Question

I hope you guys can help me out.
I’m using C# .Net 4.0

I want validate file structure like

 
const string dataFileScr = @"
Start 0
{
    Next = 1
    Author = rk
    Date = 2011-03-10
/*  Description = simple */
}

PZ 11
{
IA_return()
}

GDC 7
{
    Message = 6
    Message = 7
        Message = 8
        Message = 8
    RepeatCount = 2
    ErrorMessage = 10
    ErrorMessage = 11
    onKey[5] = 6
    onKey[6] = 4
    onKey[9] = 11
}
";

So far I managed to build this regex pattern

 
const string patternFileScr = @"
^                           
((?:\[|\s)*                  

     (?<Section>[^\]\r\n]*)     
 (?:\])*                     
 (?:[\r\n]{0,}|\Z))         
(
    (?:\{)                  ### !! improve for .ini file, dont take { 
    (?:[\r\n]{0,}|\Z)           
        (                          # Begin capture groups (Key Value Pairs)
        (?!\}|\[)                    # Stop capture groups if a } is found; new section  

          (?:\s)*                     # Line with space
          (?<Key>[^=]*?)            # Any text before the =, matched few as possible
          (?:[\s]*=[\s]*)                     # Get the = now
          (?<Value>[^\r\n]*)        # Get everything that is not an Line Changes


         (?:[\r\n]{0,})
         )*                        # End Capture groups
    (?:[\r\n]{0,})
    (?:\})?
    (?:[\r\n\s]{0,}|\Z)
)*

                ";

and c#

  Dictionary <string, Dictionary<string, string>> DictDataFileScr
            = (from Match m in Regex.Matches(dataFileScr,
                                            patternFileScr,
                                            RegexOptions.IgnorePatternWhitespace | RegexOptions.Multiline)
               select new
               {
                   Section = m.Groups["Section"].Value,

                   kvps = (from cpKey in m.Groups["Key"].Captures.Cast().Select((a, i) => new { a.Value, i })
                           join cpValue in m.Groups["Value"].Captures.Cast().Select((b, i) => new { b.Value, i }) on cpKey.i equals cpValue.i
                           select new KeyValuePair(cpKey.Value, cpValue.Value)).OrderBy(_ => _.Key)
                           .ToDictionary(kvp => kvp.Key, kvp => kvp.Value)

               }).ToDictionary(itm => itm.Section, itm => itm.kvps);

It works for

 
const string dataFileScr = @"
Start 0
{
    Next = 1
    Author = rk
    Date = 2011-03-10
/*  Description = simple */
}

GDC 7
{
    Message = 6
    RepeatCount = 2
    ErrorMessage = 10
    onKey[5] = 6
    onKey[6] = 4
    onKey[9] = 11
}
";

in other words

 
Section1
{
key1=value1
key2=value2
}

Section2
{
key1=value1
key2=value2
}

, but

1. not for multiple keyname, i want group by key and output

DictDataFileScr["GDC 7"]["Message"] = "6|7|8|8"
DictDataFileScr["GDC 7"]["ErrorMessage"] = "10|11"

2. not work for .ini file like

....
[Section1]
key1 = value1
key2 = value2

[Section2]
key1 = value1
key2 = value2
...

3. dont see next section after

....
PZ 11
{
IA_return()
}
.....

Answer 1

Here is a complete rework of the regex in C#.

Assumptions : (tell me if one of them is false or all are false)

1. An INI file section can only have key/value pair lines in its body
2. In an non INI file section, function calls can’t have any parameters

Regex flags :
RegexOptions.IgnoreCase | RegexOptions.IgnorePatternWhitespace | RegexOptions.Compiled | RegexOptions.Singleline

---

Input test:

const string dataFileScr = @"
Start 0
{
    Next = 1
    Author = rk
    Date = 2011-03-10
/*  Description = simple */
}

PZ 11
{
IA_return()
}

GDC 7
{
    Message = 6
    Message = 7
        Message = 8
        Message = 8
    RepeatCount = 2
    ErrorMessage = 10
    ErrorMessage = 11
    onKey[5] = 6
    onKey[6] = 4
    onKey[9] = 11
}

[Section1]
key1 = value1
key2 = value2

[Section2]
key1 = value1
key2 = value2
";

Reworked regex:

const string patternFileScr = @"
(?<Section>                                                              (?# Start of a non ini file section)
  (?<SectionName>[\w ]+)\s*                                              (?# Capture section name)
     {                                                                   (?# Match but don't capture beginning of section)
        (?<SectionBody>                                                  (?# Capture section body. Section body can be empty)
         (?<SectionLine>\s*                                              (?# Capture zero or more line(s) in the section body)
         (?:                                                             (?# A line can be either a key/value pair, a comment or a function call)
            (?<KeyValuePair>(?<Key>[\w\[\]]+)\s*=\s*(?<Value>[\w-]*))    (?# Capture key/value pair. Key and value are sub-captured separately)
            |
            (?<Comment>/\*.+?\*/)                                        (?# Capture comment)
            |
            (?<FunctionCall>[\w]+\(\))                                   (?# Capture function call. A function can't have parameters though)
         )\s*                                                            (?# Match but don't capture white characters)
         )*                                                              (?# Zero or more line(s), previously mentionned in comments)
        )
     }                                                                   (?# Match but don't capture beginning of section)
)
|
(?<Section>                                                              (?# Start of an ini file section)
  \[(?<SectionName>[\w ]+)\]                                             (?# Capture section name)
  (?<SectionBody>                                                        (?# Capture section body. Section body can be empty)
     (?<SectionLine>                                                     (?# Capture zero or more line(s) in the section body. Only key/value pair allowed.)
        \s*(?<KeyValuePair>(?<Key>[\w\[\]]+)\s*=\s*(?<Value>[\w-]+))\s*  (?# Capture key/value pair. Key and value are sub-captured separately)
     )*                                                                  (?# Zero or more line(s), previously mentionned in comments)
  )
)
";

---

Discussion
The regex is build to match either non INI file sections (1) or INI file section (2).

(1) Non-INI file sections These sections are composed by a section name followed by a body enclosed by { and }.
The section name con contain either letters, digits or spaces.
The section body is composed by zero or more lines. A line can be either a key/value pair (key = value), a comment (/* Here is a comment */) or a function call with no parameters (my_function()).

(2) INI file sections
These sections are composed by a section name enclosed by [ and ] followed by zero or more key/value pairs. Each pair is on one line.