/*
* $Id$
*
* Copyright (C) 2003-2015 JNode.org
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library 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 Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; If not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
package org.jnode.shell.bjorne;
import static org.jnode.shell.bjorne.BjorneInterpreter.REDIR_CLOBBER;
import static org.jnode.shell.bjorne.BjorneInterpreter.REDIR_DGREAT;
import static org.jnode.shell.bjorne.BjorneInterpreter.REDIR_DLESS;
import static org.jnode.shell.bjorne.BjorneInterpreter.REDIR_DLESSDASH;
import static org.jnode.shell.bjorne.BjorneInterpreter.REDIR_GREAT;
import static org.jnode.shell.bjorne.BjorneInterpreter.REDIR_GREATAND;
import static org.jnode.shell.bjorne.BjorneInterpreter.REDIR_LESS;
import static org.jnode.shell.bjorne.BjorneInterpreter.REDIR_LESSAND;
import static org.jnode.shell.bjorne.BjorneInterpreter.REDIR_LESSGREAT;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintStream;
import java.io.StringReader;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.TreeMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.jnode.shell.Command;
import org.jnode.shell.CommandLine;
import org.jnode.shell.CommandShell;
import org.jnode.shell.PathnamePattern;
import org.jnode.shell.ShellException;
import org.jnode.shell.ShellFailureException;
import org.jnode.shell.ShellSyntaxException;
import org.jnode.shell.io.CommandIO;
import org.jnode.shell.io.CommandIOHolder;
import org.jnode.shell.io.CommandInput;
import org.jnode.shell.io.CommandOutput;
/**
* This class holds the shell variable and stream state for a bjorne shell
* context. A parent context persists between calls to the shell's
* <code>interpret</code> method to hold the global shell variables. Others
* are created as required to hold the (umm) lexically scoped state for
* individual commands, pipelines, subshells and function calls.
*
* @author crawley@jnode.org
*/
public class BjorneContext {
private static final int NONE = 1;
private static final int HASH = 2;
private static final int DHASH = 3;
private static final int PERCENT = 4;
private static final int DPERCENT = 5;
private static final int MINUS = 6;
private static final int COLONMINUS = 7;
private static final int EQUALS = 8;
private static final int COLONEQUALS = 9;
private static final int PLUS = 10;
private static final int COLONPLUS = 11;
private static final int QUERY = 12;
private static final int COLONQUERY = 13;
private final BjorneInterpreter interpreter;
private Map<String, VariableSlot> variables;
private TreeMap<String, String> aliases;
private TreeMap<String, CommandNode> functions;
private String command = "";
private List<String> args = new ArrayList<String>();
private int lastReturnCode;
private int shellPid;
private int lastAsyncPid;
private boolean tildeExpansion = true;
private boolean globbing = true;
private String options = "";
private CommandIOHolder[] holders;
private List<CommandIOHolder[]> savedHolders;
private boolean echoExpansions;
private BjorneContext parent;
public BjorneContext(BjorneInterpreter interpreter, CommandIOHolder[] holders) {
this.interpreter = interpreter;
this.holders = holders;
this.variables = new HashMap<String, VariableSlot>();
this.aliases = new TreeMap<String, String>();
this.functions = new TreeMap<String, CommandNode>();
initVariables();
}
public BjorneContext(BjorneInterpreter interpreter) {
this(interpreter, defaultStreamHolders());
}
private static CommandIOHolder[] defaultStreamHolders() {
CommandIOHolder[] res = new CommandIOHolder[4];
res[Command.STD_IN] = new CommandIOHolder(CommandLine.DEFAULT_STDIN, false);
res[Command.STD_OUT] = new CommandIOHolder(CommandLine.DEFAULT_STDOUT, false);
res[Command.STD_ERR] = new CommandIOHolder(CommandLine.DEFAULT_STDERR, false);
res[Command.SHELL_ERR] = new CommandIOHolder(CommandLine.DEFAULT_STDERR, false);
return res;
}
private void initVariables() {
setVariable("PS1", "$ ");
setVariable("PS2", "> ");
setVariable("PS4", "+ ");
setVariable("IFS", " \t\n");
}
/**
* Create a copy of a context with the same initial variable bindings and
* streams. Stream ownership is not transferred.
*
* @param parent the context that gives us our initial state.
