Question

I am creating a blog site, where i will be allowing user to enter code inside [Code] Code Content [/Code]

There will be multiple [Code] blocks like this in one blog post.

I want to find each [Code] block using Regex and then replace it with

<pre>command

Also i want to replace < and > inside pre tag to < >

Now i found useful code which can help me through that but i am confused with Regex, can someone help me with this.

    static string ProcessCodeBlocks(string value)
{
    StringBuilder result = new StringBuilder();

    Match m = Regex.Match(value, @"\[pre=(?<lang>[a-z]+)\](?<code>.*?)\[/pre\]");
    int index = 0;
    while( m.Success )
    {
        if( m.Index > index )
            result.Append(value, index, m.Index - index);

        result.AppendFormat("<pre class=\"{0}\">", m.Groups["lang"].Value);
        result.Append(ReplaceBreaks(m.Groups["code"].Value));
        result.Append("</pre>");

        index = m.Index + m.Length;
        m = m.NextMatch();
    }

    if( index < value.Length )
        result.Append(value, index, value.Length - index);

    return result.ToString();
}

Answer 1

..explanation from RegexBuddy:

\[pre=(?<lang>[a-z]+)\](?<code>.*?)\[/pre\]

Match the character “[” literally «\[»
Match the characters “pre=” literally «pre=»
Match the regular expression below and capture its match into backreference with name     “lang” «(?<lang>[a-z]+)»
   Match a single character in the range between “a” and “z” «[a-z]+»
      Between one and unlimited times, as many times as possible, giving back as needed     (greedy) «+»
Match the character “]” literally «\]»
Match the regular expression below and capture its match into backreference with name     “code” «(?<code>.*?)»
   Match any single character that is not a line break character «.*?»
      Between zero and unlimited times, as few times as possible, expanding as needed (lazy) «*?»
Match the character “[” literally «\[»
Match the characters “/pre” literally «/pre»
Match the character “]” literally «\]»

To make it work for [Code][/Code], you would change it to this:

\[code\](?<code>.*?)\[/code\]

..keeping in mind this will only work for single-line blocks. Also, there is only a code group.. there is no lang group anymore.. so remove that from the C#..