001/*
002 * Copyright (C) 2009-2017 the original author(s).
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package org.fusesource.jansi;
017
018import org.fusesource.jansi.internal.Kernel32;
019
020import static org.fusesource.jansi.internal.CLibrary.STDERR_FILENO;
021import static org.fusesource.jansi.internal.CLibrary.STDOUT_FILENO;
022import static org.fusesource.jansi.internal.CLibrary.isatty;
023
024import java.io.FilterOutputStream;
025import java.io.IOException;
026import java.io.OutputStream;
027import java.io.PrintStream;
028import java.io.UnsupportedEncodingException;
029import java.nio.charset.Charset;
030import java.util.Locale;
031
032/**
033 * Provides consistent access to an ANSI aware console PrintStream.
034 *
035 * @author <a href="http://hiramchirino.com">Hiram Chirino</a>
036 * @since 1.0
037 */
038public class AnsiConsole {
039
040    public static final PrintStream system_out = System.out;
041    public static final PrintStream out;
042
043    public static final PrintStream system_err = System.err;
044    public static final PrintStream err;
045
046    private static final boolean IS_WINDOWS = System.getProperty("os.name").toLowerCase(Locale.ENGLISH).contains("win");
047
048    private static final boolean IS_CYGWIN = IS_WINDOWS
049            && System.getenv("PWD") != null
050            && System.getenv("PWD").startsWith("/")
051            && !"cygwin".equals(System.getenv("TERM"));
052
053    private static final boolean IS_MINGW = IS_WINDOWS
054            && System.getenv("MSYSTEM") != null
055            && System.getenv("MSYSTEM").startsWith("MINGW");
056
057    static {
058        String charset = Charset.defaultCharset().name();
059        if (IS_WINDOWS && !IS_CYGWIN && !IS_MINGW) {
060            int codepage = Kernel32.GetConsoleOutputCP();
061            //http://docs.oracle.com/javase/6/docs/technotes/guides/intl/encoding.doc.html
062            if (Charset.isSupported("ms" + codepage)) {
063                charset = "ms" + codepage;
064            } else if (Charset.isSupported("cp" + codepage)) {
065                charset = "cp" + codepage;
066            }
067        }
068        try {
069            out = new PrintStream(wrapOutputStream(system_out), false, charset);
070            err = new PrintStream(wrapErrorOutputStream(system_err), false, charset);
071        } catch (UnsupportedEncodingException e) {
072            throw new RuntimeException(e);
073        }
074    }
075
076    private static int installed;
077
078    private AnsiConsole() {
079    }
080
081    public static OutputStream wrapOutputStream(final OutputStream stream) {
082        try {
083            return wrapOutputStream(stream, STDOUT_FILENO);
084        } catch (Throwable ignore) {
085            return wrapOutputStream(stream, 1);
086        }
087    }
088
089    public static OutputStream wrapErrorOutputStream(final OutputStream stream) {
090        try {
091            return wrapOutputStream(stream, STDERR_FILENO);
092        } catch (Throwable ignore) {
093            return wrapOutputStream(stream, 2);
094        }
095    }
096
097    public static OutputStream wrapOutputStream(final OutputStream stream, int fileno) {
098
099        // If the jansi.passthrough property is set, then don't interpret
100        // any of the ansi sequences.
101        if (Boolean.getBoolean("jansi.passthrough")) {
102            return stream;
103        }
104
105        // If the jansi.strip property is set, then we just strip the
106        // the ansi escapes.
107        if (Boolean.getBoolean("jansi.strip")) {
108            return new AnsiOutputStream(stream);
109        }
110
111        if (IS_WINDOWS && !IS_CYGWIN && !IS_MINGW) {
112
113            // On windows we know the console does not interpret ANSI codes..
114            try {
115                return new WindowsAnsiOutputStream(stream);
116            } catch (Throwable ignore) {
117                // this happens when JNA is not in the path.. or
118                // this happens when the stdout is being redirected to a file.
119            }
120
121            // Use the ANSIOutputStream to strip out the ANSI escape sequences.
122            return new AnsiOutputStream(stream);
123        }
124
125        // We must be on some Unix variant, including Cygwin or MSYS(2) on Windows...
126        try {
127            // If the jansi.force property is set, then we force to output
128            // the ansi escapes for piping it into ansi color aware commands (e.g. less -r)
129            boolean forceColored = Boolean.getBoolean("jansi.force");
130            // If we can detect that stdout is not a tty.. then setup
131            // to strip the ANSI sequences..
132            if (!forceColored && isatty(fileno) == 0) {
133                return new AnsiOutputStream(stream);
134            }
135        } catch (Throwable ignore) {
136            // These errors happen if the JNI lib is not available for your platform.
137            // But since we are on ANSI friendly platform, assume the user is on the console.
138        }
139
140        // By default we assume your Unix tty can handle ANSI codes.
141        // Just wrap it up so that when we get closed, we reset the
142        // attributes.
143        return new FilterOutputStream(stream) {
144            @Override
145            public void close() throws IOException {
146                write(AnsiOutputStream.RESET_CODE);
147                flush();
148                super.close();
149            }
150        };
151    }
152
153    /**
154     * If the standard out natively supports ANSI escape codes, then this just
155     * returns System.out, otherwise it will provide an ANSI aware PrintStream
156     * which strips out the ANSI escape sequences or which implement the escape
157     * sequences.
158     *
159     * @return a PrintStream which is ANSI aware.
160     */
161    public static PrintStream out() {
162        return out;
163    }
164
165    /**
166     * If the standard out natively supports ANSI escape codes, then this just
167     * returns System.err, otherwise it will provide an ANSI aware PrintStream
168     * which strips out the ANSI escape sequences or which implement the escape
169     * sequences.
170     *
171     * @return a PrintStream which is ANSI aware.
172     */
173    public static PrintStream err() {
174        return err;
175    }
176
177    /**
178     * Install Console.out to System.out.
179     */
180    synchronized static public void systemInstall() {
181        installed++;
182        if (installed == 1) {
183            System.setOut(out);
184            System.setErr(err);
185        }
186    }
187
188    /**
189     * undo a previous {@link #systemInstall()}.  If {@link #systemInstall()} was called
190     * multiple times, it {@link #systemUninstall()} must call the same number of times before
191     * it is actually uninstalled.
192     */
193    synchronized public static void systemUninstall() {
194        installed--;
195        if (installed == 0) {
196            System.setOut(system_out);
197            System.setErr(system_err);
198        }
199    }
200
201}