parsing text file using linq

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i am working parsing textfile using LINQ but got struc on it,its going outof range exception

C#

string[] lines = File.ReadAllLines(input);
           var t1 = lines
               .Where(l => !l.StartsWith("#"))
               .Select(l => l.Split(' '))
               .Select(items => String.Format("{0}{1}{2}",
                   items[1].PadRight(32),
                   //items[1].PadRight(16)
                   items[2].PadRight(32),
                   items[3].PadRight(32)));
           var t2 = t1
               .Select(l => l.ToUpper());
           foreach (var t in t2)
               Console.WriteLine(t);

and file is about 200 to 500 lines and i want to extract specific information so i need to split that information to different structure so how to do it this..

Posted 29-Sep-12 9:05am

saniaali

Updated 29-Sep-12 9:24am

Zoltán Zörgő

v2

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Comments

Zoltán Zörgő 29-Sep-12 15:30pm

How exactly a row looks like and how you want to transform it?

saniaali 29-Sep-12 15:34pm

data is in this format
#comments start with this
input = 12
output = 4
pin class direction no
io 1 up 0
io 3 rught 1
cb 6 up 2
io 1 up 0

ect ...
so i need to extrct its pin information

Zoltán Zörgő 29-Sep-12 16:17pm

the etc... part is also interesting: after the input, output and table header there is only the table data in the file, or can be something else also? Comments can begin at any position in the row? Is the table of fixed structure in every file?

Greysontyrus 10-Oct-12 5:08am

Could we have a few rows (or the whole) of the input file please.
Whenever I see items[#] where # is hard coded I always shudder. The message says that there is a line that has less than 4 elements in a 'item'
You can confirm this by testing the file with your code but replacing the t1 linq to:
var t1 = lines
.Where(l => !l.StartsWith("#"))
.Where(l => l.Split(' ').Length < 4);
.Select(l => "'" + l.Replace(" ", "' '") + "'");
the Console.WriteLine(t); with then print any rows that causes an error in quotes so you can see each line and item as the lamba see it. You may find that a row is missing some ' 's so the .Split(' ') is failing to find 4 seperate elements

saniaali 29-Sep-12 16:36pm

yes comments can be in any place and more interesting is that there would be also space on others information in this format as well i need to find number of inputs ,output,other pins, there type,position ,rotation details..

Zoltán Zörgő 29-Sep-12 17:19pm

Well, without a proper format specification it would be impossible. Even for us :) But as we can not see any of those files, and we don't know what file this could be, we will only be able to guide you - but that is the purpose of this site.
So:
1) try to find, or figure out the most general format of the file
2) figure out how could you identify the interesting part or the uninteresting part, so you can separate these
3) Use regular expression to cleanup interesting part from comments
4) Use split or regular expression to parse the interesting rows
...oh, and by the way try to use the "reply" feature so that one can see that you replied to a comment.
Good luck

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Kolkata .NET · Accepted Answer · 2013-03-08T04:19:00

Solution 1

I think better go for regex if possible rather than a linq. after its more of string/characters than data/tables/lists. so why not use something text oriented solution?

Posted 8-Mar-13 4:19am

Kolkata .NET

Andreas Gieriet · Accepted Answer · 2013-03-09T11:03:00

You need to parse a file, so, the starting point is not LINQ (this is implementation detail), but rather defining the grammar of the file to the needed detail level to allow implememting a good-enough parser.

The grammar in your case looks to me somethin like:
( {...} = 0-n repetitions, [...] = optional, a | b = a or b, '...' = literal text)

file     : { line } .
line     : { ws } [ input | output | pin | data ] rest .
rest     : [ comment ] EOL .
comment  : { ws } '#' { NOT_EOL } .
ws       : SPACE_NOT_EOL .
input    : 'input' { ws } '=' { ws } number .
output   : 'output' { sw } '=' { ws } number .
pin      : 'pin' ws { ws } 'class' ws { ws } 'direction' ws { ws } 'no' .
data     : word ws { ws } number ws { ws } word ws { ws } number .
number   : DIGIT { DIGIT } .
word     : WORDCHAR { WORDCHAR } .

Implementing:

C#

// 1:   input|output|pin|data...
// 2-4: class,direction,no if pin
// 2-4: number, dir, number if data...
Regex scan = new Regex(
              @"^\s*(?:(\w+)\s*(?:=\s*\w+|(\w+)\s+(\w+)\s+(\w+)))?\s*(?:[#].*)?$",
              RegexOptions.Multiline);

var lines = scan.Matches(File.ReadAllText(@"..\..\data.txt"))
                .Cast<Match>()
                .Where(m=>m.Groups[1].Success)
foreach (var m in lines)
{
    switch (m.Groups[1].Value)
    {
        case "input": case "output": case "pin": // ignored
            break;
        default:
            Console.WriteLine("{0,-16} {1,4} {2,-6} {3,4}",
                              m.Groups[1].Value,
                              m.Groups[2].Value,
                              m.Groups[3].Value,
                              m.Groups[4].Value);
            break;
    }
}

With input file

# Header
input = 12
output = 4
# Data
pin class direction no     # Data Title
io    1      up        0
io    3      rught     1
cb    6      up        2
io    1      up        0
# End of data

Results in

io                  1 up        0
io                  3 rught     1
cb                  6 up        2
io                  1 up        0

Cheers
Andi