mcs/nunit20/util/CommandLineOptions.cs

   1 // File: CommandLineOptions.cs
   2 //
   3 // This is a re-usable component to be used when you
   4 // need to parse command-line options/parameters.
   5 //
   6 // Separates command line parameters from command line options.
   7 // Uses reflection to populate member variables the derived class with the values
   8 // of the options.
   9 //
  10 // An option can start with "/", "-" or "--".
  11 //
  12 // I define 3 types of "options":
  13 //   1. Boolean options (yes/no values), e.g: /r to recurse
  14 //   2. Value options, e.g: /loglevel=3
  15 //   2. Parameters: standalone strings like file names
  16 //
  17 // An example to explain:
  18 //   csc /nologo /t:exe myfile.cs
  19 //       |       |      |
  20 //       |       |      + parameter
  21 //       |       |
  22 //       |       + value option
  23 //       |
  24 //       + boolean option
  25 //
  26 // Please see a short description of the CommandLineOptions class
  27 // at http://codeblast.com/~gert/dotnet/sells.html
  28 //
  29 // Gert Lombard (gert@codeblast.com)
  30 // James Newkirk (jim@nunit.org)
  31
  32 namespace Codeblast
  33 {
  34         using System;
  35         using System.Reflection;
  36         using System.Collections;
  37         using System.Text;
  38
  39         //
  40         // The Attributes
  41         //
  42
  43         [AttributeUsage(AttributeTargets.Field)]
  44         public class OptionAttribute : Attribute
  45         {
  46                 protected object optValue;
  47                 protected string optName;
  48                 protected string description;
  49
  50                 public string Short
  51                 {
  52                         get { return optName; }
  53                         set { optName = value; }
  54                 }
  55
  56                 public object Value
  57                 {
  58                         get { return optValue; }
  59                         set { optValue = value; }
  60                 }
  61
  62                 public string Description
  63                 {
  64                         get { return description; }
  65                         set { description = value; }
  66                 }
  67         }
  68
  69         //
  70         // The CommandLineOptions members
  71         //
  72
  73         public abstract class CommandLineOptions
  74         {
  75                 protected ArrayList parameters;
  76                 private int optionCount;
  77
  78                 public CommandLineOptions(string[] args)
  79                 {
  80                         optionCount = Init(args);
  81                 }
  82
  83                 public bool NoArgs
  84                 {
  85                         get
  86                         {
  87                                 return ParameterCount == 0 && optionCount == 0;
  88                         }
  89                 }
  90
  91                 public int Init(string[] args)
  92                 {
  93                         int count = 0;
  94                         int n = 0;
  95                         while (n < args.Length)
  96                         {
  97                                 int pos = IsOption(args[n]);
  98                                 if (pos > 0)
  99                                 {
 100                                         // It's an option:
 101                                         if (GetOption(args, ref n, pos))
 102                                                 count++;
 103                                         else
 104                                                 InvalidOption(args[Math.Min(n, args.Length-1)]);
 105                                 }
 106                                 else
 107                                 {
 108                                         // It's a parameter:
 109                                         if (parameters == null) parameters = new ArrayList();
 110                                         parameters.Add(args[n]);
 111                                 }
 112                                 n++;
 113                         }
 114                         return count;
 115                 }
 116
 117                 // An option starts with "/", "-" or "--":
 118                 protected virtual int IsOption(string opt)
 119                 {
 120                         char[] c = null;
 121                         if (opt.Length < 2)
 122                         {
 123                                 return 0;
 124                         }
 125                         else if (opt.Length > 2)
 126                         {
 127                                 c = opt.ToCharArray(0, 3);
 128                                 if (c[0] == '-' && c[1] == '-' && IsOptionNameChar(c[2])) return 2;
 129                         }
 130                         else
 131                         {
 132                                 c = opt.ToCharArray(0, 2);
 133                         }
 134                         if ((c[0] == '-' || c[0] == '/') && IsOptionNameChar(c[1])) return 1;
 135                         return 0;
 136                 }
 137
 138                 protected virtual bool IsOptionNameChar(char c)
 139                 {
 140                         return Char.IsLetterOrDigit(c) || c == '?';
 141                 }
 142
 143                 protected abstract void InvalidOption(string name);
 144
 145                 protected virtual bool MatchShortName(FieldInfo field, string name)
 146                 {
 147                         object[] atts = field.GetCustomAttributes(typeof(OptionAttribute), true);
 148                         foreach (OptionAttribute att in atts)
 149                         {
 150                                 if (string.Compare(att.Short, name, true) == 0) return true;
 151                         }
 152                         return false;
 153                 }
 154
 155                 protected virtual FieldInfo GetMemberField(string name)
 156                 {
 157                         Type t = this.GetType();
 158                         FieldInfo[] fields = t.GetFields(BindingFlags.Instance|BindingFlags.Public);
 159                         foreach (FieldInfo field in fields)
 160                         {
 161                                 if (string.Compare(field.Name, name, true) == 0) return field;
 162                                 if (MatchShortName(field, name)) return field;
 163                         }