*/
public BjorneContext(BjorneContext parent) {
this.parent = parent;
this.interpreter = parent.interpreter;
this.holders = copyStreamHolders(parent.holders);
this.variables = copyVariables(parent.variables);
this.aliases = new TreeMap<String, String>(parent.aliases);
this.functions = new TreeMap<String, CommandNode>(parent.functions);
this.globbing = parent.globbing;
this.tildeExpansion = parent.tildeExpansion;
this.echoExpansions = parent.echoExpansions;
}
public boolean isTildeExpansion() {
return tildeExpansion;
}
public void setTildeExpansion(boolean tildeExpansion) {
this.tildeExpansion = tildeExpansion;
}
public boolean isGlobbing() {
return globbing;
}
public void setGlobbing(boolean globbing) {
this.globbing = globbing;
}
public boolean isNoClobber() {
return isVariableSet("NOCLOBBER");
}
void setEchoExpansions(boolean echoExpansions) {
this.echoExpansions = echoExpansions;
}
boolean isEchoExpansions() {
return this.echoExpansions;
}
final int getLastAsyncPid() {
return this.lastAsyncPid;
}
final int getLastReturnCode() {
return this.lastReturnCode;
}
final void setLastReturnCode(int rc) {
this.lastReturnCode = rc;
}
final int getShellPid() {
return this.shellPid;
}
final BjorneContext getParent() {
return this.parent;
}
/**
* Create a deep copy of some variable bindings
*/
private Map<String, VariableSlot> copyVariables(
Map<String, VariableSlot> variables) {
Map<String, VariableSlot> res = new HashMap<String, VariableSlot>(
variables.size());
for (Map.Entry<String, VariableSlot> entry : variables.entrySet()) {
res.put(entry.getKey(), new VariableSlot(entry.getValue()));
}
return res;
}
/**
* Create a copy of some stream holders without passing ownership.
*/
public static CommandIOHolder[] copyStreamHolders(CommandIOHolder[] holders) {
CommandIOHolder[] res = new CommandIOHolder[holders.length];
for (int i = 0; i < res.length; i++) {
res[i] = new CommandIOHolder(holders[i]);
}
return res;
}
CommandIOHolder[] getCopyOfHolders() {
return copyStreamHolders(holders);
}
CommandIOHolder[] getHolders() {
return holders;
}
void setArgs(String[] args) {
this.args = Arrays.asList(args.clone());
}
void setCommand(String command) {
this.command = command;
}
/**
* This method implements 'NAME=VALUE'. If variable NAME does not exist, it
* is created as an unexported shell variable.
*
* @param name the name of the variable to be set
* @param value a non-null value for the variable
*/
protected void setVariable(String name, String value) {
value.length(); // Check that the value is non-null.
VariableSlot var = variables.get(name);
if (var == null) {
variables.put(name, new VariableSlot(name, value, false));
} else if (!var.isReadOnly()) {
var.setValue(value);
}
}
/**
* Test if the variable is set in this context.
*
* @param name the name of the variable to be tested
* @return <code>true</code> if the variable is set.
*/
boolean isVariableSet(String name) {
return variables.get(name) != null;
}
/**
* Test if the variable is readonly in this context.
*
* @param name the name of the variable to be tested
* @return <code>true</code> if the variable is set.
*/
boolean isVariableReadonly(String name) {
VariableSlot var = variables.get(name);
return var != null && var.isReadOnly();
}
/**
* This method implements 'unset NAME'
*
* @param name the name of the variable to be unset
*/
void unsetVariable(String name) {
if (!variables.get(name).isReadOnly()) {
variables.remove(name);
}
}
/**
* This method implements 'readonly NAME'
*
* @param name the name of the variable to be marked as readonly
*/
void setVariableReadonly(String name, boolean readonly) {
VariableSlot var = variables.get(name);
if (var == null) {
var = new VariableSlot(name, "", false);
variables.put(name, var);
}
var.setReadOnly(readonly);
}
/**
* This method implements 'export NAME' or 'unexport NAME'.
*
* @param name the name of the variable to be exported / unexported
*/
void setVariableExported(String name, boolean exported) {
VariableSlot var = variables.get(name);
if (var == null) {
if (exported) {
variables.put(name, new VariableSlot(name, "", exported));
}
} else {
var.setExported(exported);
}
}
/**
* Get the complete alias map.
* @return the alias map
*/
TreeMap<String, String> getAliases() {
return aliases;
}
/**
* Lookup an alias
* @param aliasName the (possible) alias name
* @return the alias string or {@code null}
*/
String getAlias(String aliasName) {
return aliases.get(aliasName);
}
/**
* Define an alias
* @param aliasName the alias name
* @param alias the alias.
*/
void defineAlias(String aliasName, String alias) {
aliases.put(aliasName, alias);
}
/**
* Undefine an alias
* @param aliasName the alias name
*/
void undefineAlias(String aliasName) {
aliases.remove(aliasName);
}
/**
* Perform expand-and-split processing on an array of word tokens. The resulting
* wordTokens are assembled into a CommandLine.
