an output string needs to be prepared.
byteOutputStream = new ByteArrayOutputStream(BUFFER_SIZE);
piperThreads.add(new Piper(lastProcess.getInputStream(), byteOutputStream).start());
}
}
// If error is not redirected.
if (errorIsPipe) {
// If errorStream other than System.err is provided.
if (errorStream != null) {
piperThreads.add(new Piper(lastProcess.getErrorStream(), errorStream).start());
} else {
// Otherwise assume an error string needs to be prepared.
byteErrorStream = new ByteArrayOutputStream(BUFFER_SIZE);
piperThreads.add(new Piper(lastProcess.getErrorStream(), byteErrorStream).start());
}
}
// Pipe commands in between.
for (int i = 0, n = processes.size() - 1; i < n; i++) {
final Process prev = processes.get(i);
final Process next = processes.get(i + 1);
piperThreads.add(new Piper(prev.getInputStream(), next.getOutputStream()).start());
}
// Wind up processes.
try {
// Get the user specified timeout.
final long timeout = envVarLongValue("JJS_TIMEOUT");
// If user specified timeout (milliseconds.)
if (timeout != 0) {
// Wait for last process, with timeout.
if (lastProcess.waitFor(timeout, TimeUnit.MILLISECONDS)) {
// Get exit code of last process.
exitCode = lastProcess.exitValue();
} else {
reportError("timeout", Long.toString(timeout));
}
} else {
// Wait for last process and get exit code.
exitCode = lastProcess.waitFor();
}
// Wait for all piper threads to terminate
for (final Piper piper : piperThreads) {
piper.join();
}
// Accumulate the output and error streams.
outputString += byteOutputStream != null ? byteOutputStream.toString() : "";
errorString += byteErrorStream != null ? byteErrorStream.toString() : "";
} catch (final InterruptedException ex) {
// Kill any living processes.
processes.stream().forEach(p -> {
if (p.isAlive()) {
p.destroy();
}
// Get the first error code.
exitCode = exitCode == 0 ? p.exitValue() : exitCode;
});
}
// If we got a non-zero exit code then possibly throw an exception.
if (exitCode != 0 && envVarBooleanValue("JJS_THROW_ON_EXIT")) {
throw rangeError("exec.returned.non.zero", ScriptRuntime.safeToString(exitCode));
}
}
/**
* createTokenizer - build up StreamTokenizer for the command script
* @param script command script to parsed
* @return StreamTokenizer for command script
*/
private static StreamTokenizer createTokenizer(final String script) {
final StreamTokenizer tokenizer = new StreamTokenizer(new StringReader(script));
tokenizer.resetSyntax();
// Default all characters to word.
tokenizer.wordChars(0, 255);
// Spaces and special characters are white spaces.
tokenizer.whitespaceChars(0, ' ');
// Ignore # comments.
tokenizer.commentChar('#');
// Handle double and single quote strings.
tokenizer.quoteChar('"');
tokenizer.quoteChar('\'');
// Need to recognize the end of a command.
tokenizer.eolIsSignificant(true);
// Command separator.
tokenizer.ordinaryChar(';');
// Pipe separator.
tokenizer.ordinaryChar('|');
return tokenizer;
}
/**
* process - process a command string
* @param script command script to parsed
*/
void process(final String script) {
// Build up StreamTokenizer for the command script.
final StreamTokenizer tokenizer = createTokenizer(script);
// Prepare to accumulate command tokens.
final List<String> command = new ArrayList<>();
// Prepare to acumulate partial tokens joined with "\ ".
final StringBuilder sb = new StringBuilder();
try {
// Fetch next token until end of script.
while (tokenizer.nextToken() != StreamTokenizer.TT_EOF) {
// Next word token.
String token = tokenizer.sval;
// If special token.
if (token == null) {
// Flush any partial token.
if (sb.length() != 0) {
command.add(sb.append(token).toString());
sb.setLength(0);
}
// Process a completed command.
// Will be either ';' (command end) or '|' (pipe), true if '|'.
command(command, tokenizer.ttype == '|');
if (exitCode != EXIT_SUCCESS) {
return;
}
// Start with a new set of tokens.
command.clear();
} else if (token.endsWith("\\")) {
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