Question

I have a log file that I want to parse and load into a database. I’m struggling with the best way to go about parsing it.

The log file is in the format Category: Information

Case Number: CASE01  
User ID: JOSM  
Software: Microsoft Word  
Date Started: 21-01-2010  
Date Ended: 22-01-2010  

Thing is, there’s other bits and pieces thrown into the log file that mean the information isn’t always present on the same line. I also only want the information, not the category.

So far, I’ve tried stick it all into an array separated by \r\n, but I have to know the index of the information I want in order to consistently retrieve it, and that changes. I’ve also tried feeding it through StreamReader and saying

if (line.Contains("Case Number"))
{
    tbReport.AppendText("Case Number: " + line.Remove(0, 13) + "\r\n");
}

Which gets me the information I want, but makes it very hard to do anything with.

I feel I’m better off going down the array path, but I could do with some guidance on how to search the array for the the category, and then parse the information.

Once I can parse it accurately, adding it into a database should be fairly straight forward. As it’s my first time attempting this, I’d be interested in any tips or guidance as to the best way to go about this though.

Thanks.

Answer 1

This will give you a collection with all key/value pairs.

List<KeyValuePair> items = new List<KeyValuePair>();

var line = reader.ReadLine();
while (line != null)
{
    int pos = line.IndexOf(':');
    items.Add(new KeyValuePair(line.Substring(0, pos), line.Substring(pos+1));

    line = reader.ReadLine();
}

If you have a log class which contains all possible names as properties, you can use reflection instead:

class LogEntry
{
    public string CaseNumber { get; set; }
    public string User { get; set; }
    public string Software{ get; set; }
    public string DateStarted { get; set; }
    public string DateEnded { get; set; }
}

List<LogEntry> items = new List<LogEntry>();

var line = reader.ReadLine();
var currentEntry = new LogEntry();
while (line != null)
{
    if (line == "") //empty line = new log entry. Change to your delimiter.
    {
         items.Add(currentEntry);
         currentEntry = new LogEntry();
    }

    int pos = line.IndexOf(':');
    var name = line.Substring(0, pos).Replace(" ", string.Empty);
    var value = line.Substring(pos+1);

    var pi = entry.GetType().GetProperty(name);
    pi.SetValue(entry, value, null);


    line = reader.ReadLine();
}

Note that I’ve not tested the code (just written it directly in here). You have to add error checking and such. The last alternative is not very performant as it is, but should do OK.