CODEWITHSUNDEEP
c#listfile-iofilter
Clodoaldo Neto
Clodoaldo Neto

Reputation: 125414

Filter files in a directory according to a date in the file name

I need to filter files in a directory based on a date in the file name.

The name has four groups of numbers:

9999.99999.201305021219.99999999.txt

When there is more than one file with the second group of numbers repeated I want to use the newer one based on the date on the third group of numbers (YYYYMMDDHHMM).

If there are these files in the directory:

1   1100.04037.201305090945.04542592.TXT
2   1100.04041.201305091108.04542707.TXT
3   1100.04041.201305091117.60563353.TXT
4   1100.04047.201305080942.04541666.TXT
5   1100.24084.201305021658.04539125.TXT
6   1100.24084.201305061731.04540560.TXT

I want those in the lines 2 and 5 to be discarded. This is how I managed to iterate over the directory files:

    public static void Main(string[] args)
    {
        string directory = @"\\some\net\path";
        string[] arquivos = Directory.GetFiles(directory, "1100.*.txt", SearchOption.TopDirectoryOnly);
        foreach (string arquivo in arquivos)
        {
            Console.WriteLine(arquivo.Substring(directory.Length + 1));
        }
        Console.ReadLine();
    }

Upvotes: 2

Views: 945

Answers (3)

Alexander
Alexander

Reputation: 4173

var ci = CultureInfo.InvariantCulture;

// first, parse your input files:
var parsed = 
from f in arquivos 
let c = Path.GetFileName(f).Split('.')
select new 
{ 
  Key = c[1], 
  Name = f, 
  Date = DateTime.ParseExact(c[2], "yyyyMMddHHmm", ci) 
};

// now, group by file id, and order by file date, 
// picking record by latest date:
var result = 
parsed.GroupBy(g => g.Key)
.Select(t => t.OrderByDescending(z => z.Date)
.Select(z => z.Name).First()).ToList();

Upvotes: 1

I4V
I4V

Reputation: 35363

var files = arquivos
           .Select(f => new{OrgName = f, Parts = new FileInfo(f).Name.Split('.')})
           .GroupBy(x=>x.Parts[1])
           .Select(g=>g.OrderByDescending(x=>x.Parts[2]).First().OrgName);

foreach (string arquivo in files)
{
    .....
}

Upvotes: 3

Jesse Carter
Jesse Carter

Reputation: 21167

Depending on how many files are in the directory I'd suggest using a Dictionary to hold your values as you iterate through the folder. You can use the 2nd group of numbers as the key and then check to see if the key is already present in the dictionary. If it is, you can perform whatever comparison fits in order to determine which one you keep.

Upvotes: 2

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