*
* @param tokens the tokens to be expanded and split into words
* @return the command line
* @throws ShellException
*/
public CommandLine buildCommandLine(BjorneToken ... tokens) throws ShellException {
List<BjorneToken> wordTokens = expandAndSplit(tokens);
int nosWords = wordTokens.size();
if (nosWords == 0) {
return new CommandLine(null, null);
} else {
BjorneToken alias = wordTokens.remove(0);
BjorneToken[] args = wordTokens.toArray(new BjorneToken[nosWords - 1]);
return new CommandLine(alias, args, null);
}
}
/**
* Perform expand-and-split processing on a list of word tokens.
*
* @param tokens the tokens to be expanded and split into words
* @throws ShellException
*/
public List<BjorneToken> expandAndSplit(Iterable<BjorneToken> tokens)
throws ShellException {
List<BjorneToken> wordTokens = new LinkedList<BjorneToken>();
for (BjorneToken token : tokens) {
dollarBacktickSplit(token, wordTokens);
}
wordTokens = fileExpand(wordTokens);
wordTokens = dequote(wordTokens);
return wordTokens;
}
/**
* Perform full expand-and-split processing on an array of word tokens.
*
* @param tokens the tokens to be expanded and split into words
* @throws ShellException
*/
public List<BjorneToken> expandAndSplit(BjorneToken ... tokens) throws ShellException {
return expandAndSplit(Arrays.asList(tokens));
}
/**
* Do quote removal on a list of tokens
*
* @param wordTokens the tokens to be processed.
* @return the de-quoted tokens
*/
private List<BjorneToken> dequote(List<BjorneToken> wordTokens) {
List<BjorneToken> resTokens = new LinkedList<BjorneToken>();
for (BjorneToken token : wordTokens) {
resTokens.add(token.remake(dequote(token.getText())));
}
return resTokens;
}
/**
* Do quote removal on a String
*
* @param text the text to be processed.
* @return the de-quoted text
*/
static StringBuilder dequote(String text) {
int len = text.length();
StringBuilder sb = new StringBuilder(len);
int quote = 0;
for (int i = 0; i < len; i++) {
char ch = text.charAt(i);
switch (ch) {
case '"':
case '\'':
if (quote == 0) {
quote = ch;
} else if (quote == ch) {
quote = 0;
} else {
sb.append(ch);
}
break;
case '\\':
if (i + 1 < len) {
ch = text.charAt(++i);
}
sb.append(ch);
break;
default:
sb.append(ch);
break;
}
}
return sb;
}
/**
* Do dollar and backtick expansion on a token, split into words, retokenize and
* append the resulting tokens to 'wordTokens.
*
* @param token
* @param wordTokens
* @throws ShellException
*/
private void dollarBacktickSplit(BjorneToken token, List<BjorneToken> wordTokens)
throws ShellException {
String word = token.getText();
CharSequence expanded = dollarBacktickExpand(word);
if (expanded == word) {
splitAndAppend(token, wordTokens);
} else {
BjorneToken newToken = token.remake(expanded);
if (newToken != null) {
splitAndAppend(newToken, wordTokens);
}
}
}
private List<BjorneToken> fileExpand(List<BjorneToken> wordTokens) {
if (globbing || tildeExpansion) {
List<BjorneToken> globbedWordTokens = new LinkedList<BjorneToken>();
for (BjorneToken wordToken : wordTokens) {
if (tildeExpansion) {
wordToken = tildeExpand(wordToken);
}
if (globbing) {
globAppend(wordToken, globbedWordTokens);
} else {
globbedWordTokens.add(wordToken);
}
}
return globbedWordTokens;
} else {
return wordTokens;
}
}
private BjorneToken tildeExpand(BjorneToken wordToken) {
String word = wordToken.getText();
if (word.startsWith("~")) {
int slashPos = word.indexOf(File.separatorChar);
String name = (slashPos >= 0) ? word.substring(1, slashPos) : "";
// FIXME ... support "~username" when we have some kind of user info / management.
String home = (name.length() == 0) ? System.getProperty("user.home", "") : "";
if (home.length() == 0) {
return wordToken;
}
String expansion = (slashPos == -1) ?
home : (home + word.substring(slashPos));
return wordToken.remake(expansion);
} else {
return wordToken;
}
}
private void globAppend(BjorneToken wordToken, List<BjorneToken> globbedWordTokens) {
// Try to deal with the 'not-a-pattern' case quickly and cheaply.
String word = wordToken.getText();
if (!PathnamePattern.isPattern(word)) {
globbedWordTokens.add(wordToken);
return;
}
PathnamePattern pattern = PathnamePattern.compilePathPattern(word);
// Expand using the current directory as the base for relative path patterns.
