001    /*
002     * Copyright (C) 2012 eXo Platform SAS.
003     *
004     * This is free software; you can redistribute it and/or modify it
005     * under the terms of the GNU Lesser General Public License as
006     * published by the Free Software Foundation; either version 2.1 of
007     * the License, or (at your option) any later version.
008     *
009     * This software is distributed in the hope that it will be useful,
010     * but WITHOUT ANY WARRANTY; without even the implied warranty of
011     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
012     * Lesser General Public License for more details.
013     *
014     * You should have received a copy of the GNU Lesser General Public
015     * License along with this software; if not, write to the Free
016     * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
017     * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
018     */
019    package org.crsh.ssh.term;
020    
021    import org.apache.sshd.common.PtyMode;
022    import org.apache.sshd.server.Environment;
023    
024    import java.nio.charset.Charset;
025    import java.util.logging.Level;
026    import java.util.logging.Logger;
027    import java.util.regex.Matcher;
028    import java.util.regex.Pattern;
029    
030    public class SSHContext {
031    
032      /** . */
033      static final Pattern LC_TYPE_PATTERN = Pattern.compile("(?:\\p{Alpha}{2}_\\p{Alpha}{2}\\.)?([^@]+)(?:@.+)?");
034    
035      /**
036       * Parse the <code>LC_CTYPE</code> format or return null.
037       *
038       * @param value the value to parse
039       * @return the corresponding charset
040       */
041      public static Charset parseEncoding(String value) {
042        Matcher matcher = LC_TYPE_PATTERN.matcher(value);
043        if (matcher.matches()) {
044          String encoding = matcher.group(1);
045          try {
046            return Charset.forName(encoding);
047          }
048          catch (Exception e) {
049            log.log(Level.FINE, "Could not find charset " + encoding + " for LC_TYPE " + value, e);
050            return null;
051          }
052        } else {
053          log.log(Level.FINE, "Could not parse LC_TYPE " + value);
054        }
055        return null;
056      }
057    
058      /** . */
059      private static final Logger log = Logger.getLogger(SSHContext.class.getName());
060    
061      /** . */
062      public final int verase;
063    
064      /** . */
065      private final Environment env;
066    
067      /** . */
068      public final Charset encoding;
069    
070      public SSHContext(Environment env) {
071        if (env == null) {
072          throw new NullPointerException("No null env");
073        }
074    
075        //
076        Integer verase = env.getPtyModes().get(PtyMode.VERASE);
077        String LC_CTYPE = env.getEnv().get("LC_CTYPE");
078        Charset encoding;
079        if (LC_CTYPE != null) {
080          encoding = parseEncoding(LC_CTYPE);
081        } else {
082          encoding = null;
083        }
084    
085        //
086        this.env = env;
087        this.verase = verase != null ? verase : -1;
088        this.encoding = encoding;
089      }
090    
091      public int getWidth() {
092        String s = env.getEnv().get(Environment.ENV_COLUMNS);
093        int width = -1;
094        if (s != null) {
095          try {
096            width = Integer.parseInt(s);
097          }
098          catch (NumberFormatException e) {
099            log.log(Level.WARNING, "Could not parse ssh term width " + s);
100          }
101        }
102        return width;
103      }
104    
105      public int getHeight() {
106        String s = env.getEnv().get(Environment.ENV_LINES);
107        int height = -1;
108        if (s != null) {
109          try {
110            height = Integer.parseInt(s);
111          }
112          catch (NumberFormatException e) {
113            log.log(Level.WARNING, "Could not parse ssh term height " + s);
114          }
115        }
116        return height;
117      }
118    
119      public String getProperty(String key)
120      {
121        return env.getEnv().get(key);
122      }
123    }