 164                         return null;
 165                 }
 166
 167                 protected virtual object GetOptionValue(FieldInfo field)
 168                 {
 169                         object[] atts = field.GetCustomAttributes(typeof(OptionAttribute), true);
 170                         if (atts.Length > 0)
 171                         {
 172                                 OptionAttribute att = (OptionAttribute)atts[0];
 173                                 return att.Value;
 174                         }
 175                         return null;
 176                 }
 177
 178                 protected virtual bool GetOption(string[] args, ref int index, int pos)
 179                 {
 180                         try
 181                         {
 182                                 object cmdLineVal = null;
 183                                 string opt = args[index].Substring(pos, args[index].Length-pos);
 184                                 SplitOptionAndValue(ref opt, ref cmdLineVal);
 185                                 FieldInfo field = GetMemberField(opt);
 186                                 if (field != null)
 187                                 {
 188                                         object value = GetOptionValue(field);
 189                                         if (value == null)
 190                                         {
 191                                                 if (field.FieldType == typeof(bool))
 192                                                         value = true; // default for bool values is true
 193                                                 else if(field.FieldType == typeof(string))
 194                                                 {
 195                                                         value = cmdLineVal != null ? cmdLineVal : args[++index];
 196                                                         field.SetValue(this, Convert.ChangeType(value, field.FieldType));
 197                                                         string stringValue = (string)value;
 198                                                         if(stringValue == null || stringValue.Length == 0) return false;
 199                                                         return true;
 200                                                 }
 201                                                 else
 202                                                         value = cmdLineVal != null ? cmdLineVal : args[++index];
 203                                         }
 204                                         field.SetValue(this, Convert.ChangeType(value, field.FieldType));
 205                                         return true;
 206                                 }
 207                         }
 208                         catch (Exception)
 209                         {
 210                                 // Ignore exceptions like type conversion errors.
 211                         }
 212                         return false;
 213                 }
 214
 215                 protected virtual void SplitOptionAndValue(ref string opt, ref object val)
 216                 {
 217                         // Look for ":" or "=" separator in the option:
 218                         int pos = opt.IndexOfAny( new char[] { ':', '=' } );
 219                         if (pos < 1) return;
 220
 221                         val = opt.Substring(pos+1);
 222                         opt = opt.Substring(0, pos);
 223                 }
 224
 225                 // Parameter accessor:
 226                 public string this[int index]
 227                 {
 228                         get
 229                         {
 230                                 if (parameters != null) return (string)parameters[index];
 231                                 return null;
 232                         }
 233                 }
 234
 235                 public ArrayList Parameters
 236                 {
 237                         get { return parameters; }
 238                 }
 239
 240                 public int ParameterCount
 241                 {
 242                         get
 243                         {
 244                                 return parameters == null ? 0 : parameters.Count;
 245                         }
 246                 }
 247
 248                 public virtual void Help()
 249                 {
 250                         Console.WriteLine(GetHelpText());
 251                 }
 252
 253                 public virtual string GetHelpText()
 254                 {
 255                         StringBuilder helpText = new StringBuilder();
 256
 257                         Type t = this.GetType();
 258                         FieldInfo[] fields = t.GetFields(BindingFlags.Instance|BindingFlags.Public);
 259                         foreach (FieldInfo field in fields)
 260                         {
 261                                 object[] atts = field.GetCustomAttributes(typeof(OptionAttribute), true);
 262                                 if (atts.Length > 0)
 263                                 {
 264                                         OptionAttribute att = (OptionAttribute)atts[0];
 265                                         if (att.Description != null)
 266                                         {
 267                                                 string valType = "";
 268                                                 if (att.Value == null)
 269                                                 {
 270                                                         if (field.FieldType == typeof(float)) valType = "=FLOAT";
 271                                                         else if (field.FieldType == typeof(string)) valType = "=STR";
 272                                                         else if (field.FieldType != typeof(bool)) valType = "=X";
 273                                                 }
 274
 275                                                 helpText.AppendFormat("/{0,-20}{1}", field.Name+valType, att.Description);
 276                                                 if (att.Short != null)
 277                                                         helpText.AppendFormat(" (Short format: /{0}{1})", att.Short, valType);
 278                                                 helpText.Append( Environment.NewLine );
 279                                         }
 280                                 }
 281                         }
 282                         return helpText.ToString();
 283                 }
 284         }
 285 }