LinkedList<String> paths = pattern.expand(new File("."));
// If it doesn't match anything, a pattern 'expands' to itself.
if (paths.isEmpty()) {
globbedWordTokens.add(wordToken);
} else {
for (String path : paths) {
globbedWordTokens.add(wordToken.remake(path));
}
}
}
/**
* Split a token into a series of word tokens, leaving quoting intact.
* The resulting tokens are appended to a supplied list.
*
* @param token the token to be split
* @param wordTokens the destination for the tokens.
* @throws ShellException
*/
void splitAndAppend(BjorneToken token, List<BjorneToken> wordTokens)
throws ShellException {
String text = token.getText();
StringBuilder sb = null;
int len = text.length();
int quote = 0;
for (int i = 0; i < len; i++) {
char ch = text.charAt(i);
switch (ch) {
case '"':
case '\'':
if (quote == 0) {
quote = ch;
} else if (quote == ch) {
quote = 0;
}
sb = accumulate(sb, ch);
break;
case ' ':
case '\t':
if (quote == 0) {
if (sb != null) {
wordTokens.add(token.remake(sb));
sb = null;
}
} else {
sb = accumulate(sb, ch);
}
break;
case '\\':
if (i + 1 < len) {
sb = accumulate(sb, ch);
ch = text.charAt(++i);
}
sb = accumulate(sb, ch);
break;
default:
sb = accumulate(sb, ch);
break;
}
}
if (sb != null) {
wordTokens.add(token.remake(sb));
}
}
protected StringBuffer runBacktickCommand(String commandLine) throws ShellException {
StringWriter capture = new StringWriter();
interpreter.interpret(interpreter.getShell(), new StringReader(commandLine), false, capture, false);
StringBuffer output = capture.getBuffer();
while (output.length() > 0 && output.charAt(output.length() - 1) == '\n') {
output.setLength(output.length() - 1);
}
return output;
}
private StringBuilder accumulate(StringBuilder sb, char ch) {
if (sb == null) {
sb = new StringBuilder();
}
sb.append(ch);
return sb;
}
/**
* Perform '$' expansion and backtick substitution. Any quotes and escapes must
* be preserved so that they escape globbing and tilde expansion.
*
* @param text the characters to be expanded
* @return the result of the expansion.
* @throws ShellException
*/
public CharSequence dollarBacktickExpand(CharSequence text) throws ShellException {
return dollarBacktickExpand(new CharIterator(text), -1);
}
private CharSequence dollarBacktickExpand(CharIterator ci, int terminator) throws ShellException {
StringBuilder sb = new StringBuilder(ci.nosRemaining());
int ch = ci.peekCh();
while (ch != -1 && ch != terminator) {
ci.nextCh();
switch (ch) {
case '"':
sb.append(doubleQuoteExpand(ci));
break;
case '\'':
sb.append(singleQuoteExpand(ci));
break;
case '`':
sb.append(backQuoteExpand(ci));
break;
case '$':
sb.append(dollarExpand(ci, (char) -1));
break;
case '\\':
sb.append((char) ch);
if ((ch = ci.nextCh()) != -1) {
sb.append((char) ch);
}
break;
default:
sb.append((char) ch);
break;
}
ch = ci.peekCh();
}
return sb;
}
private StringBuilder doubleQuoteExpand(CharIterator ci) throws ShellException {
StringBuilder sb = new StringBuilder(ci.nosRemaining());
sb.append('"');
int ch = ci.nextCh();
while (ch != -1) {
switch (ch) {
case '\'':
sb.append(singleQuoteExpand(ci));
break;
case '"':
sb.append('"');
return sb;
case '$':
sb.append(dollarExpand(ci, '"'));
break;
case '\\':
sb.append((char) ch);
if ((ch = ci.nextCh()) != -1) {
sb.append((char) ch);
}
break;
default:
sb.append((char) ch);
break;
}
ch = ci.nextCh();
}
throw new ShellSyntaxException("Unmatched \"'\" (double quote)");
}
private Object singleQuoteExpand(CharIterator ci) throws ShellSyntaxException {
StringBuilder sb = new StringBuilder(ci.nosRemaining());
sb.append('\'');
int ch = ci.nextCh();
while (ch != -1) {
switch (ch) {
case '\'':
sb.append('\'');
return sb;
case '\\':
sb.append((char) ch);
if ((ch = ci.nextCh()) != -1) {
sb.append((char) ch);
}
break;
default:
sb.append((char) ch);
break;
}
ch = ci.nextCh();
}
throw new ShellSyntaxException("Unmatched '\"' (single quote)");
}
private CharSequence backQuoteExpand(CharIterator ci) throws ShellException {
StringBuilder sb = new StringBuilder(ci.nosRemaining());
int ch = ci.nextCh();
while (ch != -1) {
switch (ch) {
case '"':
sb.append(doubleQuoteExpand(ci));
break;
case '\'':
sb.append(singleQuoteExpand(ci));
break;
case '`':
return runBacktickCommand(sb.toString());
case '$':
sb.append(dollarExpand(ci, '`'));
break;
case '\\':
sb.append((char) ch);
