Regular expression to read multiple groups of text from a text file.

[rajeev4983]

I have an EDI file whose structure is given below. This file has multiple records, each record contains a header(e.g EDI.DD.00000000 01.20130809), then contents (i.e multiple paragraphs of text) and then footer (e.g End of Report/No EDI Activity). I have to read that entire file using regular expression using three groups.

I am using following regular expression to read the file.

(?<header>[A-Z]{3}.[A-Z]{2}.[0-9]{10}.[0-9]{8}) | (?<footer> \b(End\sof\sRep ort|No\sEDI\sAc tivity)\b) |

(?<content>(?<= \k<header>).*(? =\k<footer>))

That expression reads the "header" and "footer" in respective groups properly but didn't pick the contents between header and footer in "contents" group.

I have changed the font of header and footer in below file to help to understand the format. I am using asp.net 3.5 framework.

Thanks for your help in advance.

//------------------Start of EDI File---------------------//

EDI.DD.00000000 01.20130809

ORIGINATOR INFORMATION Company Name: UNITED HEALTHCAR Identification: 9024125001 Originating DFI: 002100002

RECEIVER INFORMATION Receiver Name: HEALTH & WELLNESS DFI Account Number: 000000000000000 1 Receiving DFI ID: 434343430 ID Number: Transaction Type: 22 Deposit

ORIGINATOR INFORMATION Company Name: BLUE CHOICE Identification: 9024125001

End of Report

EDI.DD.00065789 87.20130809

No EDI Activity

EDI.SV.00000005 55.20130809

ORIGINATOR INFORMATION Company Name: Univ of Florida Identification: A426004813 Originating DFI: 004200001

TRANSACTION INFORMATION
Entry Description: vndr pymnt Entry Class Code: CTX Service Class Code: ACH Entries Mixed

REMITTANCE ADVICE ACCOUNTS
RECEIVABLE OPEN ITEM REFERENCE
Seller's Invoice Number: 10016 Pmt Action Code: Amount Paid: $800.00 Amount of Invoice: Amount of Discount:

End of Report

//--------------------End of file------------------------//

[MichaelvdB]

Note: (?<contents>.*? ) -- This is a non-greedy match meaning the .* does not try to match the whole string. The RegexOptions.Si ngleline option treats the input to the Matches function as one long string instead of multiple lines.

Regex re = new Regex(
"(?<header>[A-Z]{3}.[A-Z]{2}.[0-9]{10}.[0-9]{8})" +
"(?<contents>.*?)" +
"(?<footer>(End of Report|No EDI Activity))",
RegexOptions.Singleline);

MatchCollection matches = re.Matches(fileData);

foreach(Match m in matches) {
   Console.WriteLine("Header: {0}, Body Length: {1}, Footer: {2}",
      m.Groups["header"].Value,
      m.Groups["contents"].Value.Length,
      m.Groups["footer"].Value);
}

Run results:

Header: EDI.DD.0000000001.20130809, Body Length: 356, Footer: End of Report
Header: EDI.DD.0006578987.20130809, Body Length: 4, Footer: No EDI Activity
Header: EDI.SV.0000000555.20130809, Body Length: 403, Footer: End of Report