1 // File: CommandLineOptions.cs
3 // This is a re-usable component to be used when you
4 // need to parse command-line options/parameters.
6 // Separates command line parameters from command line options.
7 // Uses reflection to populate member variables the derived class with the values
10 // An option can start with "/", "-" or "--".
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
17 // An example to explain:
18 // csc /nologo /t:exe myfile.cs
26 // Please see a short description of the CommandLineOptions class
27 // at http://codeblast.com/~gert/dotnet/sells.html
29 // Gert Lombard (gert@codeblast.com)
30 // James Newkirk (jim@nunit.org)
35 using System
.Reflection
;
36 using System
.Collections
;
43 [AttributeUsage(AttributeTargets
.Field
)]
44 public class OptionAttribute
: Attribute
46 protected object optValue
;
47 protected string optName
;
48 protected string description
;
52 get { return optName; }
53 set { optName = value; }
58 get { return optValue; }
59 set { optValue = value; }
62 public string Description
64 get { return description; }
65 set { description = value; }
70 // The CommandLineOptions members
73 public abstract class CommandLineOptions
75 protected ArrayList parameters
;
76 private int optionCount
;
78 public CommandLineOptions(string[] args
)
80 optionCount
= Init(args
);
87 return ParameterCount
== 0 && optionCount
== 0;
91 public int Init(string[] args
)
95 while (n
< args
.Length
)
97 int pos
= IsOption(args
[n
]);
101 if (GetOption(args
, ref n
, pos
))
104 InvalidOption(args
[Math
.Min(n
, args
.Length
-1)]);
109 if (parameters
== null) parameters
= new ArrayList();
110 parameters
.Add(args
[n
]);
117 // An option starts with "/", "-" or "--":
118 protected virtual int IsOption(string opt
)
125 else if (opt
.Length
> 2)
127 c
= opt
.ToCharArray(0, 3);
128 if (c
[0] == '-' && c
[1] == '-' && IsOptionNameChar(c
[2])) return 2;
132 c
= opt
.ToCharArray(0, 2);
134 if ((c
[0] == '-' || c
[0] == '/') && IsOptionNameChar(c
[1])) return 1;
138 protected virtual bool IsOptionNameChar(char c
)
140 return Char
.IsLetterOrDigit(c
) || c
== '?';
143 protected abstract void InvalidOption(string name
);
145 protected virtual bool MatchShortName(FieldInfo field
, string name
)
147 object[] atts
= field
.GetCustomAttributes(typeof(OptionAttribute
), true);
148 foreach (OptionAttribute att
in atts
)
150 if (string.Compare(att
.Short
, name
, true) == 0) return true;
155 protected virtual FieldInfo
GetMemberField(string name
)
157 Type t
= this.GetType();
158 FieldInfo
[] fields
= t
.GetFields(BindingFlags
.Instance
|BindingFlags
.Public
);
159 foreach (FieldInfo field
in fields
)
161 if (string.Compare(field
.Name
, name
, true) == 0) return field
;
162 if (MatchShortName(field
, name
)) return field
;
167 protected virtual object GetOptionValue(FieldInfo field
)
169 object[] atts
= field
.GetCustomAttributes(typeof(OptionAttribute
), true);
172 OptionAttribute att
= (OptionAttribute
)atts
[0];
178 protected virtual bool GetOption(string[] args
, ref int index
, int pos
)
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
);
188 object value = GetOptionValue(field
);
191 if (field
.FieldType
== typeof(bool))
192 value = true; // default for bool values is true
193 else if(field
.FieldType
== typeof(string))
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;
202 value = cmdLineVal
!= null ? cmdLineVal
: args
[++index
];
204 field
.SetValue(this, Convert
.ChangeType(value, field
.FieldType
));
210 // Ignore exceptions like type conversion errors.
215 protected virtual void SplitOptionAndValue(ref string opt
, ref object val
)
217 // Look for ":" or "=" separator in the option:
218 int pos
= opt
.IndexOfAny( new char[] { ':', '=' }
);
221 val
= opt
.Substring(pos
+1);
222 opt
= opt
.Substring(0, pos
);
225 // Parameter accessor:
226 public string this[int index
]
230 if (parameters
!= null) return (string)parameters
[index
];
235 public ArrayList Parameters
237 get { return parameters; }
240 public int ParameterCount
244 return parameters
== null ? 0 : parameters
.Count
;
248 public virtual void Help()
250 Console
.WriteLine(GetHelpText());
253 public virtual string GetHelpText()
255 StringBuilder helpText
= new StringBuilder();
257 Type t
= this.GetType();
258 FieldInfo
[] fields
= t
.GetFields(BindingFlags
.Instance
|BindingFlags
.Public
);
259 foreach (FieldInfo field
in fields
)
261 object[] atts
= field
.GetCustomAttributes(typeof(OptionAttribute
), true);
264 OptionAttribute att
= (OptionAttribute
)atts
[0];
265 if (att
.Description
!= null)
268 if (att
.Value
== null)
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";
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
);
282 return helpText
.ToString();