if ((ch = ci.nextCh()) != -1) {
sb.append((char) ch);
}
break;
default:
sb.append((char) ch);
break;
}
ch = ci.nextCh();
}
throw new ShellSyntaxException("Unmatched \"`\" (back quote)");
}
private CharSequence dollarExpand(CharIterator ci, char quote) throws ShellException {
int ch = ci.peekCh();
switch (ch) {
case -1:
return "$";
case '{':
ci.nextCh();
return dollarBraceExpand(ci);
case '(':
ci.nextCh();
return dollarParenExpand(ci);
case '$':
case '#':
case '@':
case '*':
case '?':
case '!':
case '-':
ci.nextCh();
return specialVariable(ch, quote == '"');
default:
String parameter = parseParameter(ci);
String value = (parameter.length() == 0) ? "$" : variable(parameter);
return value == null ? "" : value;
}
}
private CharSequence dollarBraceExpand(CharIterator ci) throws ShellException {
int ch = ci.peekCh();
if (ch == '#') {
ci.nextCh();
String parameter = parseParameter(ci);
if (ci.nextCh() != '}') {
throw new ShellSyntaxException("Unmatched \"{\"");
}
String value = variable(parameter);
return (value != null) ? Integer.toString(value.length()) : "0";
}
String parameter = parseParameter(ci);
ch = ci.nextCh();
int operator = NONE;
switch (ch) {
case -1:
throw new ShellSyntaxException("Unmatched \"{\"");
case '}':
break;
case '#':
if (ci.peekCh() == '#') {
ci.nextCh();
operator = DHASH;
} else {
operator = HASH;
}
break;
case '%':
if (ci.peekCh() == '%') {
ci.nextCh();
operator = DPERCENT;
} else {
operator = PERCENT;
}
break;
case ':':
switch (ci.peekCh()) {
case '=':
operator = COLONEQUALS;
break;
case '+':
operator = COLONPLUS;
break;
case '?':
operator = COLONQUERY;
break;
case '-':
operator = COLONMINUS;
break;
default:
throw new ShellSyntaxException("bad substitution operator");
}
ci.nextCh();
break;
case '=':
operator = EQUALS;
break;
case '?':
operator = QUERY;
break;
case '+':
operator = PLUS;
break;
case '-':
operator = MINUS;
break;
default:
throw new ShellSyntaxException("unrecognized substitution operator (\"" + (char) ch + "\")");
}
String value = variable(parameter);
if (operator == NONE) {
return (value != null) ? value : "";
}
String word = dollarBacktickExpand(ci, '}').toString();
if (ci.nextCh() != '}') {
throw new ShellSyntaxException("Unmatched \"{\"");
}
switch (operator) {
case MINUS:
return (value == null) ? word : value;
case COLONMINUS:
return (value == null || value.length() == 0) ? word : value;
case PLUS:
return (value == null) ? "" : word;
case COLONPLUS:
return (value == null || value.length() == 0) ? "" : word;
case QUERY:
if (value == null) {
String msg = word.length() > 0 ? word : (parameter + " is unset");
resolvePrintStream(getIO(Command.STD_ERR)).println(msg);
throw new BjorneControlException(BjorneInterpreter.BRANCH_EXIT, 1);
} else {
return value;
}
case COLONQUERY:
if (value == null || value.length() == 0) {
String msg = word.length() > 0 ? word : (parameter + " is unset or null");
resolvePrintStream(getIO(Command.STD_ERR)).println(msg);
throw new BjorneControlException(BjorneInterpreter.BRANCH_EXIT, 1);
} else {
return value;
}
case EQUALS:
if (value == null) {
setVariable(parameter, word);
return word;
} else {
return value;
}
case COLONEQUALS:
if (value == null || value.length() == 0) {
setVariable(parameter, word);
return word;
} else {
return value;
}
case HASH:
return patternEdit(value.toString(), word, false, false);
case DHASH:
return patternEdit(value.toString(), word, false, true);
case PERCENT:
return patternEdit(value.toString(), word, true, false);
case DPERCENT:
return patternEdit(value.toString(), word, true, true);
default:
throw new ShellFailureException("unimplemented substitution operator (" + operator + ")");
}
}
String parseParameter(CharIterator ci) throws ShellSyntaxException {
StringBuilder sb = new StringBuilder();
int ch = ci.peekCh();
while (Character.isLetterOrDigit((char) ch) || ch == '_') {
sb.append((char) ch);
ci.nextCh();
ch = ci.peekCh();
}
return sb.toString();
}
private String patternEdit(String value, String pattern, boolean suffix, boolean eager) {
if (value == null || value.length() == 0) {
return "";
}
if (pattern == null || pattern.length() == 0) {
return value;
}
// FIXME ... this does not work for a suffix == true, eager == false. We
// translate '*' to '.*?', but that won't give us the shortest suffix because
// Patterns inherently match from left to right.
