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      1 /*
      2  * [The "BSD licence"]
      3  * Copyright (c) 2010 Ben Gruver
      4  * All rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  * 3. The name of the author may not be used to endorse or promote products
     15  *    derived from this software without specific prior written permission.
     16  *
     17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     25  * INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 package org.jf.util;
     29 
     30 import java.io.BufferedReader;
     31 import java.io.InputStreamReader;
     32 import java.util.regex.Matcher;
     33 import java.util.regex.Pattern;
     34 
     35 public class ConsoleUtil {
     36     /**
     37      * Attempt to find the width of the console. If it can't get the width, return a default of 80
     38      * @return The current console width
     39      */
     40     public static int getConsoleWidth() {
     41         if (System.getProperty("os.name").toLowerCase().contains("windows")) {
     42             try {
     43                 return attemptMode();
     44             } catch (Exception ex) {
     45             }
     46         } else {
     47             try {
     48                 return attemptStty();
     49             } catch (Exception ex) {
     50             }
     51         }
     52 
     53         return 80;
     54     }
     55 
     56     private static int attemptStty() {
     57         String output = attemptCommand(new String[]{"sh", "-c", "stty size < /dev/tty"});
     58         if (output == null) {
     59             return 80;
     60         }
     61 
     62         String[] vals = output.split(" ");
     63         if (vals.length < 2) {
     64             return 80;
     65         }
     66         return Integer.parseInt(vals[1]);
     67     }
     68 
     69     private static int attemptMode() {
     70         String output = attemptCommand(new String[]{"mode", "con"});
     71         if (output == null) {
     72             return 80;
     73         }
     74 
     75         Pattern pattern = Pattern.compile("Columns:[ \t]*(\\d+)");
     76         Matcher m = pattern.matcher(output);
     77         if (!m.find()) {
     78             return 80;
     79         }
     80 
     81         return Integer.parseInt(m.group(1));
     82     }
     83 
     84     private static String attemptCommand(String[] command) {
     85         StringBuffer buffer = null;
     86 
     87         try {
     88 
     89             Process p = Runtime.getRuntime().exec(command);
     90             BufferedReader reader = new BufferedReader(new InputStreamReader(p.getInputStream()));
     91 
     92             String line;
     93 
     94             while ((line = reader.readLine()) != null) {
     95                 if (buffer == null) {
     96                     buffer = new StringBuffer();
     97                 }
     98 
     99                 buffer.append(line);
    100             }
    101 
    102             if (buffer != null) {
    103                 return buffer.toString();
    104             }
    105             return null;
    106         } catch (Exception ex) {
    107             return null;
    108         }
    109     }
    110 }
    111