util/ShellVariableDef.java

   1
   2 package org.de.metux.util;
   3
   4 // a simplicistic parser for shell style variable definitions
   5 // FIXME: has to be improved
   6
   7 public class ShellVariableDef
   8 {
   9     public String name;
  10     public String value;
  11
  12     public boolean getBoolean ()
  13     {
  14         if ((value!=null) && (value.equals("yes")))
  15             return true;
  16         else
  17             return false;
  18     }
  19
  20     public class XEmpty extends Exception
  21     {
  22         public XEmpty(String s) { super(s); }
  23     }
  24     public class XParseFailed extends Exception
  25     {
  26         public XParseFailed(String s) { super(s); }
  27     }
  28
  29     public int getInt()
  30     {
  31         try
  32         {
  33             return Integer.parseInt(value);
  34         }
  35         catch (NumberFormatException e)
  36         {
  37             System.err.println(
  38                 "ShellVariableDef::getInt() format error: "+
  39                 name+"'"+value+"'");
  40             throw e;
  41         }
  42     }
  43
  44     public int getInt(int def)
  45     {
  46         try
  47         {
  48             return Integer.parseInt(value);
  49         }
  50         catch (NumberFormatException e)
  51         {
  52             return def;
  53         }
  54     }
  55
  56     public ShellVariableDef(String line) throws XEmpty, XParseFailed
  57     {
  58         if (line==null)
  59             throw new XEmpty("null pointer assigned");
  60
  61         line = line.trim();
  62
  63         if (line.length()<1)
  64             throw new ShellVariableDef.XEmpty("empty string (1)");
  65
  66         // look for an # (comment)
  67         int comment_pos = line.indexOf('#');
  68
  69         // look for an equal sign
  70         int equal_pos;
  71         if ((equal_pos=line.indexOf("='"))>0)
  72         {
  73             if ((comment_pos>-1) && (comment_pos<equal_pos))
  74                 throw new ShellVariableDef.XParseFailed("# before =");
  75
  76             int fin_pos = line.indexOf('\'', equal_pos+2);
  77             if (fin_pos <= -1)
  78                 throw new ShellVariableDef.XParseFailed("missing closing \"'\"");
  79
  80             name  = line.substring(0,equal_pos).trim();
  81             value = line.substring(equal_pos+2,fin_pos);
  82         }
  83
  84         else if ((equal_pos=line.indexOf("="))>0)
  85         {
  86             if ((comment_pos>-1) && (comment_pos<equal_pos))
  87                 throw new ShellVariableDef.XParseFailed("# before =");
  88
  89             name  = line.substring(0,equal_pos).trim();
  90
  91             int fin_pos = line.indexOf(' ', equal_pos);
  92
  93             if (fin_pos>1)
  94                 value = line.substring(equal_pos+1,fin_pos);
  95             else
  96                 value = line.substring(equal_pos+1);
  97         }
  98
  99         else
 100         {
 101             // we have to test, whether the line is in fact empty
 102             if (comment_pos==0)
 103                 throw new ShellVariableDef.XEmpty("just comments (1)");
 104
 105             if ((comment_pos>0)&&(line.substring(0,comment_pos).trim().length()<1))
 106                 throw new ShellVariableDef.XEmpty("just comments (2)");
 107
 108             throw new ShellVariableDef.XParseFailed("missing =");
 109         }
 110
 111     }
 112 }