int flags = (suffix ? PathnamePattern.ANCHOR_RIGHT : PathnamePattern.ANCHOR_LEFT) |
(eager ? PathnamePattern.EAGER : 0);
Pattern p = PathnamePattern.compilePosixShellPattern(pattern,
PathnamePattern.DEFAULT_FLAGS | flags);
Matcher m = p.matcher(value);
if (m.find()) {
if (suffix) {
return value.substring(0, m.start());
} else {
return value.substring(m.end());
}
} else {
return value;
}
}
@SuppressWarnings("unused")
private String reverse(String str) {
StringBuilder sb = new StringBuilder(str.length());
for (int i = str.length() - 1; i >= 0; i--) {
sb.append(str.charAt(i));
}
return sb.toString();
}
protected String variable(String parameter) throws ShellSyntaxException {
if (BjorneToken.isName(parameter)) {
VariableSlot var = variables.get(parameter);
return (var != null) ? var.getValue() : null;
} else {
try {
int argNo = Integer.parseInt(parameter);
return argVariable(argNo);
} catch (NumberFormatException ex) {
throw new ShellSyntaxException("bad substitution");
}
}
}
private String specialVariable(int ch, boolean inDoubleQuotes) {
switch (ch) {
case '$':
return Integer.toString(shellPid);
case '#':
return Integer.toString(args.size());
case '@':
return concatenateArgs(false, inDoubleQuotes);
case '*':
return concatenateArgs(true, inDoubleQuotes);
case '?':
return Integer.toString(lastReturnCode);
case '!':
return Integer.toString(lastAsyncPid);
case '-':
return options;
default:
return null;
}
}
private String concatenateArgs(boolean isStar, boolean inDoubleQuotes) {
StringBuilder sb = new StringBuilder();
for (String arg : args) {
if (sb.length() > 0) {
if (isStar || !inDoubleQuotes) {
sb.append(' ');
} else {
sb.append("\" \"");
}
}
sb.append(arg);
}
return sb.toString();
}
private String argVariable(int argNo) {
if (argNo == 0) {
return command;
} else if (argNo <= args.size()) {
return args.get(argNo - 1);
} else {
return null;
}
}
public boolean isSet(String name) {
return variables.get(name) != null;
}
private CharSequence dollarParenExpand(CharIterator ci) throws ShellException {
if (ci.peekCh() == '(') {
ci.nextCh();
return dollarParenParenExpand(ci);
} else {
String commandLine = dollarBacktickExpand(ci, ')').toString();
if (ci.nextCh() != ')') {
throw new ShellSyntaxException("Unmatched \"(\" (left parenthesis)");
}
return runBacktickCommand(commandLine);
}
}
private CharSequence dollarParenParenExpand(CharIterator ci) throws ShellException {
StringBuilder sb = new StringBuilder();
int nesting = 0;
boolean done = false;
do {
int ch = ci.peekCh();
switch (ch) {
case '(':
nesting++;
sb.append('(');
break;
case ')':
if (nesting > 0) {
nesting--;
sb.append(')');
} else if (ci.peekCh() == ')') {
ci.nextCh();
done = true;
} else {
sb.append(')');
}
break;
case -1:
throw new ShellSyntaxException("Unmatched \"((\" (double left parenthesis)");
default:
sb.append((char) ch);
}
ci.nextCh();
} while (!done);
CharSequence tmp = dollarBacktickExpand(new CharIterator(sb), '\000');
return new BjorneArithmeticEvaluator(this).evaluateExpression(tmp);
}
int execute(CommandLine command, CommandIO[] streams) throws ShellException {
if (isEchoExpansions()) {
StringBuilder sb = new StringBuilder();
sb.append(" + ").append(command.getCommandName());
for (String arg : command.getArguments()) {
sb.append(" ").append(interpreter.escapeWord(arg));
}
resolvePrintStream(streams[Command.STD_ERR]).println(sb);
}
Map<String, String> env = buildEnvFromExports();
lastReturnCode = interpreter.executeCommand(command, this, streams, null, env);
return lastReturnCode;
}
private Map<String, String> buildEnvFromExports() {
HashMap<String, String> map = new HashMap<String, String>(variables.size());
for (VariableSlot var : variables.values()) {
if (var.isExported()) {
map.put(var.getName(), var.getValue());
}
}
return Collections.unmodifiableMap(map);
}
PrintStream resolvePrintStream(CommandIO commandIOIF) {
return interpreter.resolvePrintStream(commandIOIF);
}
InputStream resolveInputStream(CommandIO stream) {
return interpreter.resolveInputStream(stream);
}
CommandIO getIO(int index) {
if (index < 0) {
throw new ShellFailureException("negative stream index");
