how to search for a string within a specific range of characters within a file name?

Question

How to search for a string within a specific range of characters within a file name by DirectoryInfo class?

I only need to select files that have "inscriz" in the character range 22 to 29

This is my code:

Public Sub SpostaFile(sourceDirectory As String, ByVal destDirectory As String)
    Try
        Dim from_date As DateTime = DateTime.Now.AddHours(-24)
        Dim to_date As DateTime = DateTime.Now.AddHours(+24)
        Try
            Dim folder As New DirectoryInfo(sourceDirectory)
            Dim pdfList = folder.EnumerateFiles("*.PDF").Where(Function(fi) fi.CreationTime >= from_date AndAlso fi.CreationTime <= to_date)
            Dim xlsList = folder.EnumerateFiles("*.XLS").Where(Function(fi) fi.CreationTime >= from_date AndAlso fi.CreationTime <= to_date)
            Dim xlsxList = folder.EnumerateFiles("*.XLSX").Where(Function(fi) fi.CreationTime >= from_date AndAlso fi.CreationTime <= to_date)
            Dim csvList = folder.EnumerateFiles("*.csv").Where(Function(fi) fi.CreationTime >= from_date AndAlso fi.CreationTime <= to_date)
            ' Copy pdf files.
            For Each file In pdfList
                file.CopyTo(Path.Combine(destDirectory, file.Name))
            Next
            ' Copy XLS files.
            For Each file In xlsList
                file.CopyTo(Path.Combine(destDirectory, file.Name))
            Next
            ' Copy XLSX files.
            For Each file In xlsxList
                file.CopyTo(Path.Combine(destDirectory, file.Name))
            Next
            ' Copy CSV files.
            For Each file In csvList
                file.CopyTo(Path.Combine(destDirectory, file.Name))
            Next
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try
    Catch ex As Exception
        MessageBox.Show(ex.Message)
    End Try
End Sub

Answer 1

Convert this:

Dim pdfList = folder.EnumerateFiles("*.PDF").Where(Function(fi) fi.CreationTime >= from_date AndAlso fi.CreationTime <= to_date)

to this:

Dim pdfList = folder.EnumerateFiles("*.PDF").
    Where(Function(fi) fi.CreationTime >= from_date AndAlso fi.CreationTime <= to_date AndAlso 
          fi.Name.Length >= 29 AndAlso fi.Name.Substring(22,7) = "inscriz" )

and do the same for the other file types.

I'll add a note that the question text says to search in the range between character 22 and 29, which is a 7 characters long, for set of text that is also seven characters. In that case, we can do a simple equality comparison. If the range were longer, we would use .Contains() instead.

---

I might also be tempted to do this, to avoid repetition, but there's a good argument to be made this is overkill, too:

Public Sub SpostaFile(sourceDirectory As String, ByVal destDirectory As String)
    Dim from_date As DateTime = DateTime.Now.AddHours(-24)
    Dim to_date As DateTime = DateTime.Now.AddHours(+24)
    Dim folder As New DirectoryInfo(sourceDirectory)

    Dim cp As Action(Of String) = 
    Sub(fileType) 
        Dim files = folder.EnumerateFiles(fileType).
            Where(Function(fi) fi.CreationTime >= from_date AndAlso fi.CreationTime <= to_date AndAlso 
                fi.Name.Length >= 29 AndAlso fi.Name.Substring(22,7) = "inscriz" )

        For Each file In xlsList
            file.CopyTo(Path.Combine(destDirectory, file.Name))
        Next
    End Sub

    Try
        cp("*.PDF")
        cp("*.XLS")
        cp("*.XLSX")
        cp("*.csv")
    Catch ex As Exception
        MessageBox.Show(ex.Message)
    End Try
End Sub

Answer 2

Use Substring, and simplify code with a reusable predicate to reduce maintenance

Public Sub SpostaFile(sourceDirectory As String, ByVal destDirectory As String)
    Try
        Dim from_date As DateTime = DateTime.Now.AddHours(-24)
        Dim to_date As DateTime = DateTime.Now.AddHours(+24)
        Dim searchString = "inscriz"
        Dim folder As New DirectoryInfo(sourceDirectory)
        Dim fileSearchPredicate As Func(Of FileInfo, Boolean) =
            Function(fi)
                Return fi.CreationTime >= from_date AndAlso fi.CreationTime <= to_date _
                AndAlso fi.Name.Length >= 29 AndAlso fi.Name.Substring(21, 8).Contains(searchString)
            End Function
        Dim pdfList = folder.EnumerateFiles("*.PDF").Where(fileSearchPredicate)
        Dim xlsList = folder.EnumerateFiles("*.XLS").Where(fileSearchPredicate)
        Dim xlsxList = folder.EnumerateFiles("*.XLSX").Where(fileSearchPredicate)
        Dim csvList = folder.EnumerateFiles("*.csv").Where(fileSearchPredicate)
        For Each file In pdfList ' Copy pdf files.
            file.CopyTo(Path.Combine(destDirectory, file.Name))
        Next
        For Each file In xlsList ' Copy XLS files.
            file.CopyTo(Path.Combine(destDirectory, file.Name))
        Next
        For Each file In xlsxList ' Copy XLSX files.
            file.CopyTo(Path.Combine(destDirectory, file.Name))
        Next
        For Each file In csvList ' Copy CSV files.
            file.CopyTo(Path.Combine(destDirectory, file.Name))
        Next
    Catch ex As Exception
        MessageBox.Show(ex.Message)
    End Try
End Sub

Answer 3

A Regex variant:

Dim R as new Regex("^.{21}inscriz")
Dim pdfList = folder.EnumerateFiles("*.PDF").Where(Function(fi) 
    fi.CreationTime >= fromDate AndAlso fi.CreationTime <= to_date AndAlso
    R.Match(fi.Name).Success)

Answer 4

Why not include this condition in the file filter?

Dim pdfList = folder.EnumerateFiles("??????????????????????inscriz*.PDF") .Where(
    Function(fi) fi.CreationTime >= from_date AndAlso fi.CreationTime <= to_date)

By creating a Sub for the repetitive part, you can make the code more readable

Public Sub SpostaFile(sourceDirectory As String, ByVal destDirectory As String)
    Try
        Dim folder As New DirectoryInfo(sourceDirectory)

        Dim from_date As DateTime = DateTime.Now.AddHours(-24)
        Dim to_date As DateTime = DateTime.Now.AddHours(+24)
        Dim datePredicate As Func(Of FileInfo, Boolean) =
            Function(fi) fi.CreationTime >= from_date AndAlso fi.CreationTime <= to_date

        CopyFiles(folder, destDirectory,
            "??????????????????????inscriz*.PDF", datePredicate)
        CopyFiles(folder, destDirectory,
            "??????????????????????inscriz*.XLS", datePredicate)
        CopyFiles(folder, destDirectory,
            "??????????????????????inscriz*.XLSX", datePredicate)
        CopyFiles(folder, destDirectory,
            "??????????????????????inscriz*.csv", datePredicate)
    Catch ex As Exception
        MessageBox.Show(ex.Message)
    End Try
End Sub

Private Sub CopyFiles(source As DirectoryInfo, destDirectory As String,
                      fileFilter As String,
                      dateFilter As Func(Of FileInfo, Boolean))

    Dim fileList = source.EnumerateFiles(fileFilter).Where(dateFilter)

    For Each file In fileList
        file.CopyTo(Path.Combine(destDirectory, file.Name))
    Next
End Sub