Question

I have an application that reads information from a text file and then categorizes them and puts them onto a Database. For one category, I need to check the line that comes right after the current line and look for a certain keyword?

How do i get to read this line? This should happen when the streamreader has the current line already open….

I’m using c# on VS2010.

Edit:

All of the code below is in a while (!sReader.EndOfStream) loop

 string line = sReader.ReadLine(); //Note: this is used way above and lots of things are done before we come to this loop

 for (int i = 0; i < filter_length; i++)
 {
       if (searchpattern_queries[i].IsMatch(line) == true)
       {
               logmessagtype = selected_queries[i];

               //*Here i need to add a if condition to check if the type is "RESTARTS" and i need to get the next line to do more classification. I need to get that line only to classify the current one. So, I'd want it to be open independently *

               hit = 1;
               if (logmessagtype == "AL-UNDEF")
               {
                   string alid = AlarmID_Search(line);
                   string query = "SELECT Severity from Alarms WHERE ALID like '" +alid +"'";
                   OleDbCommand cmdo = new OleDbCommand(query, conn);
                   OleDbDataReader reader;
                   reader = cmdo.ExecuteReader();
                   while (reader.Read())
                   {
                        if (reader.GetString(0).ToString() == null)
                        { }
                        else
                        {
                             string severity = reader.GetString(0).ToString();
                             if (severity == "1")
                                 //Keeps going on.....

Also, the .log files that are opened might go upto 50 Mb types… ! Which is why i dont really prefer reading all lines and keeping track!

Answer 1

Simply use

 string[] lines = File.ReadAllLines(filename);

and process the file with a for (int i = 0; i < lines.Length; i ++) loop.

For a big file, simply cache the ‘previous line’ or do an out-of-band ReadLine().