} else if (index < holders.length) {
return holders[index].getIO();
} else {
return null;
}
}
void setIO(int index, CommandIO io, boolean mine) {
if (index < 0 || index >= holders.length) {
throw new ShellFailureException("bad stream index");
} else {
holders[index].setIO(io, mine);
}
}
void setIO(int index, CommandIOHolder holder) {
if (index < 0 || index >= holders.length) {
throw new ShellFailureException("bad stream index");
} else {
holders[index].setIO(holder);
}
}
void closeIOs() {
for (CommandIOHolder holder : holders) {
holder.close();
}
}
void flushIOs() {
for (CommandIOHolder holder : holders) {
holder.flush();
}
}
CommandIO[] getIOs() {
CommandIO[] io = new CommandIO[holders.length];
int i = 0;
for (CommandIOHolder holder : holders) {
io[i++] = (holder == null) ? null : holder.getIO();
}
return io;
}
void performAssignments(BjorneToken[] assignments) throws ShellException {
if (assignments != null) {
for (int i = 0; i < assignments.length; i++) {
String assignment = assignments[i].getText();
int pos = assignment.indexOf('=');
if (pos <= 0) {
throw new ShellFailureException("misplaced '=' in assignment");
}
String name = assignment.substring(0, pos);
String value = dollarBacktickExpand(assignment.substring(pos + 1)).toString();
this.setVariable(name, dequote(value).toString());
}
}
}
/**
* Evaluate the redirections for this command.
*
* @param redirects the redirection nodes to be evaluated
* @return an array representing the mapping of logical fds to
* input/outputStreamTuple streams for this command.
* @throws ShellException
*/
CommandIOHolder[] evaluateRedirections(RedirectionNode[] redirects) throws ShellException {
CommandIOHolder[] res = copyStreamHolders(holders);
evaluateRedirections(redirects, res);
return res;
}
/**
* Evaluate the redirections for this command, saving the context's existing IOs
*
* @param redirects the redirection nodes to be evaluated
* @throws ShellException
*/
void evaluateRedirectionsAndPushHolders(RedirectionNode[] redirects) throws ShellException {
if (savedHolders == null) {
savedHolders = new ArrayList<CommandIOHolder[]>(1);
}
savedHolders.add(holders);
holders = copyStreamHolders(holders);
evaluateRedirections(redirects, holders);
}
/**
* Evaluate the redirections for this command against a set of streams, saving the context's existing IOs.
*
* @param redirects the redirection nodes to be evaluated
* @param streams the base CommandIOs for the redirection calculation.
* @throws ShellException
*/
void evaluateRedirectionsAndPushHolders(RedirectionNode[] redirects, CommandIO[] streams)
throws ShellException {
if (savedHolders == null) {
savedHolders = new ArrayList<CommandIOHolder[]>(1);
}
savedHolders.add(holders);
holders = new CommandIOHolder[streams.length];
for (int i = 0; i < holders.length; i++) {
// Don't take ownership of the streams.
holders[i] = new CommandIOHolder(streams[i], false);
}
evaluateRedirections(redirects, holders);
}
/**
* Close the context's current IO, restoring the previous ones.
* @throws ShellException
*/
void popHolders() {
closeIOs();
holders = savedHolders.remove(savedHolders.size() - 1);
}
/**
* Evaluate the redirections for this command.
*
* @param redirects the redirection nodes to be evaluated
* @param holders the initial stream state which we will mutate
* @return the stream state after redirections
* @throws ShellException
*/
void evaluateRedirections(RedirectionNode[] redirects, CommandIOHolder[] holders)
throws ShellException {
if (redirects == null) {
return;
}
boolean ok = false;
try {
for (int i = 0; i < redirects.length; i++) {
RedirectionNode redir = redirects[i];
// Work out which fd to redirect ...
int fd;
BjorneToken io = redir.getIo();
if (io == null) {
switch (redir.getRedirectionType()) {
case REDIR_DLESS:
case REDIR_DLESSDASH:
case REDIR_LESS:
case REDIR_LESSAND:
case REDIR_LESSGREAT:
fd = 0;
break;
default:
fd = 1;
break;
}
} else {
try {
fd = Integer.parseInt(io.getText());
} catch (NumberFormatException ex) {
throw new ShellFailureException("Invalid &fd number");
}
}
// If necessary, grow the fd table.
if (fd >= holders.length) {
CommandIOHolder[] tmp = new CommandIOHolder[fd + 1];
System.arraycopy(holders, 0, tmp, 0, fd + 1);
holders = tmp;
}
CommandIOHolder stream;
CommandInput in;
CommandOutput out;
switch (redir.getRedirectionType()) {
case REDIR_DLESS:
case REDIR_DLESSDASH:
String here = redir.getHereDocument();
if (redir.isHereDocumentExpandable()) {
here = dollarBacktickExpand(here).toString();
}
in = new CommandInput(new StringReader(here));
stream = new CommandIOHolder(in, true);
break;
case REDIR_GREAT:
try {
File file = new File(redir.getArg().getText());
if (isNoClobber() && file.exists()) {
throw new ShellException("File already exists");
}
out = new CommandOutput(new FileOutputStream(file));
stream = new CommandIOHolder(out, true);
} catch (IOException ex) {
throw new ShellException("Cannot open output file", ex);
}
break;
case REDIR_CLOBBER:
case REDIR_DGREAT:
try {
FileOutputStream tmp = new FileOutputStream(redir.getArg().getText(),
redir.getRedirectionType() == REDIR_DGREAT);
stream = new CommandIOHolder(new CommandOutput(tmp), true);
} catch (IOException ex) {
throw new ShellException("Cannot open output file", ex);
}
break;
case REDIR_LESS:
try {
File file = new File(redir.getArg().getText());
in = new CommandInput(new FileInputStream(file));
stream = new CommandIOHolder(in, true);
} catch (IOException ex) {
throw new ShellException("Cannot open input file", ex);
}
break;
case REDIR_LESSAND:
try {
int fromFd = Integer.parseInt(redir.getArg().getText());
stream = (fromFd >= holders.length) ? null :
new CommandIOHolder(holders[fromFd]);
} catch (NumberFormatException ex) {
throw new ShellException("Invalid fd after <&");
}
break;
case REDIR_GREATAND:
try {
int fromFd = Integer.parseInt(redir.getArg().getText());
stream = (fromFd >= holders.length) ? null :
new CommandIOHolder(holders[fromFd]);
} catch (NumberFormatException ex) {
throw new ShellException("Invalid fd after >&");
}
break;
case REDIR_LESSGREAT:
throw new UnsupportedOperationException("<>");
default:
throw new ShellFailureException("unknown redirection type");
}
holders[fd] = stream;
}
ok = true;
} finally {
if (!ok) {
for (CommandIOHolder holder : holders) {
holder.close();
}
}
}
}
public boolean patternMatch(CharSequence text, CharSequence pat) {
int flags = PathnamePattern.EAGER | PathnamePattern.DEFAULT_FLAGS;
Pattern regex = PathnamePattern.compilePosixShellPattern(pat, flags);
return regex.matcher(text).matches();
}
public String[] getArgs() {
return args.toArray(new String[args.size()]);
}
public int nosArgs() {
return args.size();
}
public CommandShell getShell() {
return interpreter.getShell();
}
public String getName() {
return interpreter.getUniqueName();
}
public BjorneToken[] substituteAliases(BjorneToken[] words) throws ShellSyntaxException {
String alias = aliases.get(words[0].getText());
if (alias == null) {
return words;
}
List<BjorneToken> list = new LinkedList<BjorneToken>(Arrays.asList(words));
substituteAliases(list, 0, 0);
return list.toArray(new BjorneToken[list.size()]);
}
private void substituteAliases(List<BjorneToken> list, int pos, int depth) throws ShellSyntaxException {
if (depth > 10) {
throw new ShellFailureException("probable cycle detected in alias expansion");
}
String aliasName = list.get(pos).getText();
String alias = aliases.get(aliasName);
if (alias == null) {
return;
}
BjorneTokenizer tokens = new BjorneTokenizer(alias);
list.remove(pos);
int i = 0;
while (tokens.hasNext()) {
list.add(pos + i, tokens.next());
if (i == 0 && !aliasName.equals(list.get(pos + i).getText())) {
substituteAliases(list, pos + i, depth + 1);
}
i++;
}
if (alias.endsWith(" ") && pos + i < list.size()) {
substituteAliases(list, pos + i, depth + 1);
}
}
BjorneInterpreter getInterpreter() {
return interpreter;
}
public Collection<String> getVariableNames() {
return variables.keySet();
}
void defineFunction(BjorneToken name, CommandNode body) {
functions.put(name.getText(), body);
}
CommandNode getFunction(String name) {
return functions.get(name);
}
}